* [PATCH v1 01/14] mm: memcg: introduce memcontrol-v1.c
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
@ 2024-05-28 20:20 ` Roman Gushchin
2024-06-01 6:42 ` Shakeel Butt
2024-05-28 20:20 ` [PATCH v1 02/14] mm: memcg: move soft limit reclaim code to memcontrol-v1.c Roman Gushchin
` (10 subsequent siblings)
11 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:20 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
This patch introduces the mm/memcontrol-v1.c source file which will be used for
all legacy (cgroup v1) memory cgroup code. It also introduces mm/memcontrol-v1.h
to keep declarations shared between mm/memcontrol.c and mm/memcontrol-v1.c.
As of now, let's compile it if CONFIG_MEMCG is set, similar to mm/memcontrol.c.
Later on it can be switched to use a separate config option, so that the legacy
code won't be compiled if not required.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/Makefile | 3 ++-
mm/memcontrol-v1.c | 3 +++
mm/memcontrol-v1.h | 7 +++++++
3 files changed, 12 insertions(+), 1 deletion(-)
create mode 100644 mm/memcontrol-v1.c
create mode 100644 mm/memcontrol-v1.h
diff --git a/mm/Makefile b/mm/Makefile
index 8fb85acda1b1c..124d4dea20351 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -26,6 +26,7 @@ KCOV_INSTRUMENT_page_alloc.o := n
KCOV_INSTRUMENT_debug-pagealloc.o := n
KCOV_INSTRUMENT_kmemleak.o := n
KCOV_INSTRUMENT_memcontrol.o := n
+KCOV_INSTRUMENT_memcontrol-v1.o := n
KCOV_INSTRUMENT_mmzone.o := n
KCOV_INSTRUMENT_vmstat.o := n
KCOV_INSTRUMENT_failslab.o := n
@@ -95,7 +96,7 @@ obj-$(CONFIG_NUMA) += memory-tiers.o
obj-$(CONFIG_DEVICE_MIGRATION) += migrate_device.o
obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o
obj-$(CONFIG_PAGE_COUNTER) += page_counter.o
-obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o
+obj-$(CONFIG_MEMCG) += memcontrol.o memcontrol-v1.o vmpressure.o
ifdef CONFIG_SWAP
obj-$(CONFIG_MEMCG) += swap_cgroup.o
endif
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
new file mode 100644
index 0000000000000..a941446ba575b
--- /dev/null
+++ b/mm/memcontrol-v1.c
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "memcontrol-v1.h"
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
new file mode 100644
index 0000000000000..7c5f094755ff8
--- /dev/null
+++ b/mm/memcontrol-v1.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __MM_MEMCONTROL_V1_H
+#define __MM_MEMCONTROL_V1_H
+
+
+#endif /* __MM_MEMCONTROL_V1_H */
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 01/14] mm: memcg: introduce memcontrol-v1.c
2024-05-28 20:20 ` [PATCH v1 01/14] mm: memcg: introduce memcontrol-v1.c Roman Gushchin
@ 2024-06-01 6:42 ` Shakeel Butt
2024-06-04 3:58 ` Roman Gushchin
0 siblings, 1 reply; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:42 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:53PM GMT, Roman Gushchin wrote:
> This patch introduces the mm/memcontrol-v1.c source file which will be used for
> all legacy (cgroup v1) memory cgroup code. It also introduces mm/memcontrol-v1.h
> to keep declarations shared between mm/memcontrol.c and mm/memcontrol-v1.c.
>
> As of now, let's compile it if CONFIG_MEMCG is set, similar to mm/memcontrol.c.
> Later on it can be switched to use a separate config option, so that the legacy
> code won't be compiled if not required.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 01/14] mm: memcg: introduce memcontrol-v1.c
2024-06-01 6:42 ` Shakeel Butt
@ 2024-06-04 3:58 ` Roman Gushchin
0 siblings, 0 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-06-04 3:58 UTC (permalink / raw)
To: Shakeel Butt
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Fri, May 31, 2024 at 11:42:26PM -0700, Shakeel Butt wrote:
> On Tue, May 28, 2024 at 01:20:53PM GMT, Roman Gushchin wrote:
> > This patch introduces the mm/memcontrol-v1.c source file which will be used for
> > all legacy (cgroup v1) memory cgroup code. It also introduces mm/memcontrol-v1.h
> > to keep declarations shared between mm/memcontrol.c and mm/memcontrol-v1.c.
> >
> > As of now, let's compile it if CONFIG_MEMCG is set, similar to mm/memcontrol.c.
> > Later on it can be switched to use a separate config option, so that the legacy
> > code won't be compiled if not required.
> >
> > Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
>
> Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Thank you for reviewing the series!
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 02/14] mm: memcg: move soft limit reclaim code to memcontrol-v1.c
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
2024-05-28 20:20 ` [PATCH v1 01/14] mm: memcg: introduce memcontrol-v1.c Roman Gushchin
@ 2024-05-28 20:20 ` Roman Gushchin
2024-06-01 6:42 ` Shakeel Butt
2024-05-28 20:20 ` [PATCH v1 03/14] mm: memcg: rename soft limit reclaim-related functions Roman Gushchin
` (9 subsequent siblings)
11 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:20 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Soft limits are cgroup v1-specific and are not supported by cgroup v2,
so let's move the corresponding code into memcontrol-v1.c.
Aside from simple moving the code, this commits introduces a trivial
memcg1_soft_limit_reset() function to reset soft limits and also
moves the global soft limit tree initialization code into a new
memcg1_init() function.
It also moves corresponding declarations shared between memcontrol.c
and memcontrol-v1.c into mm/memcontrol-v1.h.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 342 +++++++++++++++++++++++++++++++++++++++++++++
mm/memcontrol-v1.h | 7 +
mm/memcontrol.c | 337 +-------------------------------------------
3 files changed, 353 insertions(+), 333 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index a941446ba575b..2ccb8406fa84e 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1,3 +1,345 @@
// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/memcontrol.h>
+#include <linux/swap.h>
+#include <linux/mm_inline.h>
+
#include "memcontrol-v1.h"
+
+/*
+ * Cgroups above their limits are maintained in a RB-Tree, independent of
+ * their hierarchy representation
+ */
+
+struct mem_cgroup_tree_per_node {
+ struct rb_root rb_root;
+ struct rb_node *rb_rightmost;
+ spinlock_t lock;
+};
+
+struct mem_cgroup_tree {
+ struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
+};
+
+static struct mem_cgroup_tree soft_limit_tree __read_mostly;
+
+/*
+ * Maximum loops in mem_cgroup_soft_reclaim(), used for soft
+ * limit reclaim to prevent infinite loops, if they ever occur.
+ */
+#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
+#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
+
+static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
+ struct mem_cgroup_tree_per_node *mctz,
+ unsigned long new_usage_in_excess)
+{
+ struct rb_node **p = &mctz->rb_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct mem_cgroup_per_node *mz_node;
+ bool rightmost = true;
+
+ if (mz->on_tree)
+ return;
+
+ mz->usage_in_excess = new_usage_in_excess;
+ if (!mz->usage_in_excess)
+ return;
+ while (*p) {
+ parent = *p;
+ mz_node = rb_entry(parent, struct mem_cgroup_per_node,
+ tree_node);
+ if (mz->usage_in_excess < mz_node->usage_in_excess) {
+ p = &(*p)->rb_left;
+ rightmost = false;
+ } else {
+ p = &(*p)->rb_right;
+ }
+ }
+
+ if (rightmost)
+ mctz->rb_rightmost = &mz->tree_node;
+
+ rb_link_node(&mz->tree_node, parent, p);
+ rb_insert_color(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = true;
+}
+
+static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz,
+ struct mem_cgroup_tree_per_node *mctz)
+{
+ if (!mz->on_tree)
+ return;
+
+ if (&mz->tree_node == mctz->rb_rightmost)
+ mctz->rb_rightmost = rb_prev(&mz->tree_node);
+
+ rb_erase(&mz->tree_node, &mctz->rb_root);
+ mz->on_tree = false;
+}
+
+static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz,
+ struct mem_cgroup_tree_per_node *mctz)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
+ __mem_cgroup_remove_exceeded(mz, mctz);
+ spin_unlock_irqrestore(&mctz->lock, flags);
+}
+
+static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
+{
+ unsigned long nr_pages = page_counter_read(&memcg->memory);
+ unsigned long soft_limit = READ_ONCE(memcg->soft_limit);
+ unsigned long excess = 0;
+
+ if (nr_pages > soft_limit)
+ excess = nr_pages - soft_limit;
+
+ return excess;
+}
+
+void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid)
+{
+ unsigned long excess;
+ struct mem_cgroup_per_node *mz;
+ struct mem_cgroup_tree_per_node *mctz;
+
+ if (lru_gen_enabled()) {
+ if (soft_limit_excess(memcg))
+ lru_gen_soft_reclaim(memcg, nid);
+ return;
+ }
+
+ mctz = soft_limit_tree.rb_tree_per_node[nid];
+ if (!mctz)
+ return;
+ /*
+ * Necessary to update all ancestors when hierarchy is used.
+ * because their event counter is not touched.
+ */
+ for (; memcg; memcg = parent_mem_cgroup(memcg)) {
+ mz = memcg->nodeinfo[nid];
+ excess = soft_limit_excess(memcg);
+ /*
+ * We have to update the tree if mz is on RB-tree or
+ * mem is over its softlimit.
+ */
+ if (excess || mz->on_tree) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&mctz->lock, flags);
+ /* if on-tree, remove it */
+ if (mz->on_tree)
+ __mem_cgroup_remove_exceeded(mz, mctz);
+ /*
+ * Insert again. mz->usage_in_excess will be updated.
+ * If excess is 0, no tree ops.
+ */
+ __mem_cgroup_insert_exceeded(mz, mctz, excess);
+ spin_unlock_irqrestore(&mctz->lock, flags);
+ }
+ }
+}
+
+void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_tree_per_node *mctz;
+ struct mem_cgroup_per_node *mz;
+ int nid;
+
+ for_each_node(nid) {
+ mz = memcg->nodeinfo[nid];
+ mctz = soft_limit_tree.rb_tree_per_node[nid];
+ if (mctz)
+ mem_cgroup_remove_exceeded(mz, mctz);
+ }
+}
+
+static struct mem_cgroup_per_node *
+__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz)
+{
+ struct mem_cgroup_per_node *mz;
+
+retry:
+ mz = NULL;
+ if (!mctz->rb_rightmost)
+ goto done; /* Nothing to reclaim from */
+
+ mz = rb_entry(mctz->rb_rightmost,
+ struct mem_cgroup_per_node, tree_node);
+ /*
+ * Remove the node now but someone else can add it back,
+ * we will to add it back at the end of reclaim to its correct
+ * position in the tree.
+ */
+ __mem_cgroup_remove_exceeded(mz, mctz);
+ if (!soft_limit_excess(mz->memcg) ||
+ !css_tryget(&mz->memcg->css))
+ goto retry;
+done:
+ return mz;
+}
+
+static struct mem_cgroup_per_node *
+mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz)
+{
+ struct mem_cgroup_per_node *mz;
+
+ spin_lock_irq(&mctz->lock);
+ mz = __mem_cgroup_largest_soft_limit_node(mctz);
+ spin_unlock_irq(&mctz->lock);
+ return mz;
+}
+
+static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
+ pg_data_t *pgdat,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ struct mem_cgroup *victim = NULL;
+ int total = 0;
+ int loop = 0;
+ unsigned long excess;
+ unsigned long nr_scanned;
+ struct mem_cgroup_reclaim_cookie reclaim = {
+ .pgdat = pgdat,
+ };
+
+ excess = soft_limit_excess(root_memcg);
+
+ while (1) {
+ victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
+ if (!victim) {
+ loop++;
+ if (loop >= 2) {
+ /*
+ * If we have not been able to reclaim
+ * anything, it might because there are
+ * no reclaimable pages under this hierarchy
+ */
+ if (!total)
+ break;
+ /*
+ * We want to do more targeted reclaim.
+ * excess >> 2 is not to excessive so as to
+ * reclaim too much, nor too less that we keep
+ * coming back to reclaim from this cgroup
+ */
+ if (total >= (excess >> 2) ||
+ (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
+ break;
+ }
+ continue;
+ }
+ total += mem_cgroup_shrink_node(victim, gfp_mask, false,
+ pgdat, &nr_scanned);
+ *total_scanned += nr_scanned;
+ if (!soft_limit_excess(root_memcg))
+ break;
+ }
+ mem_cgroup_iter_break(root_memcg, victim);
+ return total;
+}
+
+unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ unsigned long nr_reclaimed = 0;
+ struct mem_cgroup_per_node *mz, *next_mz = NULL;
+ unsigned long reclaimed;
+ int loop = 0;
+ struct mem_cgroup_tree_per_node *mctz;
+ unsigned long excess;
+
+ if (lru_gen_enabled())
+ return 0;
+
+ if (order > 0)
+ return 0;
+
+ mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id];
+
+ /*
+ * Do not even bother to check the largest node if the root
+ * is empty. Do it lockless to prevent lock bouncing. Races
+ * are acceptable as soft limit is best effort anyway.
+ */
+ if (!mctz || RB_EMPTY_ROOT(&mctz->rb_root))
+ return 0;
+
+ /*
+ * This loop can run a while, specially if mem_cgroup's continuously
+ * keep exceeding their soft limit and putting the system under
+ * pressure
+ */
+ do {
+ if (next_mz)
+ mz = next_mz;
+ else
+ mz = mem_cgroup_largest_soft_limit_node(mctz);
+ if (!mz)
+ break;
+
+ reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat,
+ gfp_mask, total_scanned);
+ nr_reclaimed += reclaimed;
+ spin_lock_irq(&mctz->lock);
+
+ /*
+ * If we failed to reclaim anything from this memory cgroup
+ * it is time to move on to the next cgroup
+ */
+ next_mz = NULL;
+ if (!reclaimed)
+ next_mz = __mem_cgroup_largest_soft_limit_node(mctz);
+
+ excess = soft_limit_excess(mz->memcg);
+ /*
+ * One school of thought says that we should not add
+ * back the node to the tree if reclaim returns 0.
+ * But our reclaim could return 0, simply because due
+ * to priority we are exposing a smaller subset of
+ * memory to reclaim from. Consider this as a longer
+ * term TODO.
+ */
+ /* If excess == 0, no tree ops */
+ __mem_cgroup_insert_exceeded(mz, mctz, excess);
+ spin_unlock_irq(&mctz->lock);
+ css_put(&mz->memcg->css);
+ loop++;
+ /*
+ * Could not reclaim anything and there are no more
+ * mem cgroups to try or we seem to be looping without
+ * reclaiming anything.
+ */
+ if (!nr_reclaimed &&
+ (next_mz == NULL ||
+ loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
+ break;
+ } while (!nr_reclaimed);
+ if (next_mz)
+ css_put(&next_mz->memcg->css);
+ return nr_reclaimed;
+}
+
+static int __init memcg1_init(void)
+{
+ int node;
+
+ for_each_node(node) {
+ struct mem_cgroup_tree_per_node *rtpn;
+
+ rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node);
+
+ rtpn->rb_root = RB_ROOT;
+ rtpn->rb_rightmost = NULL;
+ spin_lock_init(&rtpn->lock);
+ soft_limit_tree.rb_tree_per_node[node] = rtpn;
+ }
+
+ return 0;
+}
+subsys_initcall(memcg1_init);
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 7c5f094755ff8..4da6fa561c6d4 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -3,5 +3,12 @@
#ifndef __MM_MEMCONTROL_V1_H
#define __MM_MEMCONTROL_V1_H
+void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid);
+void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg);
+
+static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
+{
+ WRITE_ONCE(memcg->soft_limit, PAGE_COUNTER_MAX);
+}
#endif /* __MM_MEMCONTROL_V1_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 352b6cda962ce..fa1df6e894787 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -72,6 +72,7 @@
#include <net/ip.h>
#include "slab.h"
#include "swap.h"
+#include "memcontrol-v1.h"
#include <linux/uaccess.h>
@@ -108,23 +109,6 @@ static bool do_memsw_account(void)
#define THRESHOLDS_EVENTS_TARGET 128
#define SOFTLIMIT_EVENTS_TARGET 1024
-/*
- * Cgroups above their limits are maintained in a RB-Tree, independent of
- * their hierarchy representation
- */
-
-struct mem_cgroup_tree_per_node {
- struct rb_root rb_root;
- struct rb_node *rb_rightmost;
- spinlock_t lock;
-};
-
-struct mem_cgroup_tree {
- struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
-};
-
-static struct mem_cgroup_tree soft_limit_tree __read_mostly;
-
/* for OOM */
struct mem_cgroup_eventfd_list {
struct list_head list;
@@ -199,13 +183,6 @@ static struct move_charge_struct {
.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
};
-/*
- * Maximum loops in mem_cgroup_soft_reclaim(), used for soft
- * limit reclaim to prevent infinite loops, if they ever occur.
- */
-#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
-#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
-
/* for encoding cft->private value on file */
enum res_type {
_MEM,
@@ -413,169 +390,6 @@ ino_t page_cgroup_ino(struct page *page)
return ino;
}
-static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
- struct mem_cgroup_tree_per_node *mctz,
- unsigned long new_usage_in_excess)
-{
- struct rb_node **p = &mctz->rb_root.rb_node;
- struct rb_node *parent = NULL;
- struct mem_cgroup_per_node *mz_node;
- bool rightmost = true;
-
- if (mz->on_tree)
- return;
-
- mz->usage_in_excess = new_usage_in_excess;
- if (!mz->usage_in_excess)
- return;
- while (*p) {
- parent = *p;
- mz_node = rb_entry(parent, struct mem_cgroup_per_node,
- tree_node);
- if (mz->usage_in_excess < mz_node->usage_in_excess) {
- p = &(*p)->rb_left;
- rightmost = false;
- } else {
- p = &(*p)->rb_right;
- }
- }
-
- if (rightmost)
- mctz->rb_rightmost = &mz->tree_node;
-
- rb_link_node(&mz->tree_node, parent, p);
- rb_insert_color(&mz->tree_node, &mctz->rb_root);
- mz->on_tree = true;
-}
-
-static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz,
- struct mem_cgroup_tree_per_node *mctz)
-{
- if (!mz->on_tree)
- return;
-
- if (&mz->tree_node == mctz->rb_rightmost)
- mctz->rb_rightmost = rb_prev(&mz->tree_node);
-
- rb_erase(&mz->tree_node, &mctz->rb_root);
- mz->on_tree = false;
-}
-
-static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz,
- struct mem_cgroup_tree_per_node *mctz)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&mctz->lock, flags);
- __mem_cgroup_remove_exceeded(mz, mctz);
- spin_unlock_irqrestore(&mctz->lock, flags);
-}
-
-static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
-{
- unsigned long nr_pages = page_counter_read(&memcg->memory);
- unsigned long soft_limit = READ_ONCE(memcg->soft_limit);
- unsigned long excess = 0;
-
- if (nr_pages > soft_limit)
- excess = nr_pages - soft_limit;
-
- return excess;
-}
-
-static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid)
-{
- unsigned long excess;
- struct mem_cgroup_per_node *mz;
- struct mem_cgroup_tree_per_node *mctz;
-
- if (lru_gen_enabled()) {
- if (soft_limit_excess(memcg))
- lru_gen_soft_reclaim(memcg, nid);
- return;
- }
-
- mctz = soft_limit_tree.rb_tree_per_node[nid];
- if (!mctz)
- return;
- /*
- * Necessary to update all ancestors when hierarchy is used.
- * because their event counter is not touched.
- */
- for (; memcg; memcg = parent_mem_cgroup(memcg)) {
- mz = memcg->nodeinfo[nid];
- excess = soft_limit_excess(memcg);
- /*
- * We have to update the tree if mz is on RB-tree or
- * mem is over its softlimit.
- */
- if (excess || mz->on_tree) {
- unsigned long flags;
-
- spin_lock_irqsave(&mctz->lock, flags);
- /* if on-tree, remove it */
- if (mz->on_tree)
- __mem_cgroup_remove_exceeded(mz, mctz);
- /*
- * Insert again. mz->usage_in_excess will be updated.
- * If excess is 0, no tree ops.
- */
- __mem_cgroup_insert_exceeded(mz, mctz, excess);
- spin_unlock_irqrestore(&mctz->lock, flags);
- }
- }
-}
-
-static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
-{
- struct mem_cgroup_tree_per_node *mctz;
- struct mem_cgroup_per_node *mz;
- int nid;
-
- for_each_node(nid) {
- mz = memcg->nodeinfo[nid];
- mctz = soft_limit_tree.rb_tree_per_node[nid];
- if (mctz)
- mem_cgroup_remove_exceeded(mz, mctz);
- }
-}
-
-static struct mem_cgroup_per_node *
-__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz)
-{
- struct mem_cgroup_per_node *mz;
-
-retry:
- mz = NULL;
- if (!mctz->rb_rightmost)
- goto done; /* Nothing to reclaim from */
-
- mz = rb_entry(mctz->rb_rightmost,
- struct mem_cgroup_per_node, tree_node);
- /*
- * Remove the node now but someone else can add it back,
- * we will to add it back at the end of reclaim to its correct
- * position in the tree.
- */
- __mem_cgroup_remove_exceeded(mz, mctz);
- if (!soft_limit_excess(mz->memcg) ||
- !css_tryget(&mz->memcg->css))
- goto retry;
-done:
- return mz;
-}
-
-static struct mem_cgroup_per_node *
-mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz)
-{
- struct mem_cgroup_per_node *mz;
-
- spin_lock_irq(&mctz->lock);
- mz = __mem_cgroup_largest_soft_limit_node(mctz);
- spin_unlock_irq(&mctz->lock);
- return mz;
-}
-
/* Subset of node_stat_item for memcg stats */
static const unsigned int memcg_node_stat_items[] = {
NR_INACTIVE_ANON,
@@ -1980,56 +1794,6 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
return ret;
}
-static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
- pg_data_t *pgdat,
- gfp_t gfp_mask,
- unsigned long *total_scanned)
-{
- struct mem_cgroup *victim = NULL;
- int total = 0;
- int loop = 0;
- unsigned long excess;
- unsigned long nr_scanned;
- struct mem_cgroup_reclaim_cookie reclaim = {
- .pgdat = pgdat,
- };
-
- excess = soft_limit_excess(root_memcg);
-
- while (1) {
- victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
- if (!victim) {
- loop++;
- if (loop >= 2) {
- /*
- * If we have not been able to reclaim
- * anything, it might because there are
- * no reclaimable pages under this hierarchy
- */
- if (!total)
- break;
- /*
- * We want to do more targeted reclaim.
- * excess >> 2 is not to excessive so as to
- * reclaim too much, nor too less that we keep
- * coming back to reclaim from this cgroup
- */
- if (total >= (excess >> 2) ||
- (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
- break;
- }
- continue;
- }
- total += mem_cgroup_shrink_node(victim, gfp_mask, false,
- pgdat, &nr_scanned);
- *total_scanned += nr_scanned;
- if (!soft_limit_excess(root_memcg))
- break;
- }
- mem_cgroup_iter_break(root_memcg, victim);
- return total;
-}
-
#ifdef CONFIG_LOCKDEP
static struct lockdep_map memcg_oom_lock_dep_map = {
.name = "memcg_oom_lock",
@@ -3927,88 +3691,6 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg,
return ret;
}
-unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
- gfp_t gfp_mask,
- unsigned long *total_scanned)
-{
- unsigned long nr_reclaimed = 0;
- struct mem_cgroup_per_node *mz, *next_mz = NULL;
- unsigned long reclaimed;
- int loop = 0;
- struct mem_cgroup_tree_per_node *mctz;
- unsigned long excess;
-
- if (lru_gen_enabled())
- return 0;
-
- if (order > 0)
- return 0;
-
- mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id];
-
- /*
- * Do not even bother to check the largest node if the root
- * is empty. Do it lockless to prevent lock bouncing. Races
- * are acceptable as soft limit is best effort anyway.
- */
- if (!mctz || RB_EMPTY_ROOT(&mctz->rb_root))
- return 0;
-
- /*
- * This loop can run a while, specially if mem_cgroup's continuously
- * keep exceeding their soft limit and putting the system under
- * pressure
- */
- do {
- if (next_mz)
- mz = next_mz;
- else
- mz = mem_cgroup_largest_soft_limit_node(mctz);
- if (!mz)
- break;
-
- reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat,
- gfp_mask, total_scanned);
- nr_reclaimed += reclaimed;
- spin_lock_irq(&mctz->lock);
-
- /*
- * If we failed to reclaim anything from this memory cgroup
- * it is time to move on to the next cgroup
- */
- next_mz = NULL;
- if (!reclaimed)
- next_mz = __mem_cgroup_largest_soft_limit_node(mctz);
-
- excess = soft_limit_excess(mz->memcg);
- /*
- * One school of thought says that we should not add
- * back the node to the tree if reclaim returns 0.
- * But our reclaim could return 0, simply because due
- * to priority we are exposing a smaller subset of
- * memory to reclaim from. Consider this as a longer
- * term TODO.
- */
- /* If excess == 0, no tree ops */
- __mem_cgroup_insert_exceeded(mz, mctz, excess);
- spin_unlock_irq(&mctz->lock);
- css_put(&mz->memcg->css);
- loop++;
- /*
- * Could not reclaim anything and there are no more
- * mem cgroups to try or we seem to be looping without
- * reclaiming anything.
- */
- if (!nr_reclaimed &&
- (next_mz == NULL ||
- loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
- break;
- } while (!nr_reclaimed);
- if (next_mz)
- css_put(&next_mz->memcg->css);
- return nr_reclaimed;
-}
-
/*
* Reclaims as many pages from the given memcg as possible.
*
@@ -5786,7 +5468,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
return ERR_CAST(memcg);
page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX);
- WRITE_ONCE(memcg->soft_limit, PAGE_COUNTER_MAX);
+ memcg1_soft_limit_reset(memcg);
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
memcg->zswap_max = PAGE_COUNTER_MAX;
WRITE_ONCE(memcg->zswap_writeback,
@@ -5959,7 +5641,7 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
page_counter_set_min(&memcg->memory, 0);
page_counter_set_low(&memcg->memory, 0);
page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX);
- WRITE_ONCE(memcg->soft_limit, PAGE_COUNTER_MAX);
+ memcg1_soft_limit_reset(memcg);
page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX);
memcg_wb_domain_size_changed(memcg);
}
@@ -7986,7 +7668,7 @@ __setup("cgroup.memory=", cgroup_memory);
*/
static int __init mem_cgroup_init(void)
{
- int cpu, node;
+ int cpu;
/*
* Currently s32 type (can refer to struct batched_lruvec_stat) is
@@ -8003,17 +7685,6 @@ static int __init mem_cgroup_init(void)
INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,
drain_local_stock);
- for_each_node(node) {
- struct mem_cgroup_tree_per_node *rtpn;
-
- rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node);
-
- rtpn->rb_root = RB_ROOT;
- rtpn->rb_rightmost = NULL;
- spin_lock_init(&rtpn->lock);
- soft_limit_tree.rb_tree_per_node[node] = rtpn;
- }
-
return 0;
}
subsys_initcall(mem_cgroup_init);
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 02/14] mm: memcg: move soft limit reclaim code to memcontrol-v1.c
2024-05-28 20:20 ` [PATCH v1 02/14] mm: memcg: move soft limit reclaim code to memcontrol-v1.c Roman Gushchin
@ 2024-06-01 6:42 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:42 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:54PM GMT, Roman Gushchin wrote:
> Soft limits are cgroup v1-specific and are not supported by cgroup v2,
> so let's move the corresponding code into memcontrol-v1.c.
>
> Aside from simple moving the code, this commits introduces a trivial
> memcg1_soft_limit_reset() function to reset soft limits and also
> moves the global soft limit tree initialization code into a new
> memcg1_init() function.
>
> It also moves corresponding declarations shared between memcontrol.c
> and memcontrol-v1.c into mm/memcontrol-v1.h.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 03/14] mm: memcg: rename soft limit reclaim-related functions
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
2024-05-28 20:20 ` [PATCH v1 01/14] mm: memcg: introduce memcontrol-v1.c Roman Gushchin
2024-05-28 20:20 ` [PATCH v1 02/14] mm: memcg: move soft limit reclaim code to memcontrol-v1.c Roman Gushchin
@ 2024-05-28 20:20 ` Roman Gushchin
2024-06-01 6:43 ` Shakeel Butt
2024-05-28 20:20 ` [PATCH v1 04/14] mm: memcg: move charge migration code to memcontrol-v1.c Roman Gushchin
` (8 subsequent siblings)
11 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:20 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Rename exported function related to the softlimit reclaim
to have memcg1_ prefix.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
include/linux/memcontrol.h | 12 ++++++------
mm/memcontrol-v1.c | 6 +++---
mm/memcontrol-v1.h | 4 ++--
mm/memcontrol.c | 4 ++--
mm/vmscan.c | 10 +++++-----
5 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3d1599146afe4..04f9f7b0e7c2f 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1115,9 +1115,9 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
void split_page_memcg(struct page *head, int old_order, int new_order);
-unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
- gfp_t gfp_mask,
- unsigned long *total_scanned);
+unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned);
#else /* CONFIG_MEMCG */
@@ -1566,9 +1566,9 @@ static inline void split_page_memcg(struct page *head, int old_order, int new_or
}
static inline
-unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
- gfp_t gfp_mask,
- unsigned long *total_scanned)
+unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
{
return 0;
}
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 2ccb8406fa84e..68e2f1a718d36 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -100,7 +100,7 @@ static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
return excess;
}
-void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid)
+void memcg1_update_tree(struct mem_cgroup *memcg, int nid)
{
unsigned long excess;
struct mem_cgroup_per_node *mz;
@@ -143,7 +143,7 @@ void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid)
}
}
-void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
+void memcg1_remove_from_trees(struct mem_cgroup *memcg)
{
struct mem_cgroup_tree_per_node *mctz;
struct mem_cgroup_per_node *mz;
@@ -243,7 +243,7 @@ static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
return total;
}
-unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
+unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
gfp_t gfp_mask,
unsigned long *total_scanned)
{
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 4da6fa561c6d4..e37bc7e8d9558 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -3,8 +3,8 @@
#ifndef __MM_MEMCONTROL_V1_H
#define __MM_MEMCONTROL_V1_H
-void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid);
-void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg);
+void memcg1_update_tree(struct mem_cgroup *memcg, int nid);
+void memcg1_remove_from_trees(struct mem_cgroup *memcg);
static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
{
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fa1df6e894787..0fbc4e518222e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1012,7 +1012,7 @@ static void memcg_check_events(struct mem_cgroup *memcg, int nid)
MEM_CGROUP_TARGET_SOFTLIMIT);
mem_cgroup_threshold(memcg);
if (unlikely(do_softlimit))
- mem_cgroup_update_tree(memcg, nid);
+ memcg1_update_tree(memcg, nid);
}
}
@@ -5612,7 +5612,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
vmpressure_cleanup(&memcg->vmpressure);
cancel_work_sync(&memcg->high_work);
- mem_cgroup_remove_from_trees(memcg);
+ memcg1_remove_from_trees(memcg);
free_shrinker_info(memcg);
mem_cgroup_free(memcg);
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b9170f767353d..3833b11c96f9b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -6187,9 +6187,9 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
* and balancing, not for a memcg's limit.
*/
nr_soft_scanned = 0;
- nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone->zone_pgdat,
- sc->order, sc->gfp_mask,
- &nr_soft_scanned);
+ nr_soft_reclaimed = memcg1_soft_limit_reclaim(zone->zone_pgdat,
+ sc->order, sc->gfp_mask,
+ &nr_soft_scanned);
sc->nr_reclaimed += nr_soft_reclaimed;
sc->nr_scanned += nr_soft_scanned;
/* need some check for avoid more shrink_zone() */
@@ -6952,8 +6952,8 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int highest_zoneidx)
/* Call soft limit reclaim before calling shrink_node. */
sc.nr_scanned = 0;
nr_soft_scanned = 0;
- nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(pgdat, sc.order,
- sc.gfp_mask, &nr_soft_scanned);
+ nr_soft_reclaimed = memcg1_soft_limit_reclaim(pgdat, sc.order,
+ sc.gfp_mask, &nr_soft_scanned);
sc.nr_reclaimed += nr_soft_reclaimed;
/*
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 03/14] mm: memcg: rename soft limit reclaim-related functions
2024-05-28 20:20 ` [PATCH v1 03/14] mm: memcg: rename soft limit reclaim-related functions Roman Gushchin
@ 2024-06-01 6:43 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:43 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:55PM GMT, Roman Gushchin wrote:
> Rename exported function related to the softlimit reclaim
> to have memcg1_ prefix.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 04/14] mm: memcg: move charge migration code to memcontrol-v1.c
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (2 preceding siblings ...)
2024-05-28 20:20 ` [PATCH v1 03/14] mm: memcg: rename soft limit reclaim-related functions Roman Gushchin
@ 2024-05-28 20:20 ` Roman Gushchin
2024-06-01 6:44 ` Shakeel Butt
2024-05-28 20:20 ` [PATCH v1 05/14] mm: memcg: rename charge move-related functions Roman Gushchin
` (7 subsequent siblings)
11 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:20 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Unlike the legacy cgroup v1 memory controller, cgroup v2 memory
controller doesn't support moving charged pages between cgroups.
It's a fairly large and complicated code which created a number
of problems in the past. Let's move this code into memcontrol-v1.c.
It shaves off 1k lines from memcontrol.c. It's also another step
towards making the legacy memory controller code optionally compiled.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 981 +++++++++++++++++++++++++++++++++++++++++++
mm/memcontrol-v1.h | 30 ++
mm/memcontrol.c | 1004 +-------------------------------------------
3 files changed, 1019 insertions(+), 996 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 68e2f1a718d36..f4c8bec5ae1b8 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -3,7 +3,12 @@
#include <linux/memcontrol.h>
#include <linux/swap.h>
#include <linux/mm_inline.h>
+#include <linux/pagewalk.h>
+#include <linux/backing-dev.h>
+#include <linux/swap_cgroup.h>
+#include "internal.h"
+#include "swap.h"
#include "memcontrol-v1.h"
/*
@@ -30,6 +35,31 @@ static struct mem_cgroup_tree soft_limit_tree __read_mostly;
#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
+/* Stuffs for move charges at task migration. */
+/*
+ * Types of charges to be moved.
+ */
+#define MOVE_ANON 0x1U
+#define MOVE_FILE 0x2U
+#define MOVE_MASK (MOVE_ANON | MOVE_FILE)
+
+/* "mc" and its members are protected by cgroup_mutex */
+static struct move_charge_struct {
+ spinlock_t lock; /* for from, to */
+ struct mm_struct *mm;
+ struct mem_cgroup *from;
+ struct mem_cgroup *to;
+ unsigned long flags;
+ unsigned long precharge;
+ unsigned long moved_charge;
+ unsigned long moved_swap;
+ struct task_struct *moving_task; /* a task moving charges */
+ wait_queue_head_t waitq; /* a waitq for other context */
+} mc = {
+ .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
+ .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
+};
+
static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
struct mem_cgroup_tree_per_node *mctz,
unsigned long new_usage_in_excess)
@@ -325,6 +355,957 @@ unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
return nr_reclaimed;
}
+/*
+ * A routine for checking "mem" is under move_account() or not.
+ *
+ * Checking a cgroup is mc.from or mc.to or under hierarchy of
+ * moving cgroups. This is for waiting at high-memory pressure
+ * caused by "move".
+ */
+static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *from;
+ struct mem_cgroup *to;
+ bool ret = false;
+ /*
+ * Unlike task_move routines, we access mc.to, mc.from not under
+ * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
+ */
+ spin_lock(&mc.lock);
+ from = mc.from;
+ to = mc.to;
+ if (!from)
+ goto unlock;
+
+ ret = mem_cgroup_is_descendant(from, memcg) ||
+ mem_cgroup_is_descendant(to, memcg);
+unlock:
+ spin_unlock(&mc.lock);
+ return ret;
+}
+
+bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
+{
+ if (mc.moving_task && current != mc.moving_task) {
+ if (mem_cgroup_under_move(memcg)) {
+ DEFINE_WAIT(wait);
+ prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
+ /* moving charge context might have finished. */
+ if (mc.moving_task)
+ schedule();
+ finish_wait(&mc.waitq, &wait);
+ return true;
+ }
+ }
+ return false;
+}
+
+/**
+ * folio_memcg_lock - Bind a folio to its memcg.
+ * @folio: The folio.
+ *
+ * This function prevents unlocked LRU folios from being moved to
+ * another cgroup.
+ *
+ * It ensures lifetime of the bound memcg. The caller is responsible
+ * for the lifetime of the folio.
+ */
+void folio_memcg_lock(struct folio *folio)
+{
+ struct mem_cgroup *memcg;
+ unsigned long flags;
+
+ /*
+ * The RCU lock is held throughout the transaction. The fast
+ * path can get away without acquiring the memcg->move_lock
+ * because page moving starts with an RCU grace period.
+ */
+ rcu_read_lock();
+
+ if (mem_cgroup_disabled())
+ return;
+again:
+ memcg = folio_memcg(folio);
+ if (unlikely(!memcg))
+ return;
+
+#ifdef CONFIG_PROVE_LOCKING
+ local_irq_save(flags);
+ might_lock(&memcg->move_lock);
+ local_irq_restore(flags);
+#endif
+
+ if (atomic_read(&memcg->moving_account) <= 0)
+ return;
+
+ spin_lock_irqsave(&memcg->move_lock, flags);
+ if (memcg != folio_memcg(folio)) {
+ spin_unlock_irqrestore(&memcg->move_lock, flags);
+ goto again;
+ }
+
+ /*
+ * When charge migration first begins, we can have multiple
+ * critical sections holding the fast-path RCU lock and one
+ * holding the slowpath move_lock. Track the task who has the
+ * move_lock for folio_memcg_unlock().
+ */
+ memcg->move_lock_task = current;
+ memcg->move_lock_flags = flags;
+}
+
+static void __folio_memcg_unlock(struct mem_cgroup *memcg)
+{
+ if (memcg && memcg->move_lock_task == current) {
+ unsigned long flags = memcg->move_lock_flags;
+
+ memcg->move_lock_task = NULL;
+ memcg->move_lock_flags = 0;
+
+ spin_unlock_irqrestore(&memcg->move_lock, flags);
+ }
+
+ rcu_read_unlock();
+}
+
+/**
+ * folio_memcg_unlock - Release the binding between a folio and its memcg.
+ * @folio: The folio.
+ *
+ * This releases the binding created by folio_memcg_lock(). This does
+ * not change the accounting of this folio to its memcg, but it does
+ * permit others to change it.
+ */
+void folio_memcg_unlock(struct folio *folio)
+{
+ __folio_memcg_unlock(folio_memcg(folio));
+}
+
+#ifdef CONFIG_SWAP
+/**
+ * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
+ * @entry: swap entry to be moved
+ * @from: mem_cgroup which the entry is moved from
+ * @to: mem_cgroup which the entry is moved to
+ *
+ * It succeeds only when the swap_cgroup's record for this entry is the same
+ * as the mem_cgroup's id of @from.
+ *
+ * Returns 0 on success, -EINVAL on failure.
+ *
+ * The caller must have charged to @to, IOW, called page_counter_charge() about
+ * both res and memsw, and called css_get().
+ */
+static int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to)
+{
+ unsigned short old_id, new_id;
+
+ old_id = mem_cgroup_id(from);
+ new_id = mem_cgroup_id(to);
+
+ if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
+ mod_memcg_state(from, MEMCG_SWAP, -1);
+ mod_memcg_state(to, MEMCG_SWAP, 1);
+ return 0;
+ }
+ return -EINVAL;
+}
+#else
+static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
+ struct mem_cgroup *from, struct mem_cgroup *to)
+{
+ return -EINVAL;
+}
+#endif
+
+u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return mem_cgroup_from_css(css)->move_charge_at_immigrate;
+}
+
+#ifdef CONFIG_MMU
+int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ pr_warn_once("Cgroup memory moving (move_charge_at_immigrate) is deprecated. "
+ "Please report your usecase to linux-mm@kvack.org if you "
+ "depend on this functionality.\n");
+
+ if (val & ~MOVE_MASK)
+ return -EINVAL;
+
+ /*
+ * No kind of locking is needed in here, because ->can_attach() will
+ * check this value once in the beginning of the process, and then carry
+ * on with stale data. This means that changes to this value will only
+ * affect task migrations starting after the change.
+ */
+ memcg->move_charge_at_immigrate = val;
+ return 0;
+}
+#else
+int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ return -ENOSYS;
+}
+#endif
+
+#ifdef CONFIG_MMU
+/* Handlers for move charge at task migration. */
+static int mem_cgroup_do_precharge(unsigned long count)
+{
+ int ret;
+
+ /* Try a single bulk charge without reclaim first, kswapd may wake */
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count);
+ if (!ret) {
+ mc.precharge += count;
+ return ret;
+ }
+
+ /* Try charges one by one with reclaim, but do not retry */
+ while (count--) {
+ ret = try_charge(mc.to, GFP_KERNEL | __GFP_NORETRY, 1);
+ if (ret)
+ return ret;
+ mc.precharge++;
+ cond_resched();
+ }
+ return 0;
+}
+
+union mc_target {
+ struct folio *folio;
+ swp_entry_t ent;
+};
+
+enum mc_target_type {
+ MC_TARGET_NONE = 0,
+ MC_TARGET_PAGE,
+ MC_TARGET_SWAP,
+ MC_TARGET_DEVICE,
+};
+
+static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent)
+{
+ struct page *page = vm_normal_page(vma, addr, ptent);
+
+ if (!page)
+ return NULL;
+ if (PageAnon(page)) {
+ if (!(mc.flags & MOVE_ANON))
+ return NULL;
+ } else {
+ if (!(mc.flags & MOVE_FILE))
+ return NULL;
+ }
+ get_page(page);
+
+ return page;
+}
+
+#if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE)
+static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
+ pte_t ptent, swp_entry_t *entry)
+{
+ struct page *page = NULL;
+ swp_entry_t ent = pte_to_swp_entry(ptent);
+
+ if (!(mc.flags & MOVE_ANON))
+ return NULL;
+
+ /*
+ * Handle device private pages that are not accessible by the CPU, but
+ * stored as special swap entries in the page table.
+ */
+ if (is_device_private_entry(ent)) {
+ page = pfn_swap_entry_to_page(ent);
+ if (!get_page_unless_zero(page))
+ return NULL;
+ return page;
+ }
+
+ if (non_swap_entry(ent))
+ return NULL;
+
+ /*
+ * Because swap_cache_get_folio() updates some statistics counter,
+ * we call find_get_page() with swapper_space directly.
+ */
+ page = find_get_page(swap_address_space(ent), swap_cache_index(ent));
+ entry->val = ent.val;
+
+ return page;
+}
+#else
+static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
+ pte_t ptent, swp_entry_t *entry)
+{
+ return NULL;
+}
+#endif
+
+static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent)
+{
+ unsigned long index;
+ struct folio *folio;
+
+ if (!vma->vm_file) /* anonymous vma */
+ return NULL;
+ if (!(mc.flags & MOVE_FILE))
+ return NULL;
+
+ /* folio is moved even if it's not RSS of this task(page-faulted). */
+ /* shmem/tmpfs may report page out on swap: account for that too. */
+ index = linear_page_index(vma, addr);
+ folio = filemap_get_incore_folio(vma->vm_file->f_mapping, index);
+ if (IS_ERR(folio))
+ return NULL;
+ return folio_file_page(folio, index);
+}
+
+/**
+ * mem_cgroup_move_account - move account of the folio
+ * @folio: The folio.
+ * @compound: charge the page as compound or small page
+ * @from: mem_cgroup which the folio is moved from.
+ * @to: mem_cgroup which the folio is moved to. @from != @to.
+ *
+ * The folio must be locked and not on the LRU.
+ *
+ * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
+ * from old cgroup.
+ */
+static int mem_cgroup_move_account(struct folio *folio,
+ bool compound,
+ struct mem_cgroup *from,
+ struct mem_cgroup *to)
+{
+ struct lruvec *from_vec, *to_vec;
+ struct pglist_data *pgdat;
+ unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1;
+ int nid, ret;
+
+ VM_BUG_ON(from == to);
+ VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
+ VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
+ VM_BUG_ON(compound && !folio_test_large(folio));
+
+ ret = -EINVAL;
+ if (folio_memcg(folio) != from)
+ goto out;
+
+ pgdat = folio_pgdat(folio);
+ from_vec = mem_cgroup_lruvec(from, pgdat);
+ to_vec = mem_cgroup_lruvec(to, pgdat);
+
+ folio_memcg_lock(folio);
+
+ if (folio_test_anon(folio)) {
+ if (folio_mapped(folio)) {
+ __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages);
+ __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages);
+ if (folio_test_pmd_mappable(folio)) {
+ __mod_lruvec_state(from_vec, NR_ANON_THPS,
+ -nr_pages);
+ __mod_lruvec_state(to_vec, NR_ANON_THPS,
+ nr_pages);
+ }
+ }
+ } else {
+ __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages);
+ __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages);
+
+ if (folio_test_swapbacked(folio)) {
+ __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages);
+ __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages);
+ }
+
+ if (folio_mapped(folio)) {
+ __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
+ __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
+ }
+
+ if (folio_test_dirty(folio)) {
+ struct address_space *mapping = folio_mapping(folio);
+
+ if (mapping_can_writeback(mapping)) {
+ __mod_lruvec_state(from_vec, NR_FILE_DIRTY,
+ -nr_pages);
+ __mod_lruvec_state(to_vec, NR_FILE_DIRTY,
+ nr_pages);
+ }
+ }
+ }
+
+#ifdef CONFIG_SWAP
+ if (folio_test_swapcache(folio)) {
+ __mod_lruvec_state(from_vec, NR_SWAPCACHE, -nr_pages);
+ __mod_lruvec_state(to_vec, NR_SWAPCACHE, nr_pages);
+ }
+#endif
+ if (folio_test_writeback(folio)) {
+ __mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages);
+ __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages);
+ }
+
+ /*
+ * All state has been migrated, let's switch to the new memcg.
+ *
+ * It is safe to change page's memcg here because the page
+ * is referenced, charged, isolated, and locked: we can't race
+ * with (un)charging, migration, LRU putback, or anything else
+ * that would rely on a stable page's memory cgroup.
+ *
+ * Note that folio_memcg_lock is a memcg lock, not a page lock,
+ * to save space. As soon as we switch page's memory cgroup to a
+ * new memcg that isn't locked, the above state can change
+ * concurrently again. Make sure we're truly done with it.
+ */
+ smp_mb();
+
+ css_get(&to->css);
+ css_put(&from->css);
+
+ folio->memcg_data = (unsigned long)to;
+
+ __folio_memcg_unlock(from);
+
+ ret = 0;
+ nid = folio_nid(folio);
+
+ local_irq_disable();
+ mem_cgroup_charge_statistics(to, nr_pages);
+ memcg_check_events(to, nid);
+ mem_cgroup_charge_statistics(from, -nr_pages);
+ memcg_check_events(from, nid);
+ local_irq_enable();
+out:
+ return ret;
+}
+
+/**
+ * get_mctgt_type - get target type of moving charge
+ * @vma: the vma the pte to be checked belongs
+ * @addr: the address corresponding to the pte to be checked
+ * @ptent: the pte to be checked
+ * @target: the pointer the target page or swap ent will be stored(can be NULL)
+ *
+ * Context: Called with pte lock held.
+ * Return:
+ * * MC_TARGET_NONE - If the pte is not a target for move charge.
+ * * MC_TARGET_PAGE - If the page corresponding to this pte is a target for
+ * move charge. If @target is not NULL, the folio is stored in target->folio
+ * with extra refcnt taken (Caller should release it).
+ * * MC_TARGET_SWAP - If the swap entry corresponding to this pte is a
+ * target for charge migration. If @target is not NULL, the entry is
+ * stored in target->ent.
+ * * MC_TARGET_DEVICE - Like MC_TARGET_PAGE but page is device memory and
+ * thus not on the lru. For now such page is charged like a regular page
+ * would be as it is just special memory taking the place of a regular page.
+ * See Documentations/vm/hmm.txt and include/linux/hmm.h
+ */
+static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
+ unsigned long addr, pte_t ptent, union mc_target *target)
+{
+ struct page *page = NULL;
+ struct folio *folio;
+ enum mc_target_type ret = MC_TARGET_NONE;
+ swp_entry_t ent = { .val = 0 };
+
+ if (pte_present(ptent))
+ page = mc_handle_present_pte(vma, addr, ptent);
+ else if (pte_none_mostly(ptent))
+ /*
+ * PTE markers should be treated as a none pte here, separated
+ * from other swap handling below.
+ */
+ page = mc_handle_file_pte(vma, addr, ptent);
+ else if (is_swap_pte(ptent))
+ page = mc_handle_swap_pte(vma, ptent, &ent);
+
+ if (page)
+ folio = page_folio(page);
+ if (target && page) {
+ if (!folio_trylock(folio)) {
+ folio_put(folio);
+ return ret;
+ }
+ /*
+ * page_mapped() must be stable during the move. This
+ * pte is locked, so if it's present, the page cannot
+ * become unmapped. If it isn't, we have only partial
+ * control over the mapped state: the page lock will
+ * prevent new faults against pagecache and swapcache,
+ * so an unmapped page cannot become mapped. However,
+ * if the page is already mapped elsewhere, it can
+ * unmap, and there is nothing we can do about it.
+ * Alas, skip moving the page in this case.
+ */
+ if (!pte_present(ptent) && page_mapped(page)) {
+ folio_unlock(folio);
+ folio_put(folio);
+ return ret;
+ }
+ }
+
+ if (!page && !ent.val)
+ return ret;
+ if (page) {
+ /*
+ * Do only loose check w/o serialization.
+ * mem_cgroup_move_account() checks the page is valid or
+ * not under LRU exclusion.
+ */
+ if (folio_memcg(folio) == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (folio_is_device_private(folio) ||
+ folio_is_device_coherent(folio))
+ ret = MC_TARGET_DEVICE;
+ if (target)
+ target->folio = folio;
+ }
+ if (!ret || !target) {
+ if (target)
+ folio_unlock(folio);
+ folio_put(folio);
+ }
+ }
+ /*
+ * There is a swap entry and a page doesn't exist or isn't charged.
+ * But we cannot move a tail-page in a THP.
+ */
+ if (ent.val && !ret && (!page || !PageTransCompound(page)) &&
+ mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
+ ret = MC_TARGET_SWAP;
+ if (target)
+ target->ent = ent;
+ }
+ return ret;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * We don't consider PMD mapped swapping or file mapped pages because THP does
+ * not support them for now.
+ * Caller should make sure that pmd_trans_huge(pmd) is true.
+ */
+static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ struct page *page = NULL;
+ struct folio *folio;
+ enum mc_target_type ret = MC_TARGET_NONE;
+
+ if (unlikely(is_swap_pmd(pmd))) {
+ VM_BUG_ON(thp_migration_supported() &&
+ !is_pmd_migration_entry(pmd));
+ return ret;
+ }
+ page = pmd_page(pmd);
+ VM_BUG_ON_PAGE(!page || !PageHead(page), page);
+ folio = page_folio(page);
+ if (!(mc.flags & MOVE_ANON))
+ return ret;
+ if (folio_memcg(folio) == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target) {
+ folio_get(folio);
+ if (!folio_trylock(folio)) {
+ folio_put(folio);
+ return MC_TARGET_NONE;
+ }
+ target->folio = folio;
+ }
+ }
+ return ret;
+}
+#else
+static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ return MC_TARGET_NONE;
+}
+#endif
+
+static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->vma;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ ptl = pmd_trans_huge_lock(pmd, vma);
+ if (ptl) {
+ /*
+ * Note their can not be MC_TARGET_DEVICE for now as we do not
+ * support transparent huge page with MEMORY_DEVICE_PRIVATE but
+ * this might change.
+ */
+ if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
+ mc.precharge += HPAGE_PMD_NR;
+ spin_unlock(ptl);
+ return 0;
+ }
+
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ if (!pte)
+ return 0;
+ for (; addr != end; pte++, addr += PAGE_SIZE)
+ if (get_mctgt_type(vma, addr, ptep_get(pte), NULL))
+ mc.precharge++; /* increment precharge temporarily */
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ return 0;
+}
+
+static const struct mm_walk_ops precharge_walk_ops = {
+ .pmd_entry = mem_cgroup_count_precharge_pte_range,
+ .walk_lock = PGWALK_RDLOCK,
+};
+
+static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
+{
+ unsigned long precharge;
+
+ mmap_read_lock(mm);
+ walk_page_range(mm, 0, ULONG_MAX, &precharge_walk_ops, NULL);
+ mmap_read_unlock(mm);
+
+ precharge = mc.precharge;
+ mc.precharge = 0;
+
+ return precharge;
+}
+
+static int mem_cgroup_precharge_mc(struct mm_struct *mm)
+{
+ unsigned long precharge = mem_cgroup_count_precharge(mm);
+
+ VM_BUG_ON(mc.moving_task);
+ mc.moving_task = current;
+ return mem_cgroup_do_precharge(precharge);
+}
+
+/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
+static void __mem_cgroup_clear_mc(void)
+{
+ struct mem_cgroup *from = mc.from;
+ struct mem_cgroup *to = mc.to;
+
+ /* we must uncharge all the leftover precharges from mc.to */
+ if (mc.precharge) {
+ mem_cgroup_cancel_charge(mc.to, mc.precharge);
+ mc.precharge = 0;
+ }
+ /*
+ * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
+ * we must uncharge here.
+ */
+ if (mc.moved_charge) {
+ mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
+ mc.moved_charge = 0;
+ }
+ /* we must fixup refcnts and charges */
+ if (mc.moved_swap) {
+ /* uncharge swap account from the old cgroup */
+ if (!mem_cgroup_is_root(mc.from))
+ page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
+
+ mem_cgroup_id_put_many(mc.from, mc.moved_swap);
+
+ /*
+ * we charged both to->memory and to->memsw, so we
+ * should uncharge to->memory.
+ */
+ if (!mem_cgroup_is_root(mc.to))
+ page_counter_uncharge(&mc.to->memory, mc.moved_swap);
+
+ mc.moved_swap = 0;
+ }
+ memcg_oom_recover(from);
+ memcg_oom_recover(to);
+ wake_up_all(&mc.waitq);
+}
+
+static void mem_cgroup_clear_mc(void)
+{
+ struct mm_struct *mm = mc.mm;
+
+ /*
+ * we must clear moving_task before waking up waiters at the end of
+ * task migration.
+ */
+ mc.moving_task = NULL;
+ __mem_cgroup_clear_mc();
+ spin_lock(&mc.lock);
+ mc.from = NULL;
+ mc.to = NULL;
+ mc.mm = NULL;
+ spin_unlock(&mc.lock);
+
+ mmput(mm);
+}
+
+int mem_cgroup_can_attach(struct cgroup_taskset *tset)
+{
+ struct cgroup_subsys_state *css;
+ struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */
+ struct mem_cgroup *from;
+ struct task_struct *leader, *p;
+ struct mm_struct *mm;
+ unsigned long move_flags;
+ int ret = 0;
+
+ /* charge immigration isn't supported on the default hierarchy */
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ return 0;
+
+ /*
+ * Multi-process migrations only happen on the default hierarchy
+ * where charge immigration is not used. Perform charge
+ * immigration if @tset contains a leader and whine if there are
+ * multiple.
+ */
+ p = NULL;
+ cgroup_taskset_for_each_leader(leader, css, tset) {
+ WARN_ON_ONCE(p);
+ p = leader;
+ memcg = mem_cgroup_from_css(css);
+ }
+ if (!p)
+ return 0;
+
+ /*
+ * We are now committed to this value whatever it is. Changes in this
+ * tunable will only affect upcoming migrations, not the current one.
+ * So we need to save it, and keep it going.
+ */
+ move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
+ if (!move_flags)
+ return 0;
+
+ from = mem_cgroup_from_task(p);
+
+ VM_BUG_ON(from == memcg);
+
+ mm = get_task_mm(p);
+ if (!mm)
+ return 0;
+ /* We move charges only when we move a owner of the mm */
+ if (mm->owner == p) {
+ VM_BUG_ON(mc.from);
+ VM_BUG_ON(mc.to);
+ VM_BUG_ON(mc.precharge);
+ VM_BUG_ON(mc.moved_charge);
+ VM_BUG_ON(mc.moved_swap);
+
+ spin_lock(&mc.lock);
+ mc.mm = mm;
+ mc.from = from;
+ mc.to = memcg;
+ mc.flags = move_flags;
+ spin_unlock(&mc.lock);
+ /* We set mc.moving_task later */
+
+ ret = mem_cgroup_precharge_mc(mm);
+ if (ret)
+ mem_cgroup_clear_mc();
+ } else {
+ mmput(mm);
+ }
+ return ret;
+}
+
+void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
+{
+ if (mc.to)
+ mem_cgroup_clear_mc();
+}
+
+static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ int ret = 0;
+ struct vm_area_struct *vma = walk->vma;
+ pte_t *pte;
+ spinlock_t *ptl;
+ enum mc_target_type target_type;
+ union mc_target target;
+ struct folio *folio;
+
+ ptl = pmd_trans_huge_lock(pmd, vma);
+ if (ptl) {
+ if (mc.precharge < HPAGE_PMD_NR) {
+ spin_unlock(ptl);
+ return 0;
+ }
+ target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
+ if (target_type == MC_TARGET_PAGE) {
+ folio = target.folio;
+ if (folio_isolate_lru(folio)) {
+ if (!mem_cgroup_move_account(folio, true,
+ mc.from, mc.to)) {
+ mc.precharge -= HPAGE_PMD_NR;
+ mc.moved_charge += HPAGE_PMD_NR;
+ }
+ folio_putback_lru(folio);
+ }
+ folio_unlock(folio);
+ folio_put(folio);
+ } else if (target_type == MC_TARGET_DEVICE) {
+ folio = target.folio;
+ if (!mem_cgroup_move_account(folio, true,
+ mc.from, mc.to)) {
+ mc.precharge -= HPAGE_PMD_NR;
+ mc.moved_charge += HPAGE_PMD_NR;
+ }
+ folio_unlock(folio);
+ folio_put(folio);
+ }
+ spin_unlock(ptl);
+ return 0;
+ }
+
+retry:
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ if (!pte)
+ return 0;
+ for (; addr != end; addr += PAGE_SIZE) {
+ pte_t ptent = ptep_get(pte++);
+ bool device = false;
+ swp_entry_t ent;
+
+ if (!mc.precharge)
+ break;
+
+ switch (get_mctgt_type(vma, addr, ptent, &target)) {
+ case MC_TARGET_DEVICE:
+ device = true;
+ fallthrough;
+ case MC_TARGET_PAGE:
+ folio = target.folio;
+ /*
+ * We can have a part of the split pmd here. Moving it
+ * can be done but it would be too convoluted so simply
+ * ignore such a partial THP and keep it in original
+ * memcg. There should be somebody mapping the head.
+ */
+ if (folio_test_large(folio))
+ goto put;
+ if (!device && !folio_isolate_lru(folio))
+ goto put;
+ if (!mem_cgroup_move_account(folio, false,
+ mc.from, mc.to)) {
+ mc.precharge--;
+ /* we uncharge from mc.from later. */
+ mc.moved_charge++;
+ }
+ if (!device)
+ folio_putback_lru(folio);
+put: /* get_mctgt_type() gets & locks the page */
+ folio_unlock(folio);
+ folio_put(folio);
+ break;
+ case MC_TARGET_SWAP:
+ ent = target.ent;
+ if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
+ mc.precharge--;
+ mem_cgroup_id_get_many(mc.to, 1);
+ /* we fixup other refcnts and charges later. */
+ mc.moved_swap++;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+
+ if (addr != end) {
+ /*
+ * We have consumed all precharges we got in can_attach().
+ * We try charge one by one, but don't do any additional
+ * charges to mc.to if we have failed in charge once in attach()
+ * phase.
+ */
+ ret = mem_cgroup_do_precharge(1);
+ if (!ret)
+ goto retry;
+ }
+
+ return ret;
+}
+
+static const struct mm_walk_ops charge_walk_ops = {
+ .pmd_entry = mem_cgroup_move_charge_pte_range,
+ .walk_lock = PGWALK_RDLOCK,
+};
+
+static void mem_cgroup_move_charge(void)
+{
+ lru_add_drain_all();
+ /*
+ * Signal folio_memcg_lock() to take the memcg's move_lock
+ * while we're moving its pages to another memcg. Then wait
+ * for already started RCU-only updates to finish.
+ */
+ atomic_inc(&mc.from->moving_account);
+ synchronize_rcu();
+retry:
+ if (unlikely(!mmap_read_trylock(mc.mm))) {
+ /*
+ * Someone who are holding the mmap_lock might be waiting in
+ * waitq. So we cancel all extra charges, wake up all waiters,
+ * and retry. Because we cancel precharges, we might not be able
+ * to move enough charges, but moving charge is a best-effort
+ * feature anyway, so it wouldn't be a big problem.
+ */
+ __mem_cgroup_clear_mc();
+ cond_resched();
+ goto retry;
+ }
+ /*
+ * When we have consumed all precharges and failed in doing
+ * additional charge, the page walk just aborts.
+ */
+ walk_page_range(mc.mm, 0, ULONG_MAX, &charge_walk_ops, NULL);
+ mmap_read_unlock(mc.mm);
+ atomic_dec(&mc.from->moving_account);
+}
+
+void mem_cgroup_move_task(void)
+{
+ if (mc.to) {
+ mem_cgroup_move_charge();
+ mem_cgroup_clear_mc();
+ }
+}
+
+#else /* !CONFIG_MMU */
+static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
+{
+ return 0;
+}
+static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
+{
+}
+static void mem_cgroup_move_task(void)
+{
+}
+#endif
+
static int __init memcg1_init(void)
{
int node;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index e37bc7e8d9558..55e7c4f90c399 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -11,4 +11,34 @@ static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
WRITE_ONCE(memcg->soft_limit, PAGE_COUNTER_MAX);
}
+void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages);
+void memcg_check_events(struct mem_cgroup *memcg, int nid);
+void memcg_oom_recover(struct mem_cgroup *memcg);
+int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ unsigned int nr_pages);
+
+static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ unsigned int nr_pages)
+{
+ if (mem_cgroup_is_root(memcg))
+ return 0;
+
+ return try_charge_memcg(memcg, gfp_mask, nr_pages);
+}
+
+void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n);
+void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n);
+
+bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg);
+struct cgroup_taskset;
+int mem_cgroup_can_attach(struct cgroup_taskset *tset);
+void mem_cgroup_cancel_attach(struct cgroup_taskset *tset);
+void mem_cgroup_move_task(void);
+
+struct cftype;
+u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
+ struct cftype *cft);
+int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val);
+
#endif /* __MM_MEMCONTROL_V1_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0fbc4e518222e..ba538ab0a80ad 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -28,7 +28,6 @@
#include <linux/page_counter.h>
#include <linux/memcontrol.h>
#include <linux/cgroup.h>
-#include <linux/pagewalk.h>
#include <linux/sched/mm.h>
#include <linux/shmem_fs.h>
#include <linux/hugetlb.h>
@@ -45,7 +44,6 @@
#include <linux/mutex.h>
#include <linux/rbtree.h>
#include <linux/slab.h>
-#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/spinlock.h>
#include <linux/eventfd.h>
@@ -71,7 +69,6 @@
#include <net/sock.h>
#include <net/ip.h>
#include "slab.h"
-#include "swap.h"
#include "memcontrol-v1.h"
#include <linux/uaccess.h>
@@ -158,31 +155,6 @@ struct mem_cgroup_event {
static void mem_cgroup_threshold(struct mem_cgroup *memcg);
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
-/* Stuffs for move charges at task migration. */
-/*
- * Types of charges to be moved.
- */
-#define MOVE_ANON 0x1U
-#define MOVE_FILE 0x2U
-#define MOVE_MASK (MOVE_ANON | MOVE_FILE)
-
-/* "mc" and its members are protected by cgroup_mutex */
-static struct move_charge_struct {
- spinlock_t lock; /* for from, to */
- struct mm_struct *mm;
- struct mem_cgroup *from;
- struct mem_cgroup *to;
- unsigned long flags;
- unsigned long precharge;
- unsigned long moved_charge;
- unsigned long moved_swap;
- struct task_struct *moving_task; /* a task moving charges */
- wait_queue_head_t waitq; /* a waitq for other context */
-} mc = {
- .lock = __SPIN_LOCK_UNLOCKED(mc.lock),
- .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
-};
-
/* for encoding cft->private value on file */
enum res_type {
_MEM,
@@ -955,8 +927,7 @@ static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
return READ_ONCE(memcg->vmstats->events_local[i]);
}
-static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
- int nr_pages)
+void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages)
{
/* pagein of a big page is an event. So, ignore page size */
if (nr_pages > 0)
@@ -998,7 +969,7 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
* Check events in order.
*
*/
-static void memcg_check_events(struct mem_cgroup *memcg, int nid)
+void memcg_check_events(struct mem_cgroup *memcg, int nid)
{
if (IS_ENABLED(CONFIG_PREEMPT_RT))
return;
@@ -1467,51 +1438,6 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
return margin;
}
-/*
- * A routine for checking "mem" is under move_account() or not.
- *
- * Checking a cgroup is mc.from or mc.to or under hierarchy of
- * moving cgroups. This is for waiting at high-memory pressure
- * caused by "move".
- */
-static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
-{
- struct mem_cgroup *from;
- struct mem_cgroup *to;
- bool ret = false;
- /*
- * Unlike task_move routines, we access mc.to, mc.from not under
- * mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
- */
- spin_lock(&mc.lock);
- from = mc.from;
- to = mc.to;
- if (!from)
- goto unlock;
-
- ret = mem_cgroup_is_descendant(from, memcg) ||
- mem_cgroup_is_descendant(to, memcg);
-unlock:
- spin_unlock(&mc.lock);
- return ret;
-}
-
-static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
-{
- if (mc.moving_task && current != mc.moving_task) {
- if (mem_cgroup_under_move(memcg)) {
- DEFINE_WAIT(wait);
- prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
- /* moving charge context might have finished. */
- if (mc.moving_task)
- schedule();
- finish_wait(&mc.waitq, &wait);
- return true;
- }
- }
- return false;
-}
-
struct memory_stat {
const char *name;
unsigned int idx;
@@ -1904,7 +1830,7 @@ static int memcg_oom_wake_function(wait_queue_entry_t *wait,
return autoremove_wake_function(wait, mode, sync, arg);
}
-static void memcg_oom_recover(struct mem_cgroup *memcg)
+void memcg_oom_recover(struct mem_cgroup *memcg)
{
/*
* For the following lockless ->under_oom test, the only required
@@ -2093,87 +2019,6 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
pr_cont(" are going to be killed due to memory.oom.group set\n");
}
-/**
- * folio_memcg_lock - Bind a folio to its memcg.
- * @folio: The folio.
- *
- * This function prevents unlocked LRU folios from being moved to
- * another cgroup.
- *
- * It ensures lifetime of the bound memcg. The caller is responsible
- * for the lifetime of the folio.
- */
-void folio_memcg_lock(struct folio *folio)
-{
- struct mem_cgroup *memcg;
- unsigned long flags;
-
- /*
- * The RCU lock is held throughout the transaction. The fast
- * path can get away without acquiring the memcg->move_lock
- * because page moving starts with an RCU grace period.
- */
- rcu_read_lock();
-
- if (mem_cgroup_disabled())
- return;
-again:
- memcg = folio_memcg(folio);
- if (unlikely(!memcg))
- return;
-
-#ifdef CONFIG_PROVE_LOCKING
- local_irq_save(flags);
- might_lock(&memcg->move_lock);
- local_irq_restore(flags);
-#endif
-
- if (atomic_read(&memcg->moving_account) <= 0)
- return;
-
- spin_lock_irqsave(&memcg->move_lock, flags);
- if (memcg != folio_memcg(folio)) {
- spin_unlock_irqrestore(&memcg->move_lock, flags);
- goto again;
- }
-
- /*
- * When charge migration first begins, we can have multiple
- * critical sections holding the fast-path RCU lock and one
- * holding the slowpath move_lock. Track the task who has the
- * move_lock for folio_memcg_unlock().
- */
- memcg->move_lock_task = current;
- memcg->move_lock_flags = flags;
-}
-
-static void __folio_memcg_unlock(struct mem_cgroup *memcg)
-{
- if (memcg && memcg->move_lock_task == current) {
- unsigned long flags = memcg->move_lock_flags;
-
- memcg->move_lock_task = NULL;
- memcg->move_lock_flags = 0;
-
- spin_unlock_irqrestore(&memcg->move_lock, flags);
- }
-
- rcu_read_unlock();
-}
-
-/**
- * folio_memcg_unlock - Release the binding between a folio and its memcg.
- * @folio: The folio.
- *
- * This releases the binding created by folio_memcg_lock(). This does
- * not change the accounting of this folio to its memcg, but it does
- * permit others to change it.
- */
-void folio_memcg_unlock(struct folio *folio)
-{
- __folio_memcg_unlock(folio_memcg(folio));
-}
-
struct memcg_stock_pcp {
local_lock_t stock_lock;
struct mem_cgroup *cached; /* this never be root cgroup */
@@ -2653,8 +2498,8 @@ void mem_cgroup_handle_over_high(gfp_t gfp_mask)
css_put(&memcg->css);
}
-static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
- unsigned int nr_pages)
+int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
+ unsigned int nr_pages)
{
unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages);
int nr_retries = MAX_RECLAIM_RETRIES;
@@ -2849,15 +2694,6 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
return 0;
}
-static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
- unsigned int nr_pages)
-{
- if (mem_cgroup_is_root(memcg))
- return 0;
-
- return try_charge_memcg(memcg, gfp_mask, nr_pages);
-}
-
/**
* mem_cgroup_cancel_charge() - cancel an uncommitted try_charge() call.
* @memcg: memcg previously charged.
@@ -3597,43 +3433,6 @@ void split_page_memcg(struct page *head, int old_order, int new_order)
css_get_many(&memcg->css, old_nr / new_nr - 1);
}
-#ifdef CONFIG_SWAP
-/**
- * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
- * @entry: swap entry to be moved
- * @from: mem_cgroup which the entry is moved from
- * @to: mem_cgroup which the entry is moved to
- *
- * It succeeds only when the swap_cgroup's record for this entry is the same
- * as the mem_cgroup's id of @from.
- *
- * Returns 0 on success, -EINVAL on failure.
- *
- * The caller must have charged to @to, IOW, called page_counter_charge() about
- * both res and memsw, and called css_get().
- */
-static int mem_cgroup_move_swap_account(swp_entry_t entry,
- struct mem_cgroup *from, struct mem_cgroup *to)
-{
- unsigned short old_id, new_id;
-
- old_id = mem_cgroup_id(from);
- new_id = mem_cgroup_id(to);
-
- if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
- mod_memcg_state(from, MEMCG_SWAP, -1);
- mod_memcg_state(to, MEMCG_SWAP, 1);
- return 0;
- }
- return -EINVAL;
-}
-#else
-static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
- struct mem_cgroup *from, struct mem_cgroup *to)
-{
- return -EINVAL;
-}
-#endif
static DEFINE_MUTEX(memcg_max_mutex);
@@ -4017,42 +3816,6 @@ static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
return nbytes;
}
-static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return mem_cgroup_from_css(css)->move_charge_at_immigrate;
-}
-
-#ifdef CONFIG_MMU
-static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
-
- pr_warn_once("Cgroup memory moving (move_charge_at_immigrate) is deprecated. "
- "Please report your usecase to linux-mm@kvack.org if you "
- "depend on this functionality.\n");
-
- if (val & ~MOVE_MASK)
- return -EINVAL;
-
- /*
- * No kind of locking is needed in here, because ->can_attach() will
- * check this value once in the beginning of the process, and then carry
- * on with stale data. This means that changes to this value will only
- * affect task migrations starting after the change.
- */
- memcg->move_charge_at_immigrate = val;
- return 0;
-}
-#else
-static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val)
-{
- return -ENOSYS;
-}
-#endif
-
#ifdef CONFIG_NUMA
#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
@@ -5263,13 +5026,13 @@ static void mem_cgroup_id_remove(struct mem_cgroup *memcg)
}
}
-static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg,
- unsigned int n)
+void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg,
+ unsigned int n)
{
refcount_add(n, &memcg->id.ref);
}
-static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
+void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
{
if (refcount_sub_and_test(n, &memcg->id.ref)) {
mem_cgroup_id_remove(memcg);
@@ -5749,757 +5512,6 @@ static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu)
atomic64_set(&memcg->vmstats->stats_updates, 0);
}
-#ifdef CONFIG_MMU
-/* Handlers for move charge at task migration. */
-static int mem_cgroup_do_precharge(unsigned long count)
-{
- int ret;
-
- /* Try a single bulk charge without reclaim first, kswapd may wake */
- ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count);
- if (!ret) {
- mc.precharge += count;
- return ret;
- }
-
- /* Try charges one by one with reclaim, but do not retry */
- while (count--) {
- ret = try_charge(mc.to, GFP_KERNEL | __GFP_NORETRY, 1);
- if (ret)
- return ret;
- mc.precharge++;
- cond_resched();
- }
- return 0;
-}
-
-union mc_target {
- struct folio *folio;
- swp_entry_t ent;
-};
-
-enum mc_target_type {
- MC_TARGET_NONE = 0,
- MC_TARGET_PAGE,
- MC_TARGET_SWAP,
- MC_TARGET_DEVICE,
-};
-
-static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
- unsigned long addr, pte_t ptent)
-{
- struct page *page = vm_normal_page(vma, addr, ptent);
-
- if (!page)
- return NULL;
- if (PageAnon(page)) {
- if (!(mc.flags & MOVE_ANON))
- return NULL;
- } else {
- if (!(mc.flags & MOVE_FILE))
- return NULL;
- }
- get_page(page);
-
- return page;
-}
-
-#if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE)
-static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
- pte_t ptent, swp_entry_t *entry)
-{
- struct page *page = NULL;
- swp_entry_t ent = pte_to_swp_entry(ptent);
-
- if (!(mc.flags & MOVE_ANON))
- return NULL;
-
- /*
- * Handle device private pages that are not accessible by the CPU, but
- * stored as special swap entries in the page table.
- */
- if (is_device_private_entry(ent)) {
- page = pfn_swap_entry_to_page(ent);
- if (!get_page_unless_zero(page))
- return NULL;
- return page;
- }
-
- if (non_swap_entry(ent))
- return NULL;
-
- /*
- * Because swap_cache_get_folio() updates some statistics counter,
- * we call find_get_page() with swapper_space directly.
- */
- page = find_get_page(swap_address_space(ent), swap_cache_index(ent));
- entry->val = ent.val;
-
- return page;
-}
-#else
-static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
- pte_t ptent, swp_entry_t *entry)
-{
- return NULL;
-}
-#endif
-
-static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
- unsigned long addr, pte_t ptent)
-{
- unsigned long index;
- struct folio *folio;
-
- if (!vma->vm_file) /* anonymous vma */
- return NULL;
- if (!(mc.flags & MOVE_FILE))
- return NULL;
-
- /* folio is moved even if it's not RSS of this task(page-faulted). */
- /* shmem/tmpfs may report page out on swap: account for that too. */
- index = linear_page_index(vma, addr);
- folio = filemap_get_incore_folio(vma->vm_file->f_mapping, index);
- if (IS_ERR(folio))
- return NULL;
- return folio_file_page(folio, index);
-}
-
-/**
- * mem_cgroup_move_account - move account of the folio
- * @folio: The folio.
- * @compound: charge the page as compound or small page
- * @from: mem_cgroup which the folio is moved from.
- * @to: mem_cgroup which the folio is moved to. @from != @to.
- *
- * The folio must be locked and not on the LRU.
- *
- * This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
- * from old cgroup.
- */
-static int mem_cgroup_move_account(struct folio *folio,
- bool compound,
- struct mem_cgroup *from,
- struct mem_cgroup *to)
-{
- struct lruvec *from_vec, *to_vec;
- struct pglist_data *pgdat;
- unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1;
- int nid, ret;
-
- VM_BUG_ON(from == to);
- VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
- VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
- VM_BUG_ON(compound && !folio_test_large(folio));
-
- ret = -EINVAL;
- if (folio_memcg(folio) != from)
- goto out;
-
- pgdat = folio_pgdat(folio);
- from_vec = mem_cgroup_lruvec(from, pgdat);
- to_vec = mem_cgroup_lruvec(to, pgdat);
-
- folio_memcg_lock(folio);
-
- if (folio_test_anon(folio)) {
- if (folio_mapped(folio)) {
- __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages);
- __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages);
- if (folio_test_pmd_mappable(folio)) {
- __mod_lruvec_state(from_vec, NR_ANON_THPS,
- -nr_pages);
- __mod_lruvec_state(to_vec, NR_ANON_THPS,
- nr_pages);
- }
- }
- } else {
- __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages);
- __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages);
-
- if (folio_test_swapbacked(folio)) {
- __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages);
- __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages);
- }
-
- if (folio_mapped(folio)) {
- __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
- __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
- }
-
- if (folio_test_dirty(folio)) {
- struct address_space *mapping = folio_mapping(folio);
-
- if (mapping_can_writeback(mapping)) {
- __mod_lruvec_state(from_vec, NR_FILE_DIRTY,
- -nr_pages);
- __mod_lruvec_state(to_vec, NR_FILE_DIRTY,
- nr_pages);
- }
- }
- }
-
-#ifdef CONFIG_SWAP
- if (folio_test_swapcache(folio)) {
- __mod_lruvec_state(from_vec, NR_SWAPCACHE, -nr_pages);
- __mod_lruvec_state(to_vec, NR_SWAPCACHE, nr_pages);
- }
-#endif
- if (folio_test_writeback(folio)) {
- __mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages);
- __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages);
- }
-
- /*
- * All state has been migrated, let's switch to the new memcg.
- *
- * It is safe to change page's memcg here because the page
- * is referenced, charged, isolated, and locked: we can't race
- * with (un)charging, migration, LRU putback, or anything else
- * that would rely on a stable page's memory cgroup.
- *
- * Note that folio_memcg_lock is a memcg lock, not a page lock,
- * to save space. As soon as we switch page's memory cgroup to a
- * new memcg that isn't locked, the above state can change
- * concurrently again. Make sure we're truly done with it.
- */
- smp_mb();
-
- css_get(&to->css);
- css_put(&from->css);
-
- folio->memcg_data = (unsigned long)to;
-
- __folio_memcg_unlock(from);
-
- ret = 0;
- nid = folio_nid(folio);
-
- local_irq_disable();
- mem_cgroup_charge_statistics(to, nr_pages);
- memcg_check_events(to, nid);
- mem_cgroup_charge_statistics(from, -nr_pages);
- memcg_check_events(from, nid);
- local_irq_enable();
-out:
- return ret;
-}
-
-/**
- * get_mctgt_type - get target type of moving charge
- * @vma: the vma the pte to be checked belongs
- * @addr: the address corresponding to the pte to be checked
- * @ptent: the pte to be checked
- * @target: the pointer the target page or swap ent will be stored(can be NULL)
- *
- * Context: Called with pte lock held.
- * Return:
- * * MC_TARGET_NONE - If the pte is not a target for move charge.
- * * MC_TARGET_PAGE - If the page corresponding to this pte is a target for
- * move charge. If @target is not NULL, the folio is stored in target->folio
- * with extra refcnt taken (Caller should release it).
- * * MC_TARGET_SWAP - If the swap entry corresponding to this pte is a
- * target for charge migration. If @target is not NULL, the entry is
- * stored in target->ent.
- * * MC_TARGET_DEVICE - Like MC_TARGET_PAGE but page is device memory and
- * thus not on the lru. For now such page is charged like a regular page
- * would be as it is just special memory taking the place of a regular page.
- * See Documentations/vm/hmm.txt and include/linux/hmm.h
- */
-static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
- unsigned long addr, pte_t ptent, union mc_target *target)
-{
- struct page *page = NULL;
- struct folio *folio;
- enum mc_target_type ret = MC_TARGET_NONE;
- swp_entry_t ent = { .val = 0 };
-
- if (pte_present(ptent))
- page = mc_handle_present_pte(vma, addr, ptent);
- else if (pte_none_mostly(ptent))
- /*
- * PTE markers should be treated as a none pte here, separated
- * from other swap handling below.
- */
- page = mc_handle_file_pte(vma, addr, ptent);
- else if (is_swap_pte(ptent))
- page = mc_handle_swap_pte(vma, ptent, &ent);
-
- if (page)
- folio = page_folio(page);
- if (target && page) {
- if (!folio_trylock(folio)) {
- folio_put(folio);
- return ret;
- }
- /*
- * page_mapped() must be stable during the move. This
- * pte is locked, so if it's present, the page cannot
- * become unmapped. If it isn't, we have only partial
- * control over the mapped state: the page lock will
- * prevent new faults against pagecache and swapcache,
- * so an unmapped page cannot become mapped. However,
- * if the page is already mapped elsewhere, it can
- * unmap, and there is nothing we can do about it.
- * Alas, skip moving the page in this case.
- */
- if (!pte_present(ptent) && page_mapped(page)) {
- folio_unlock(folio);
- folio_put(folio);
- return ret;
- }
- }
-
- if (!page && !ent.val)
- return ret;
- if (page) {
- /*
- * Do only loose check w/o serialization.
- * mem_cgroup_move_account() checks the page is valid or
- * not under LRU exclusion.
- */
- if (folio_memcg(folio) == mc.from) {
- ret = MC_TARGET_PAGE;
- if (folio_is_device_private(folio) ||
- folio_is_device_coherent(folio))
- ret = MC_TARGET_DEVICE;
- if (target)
- target->folio = folio;
- }
- if (!ret || !target) {
- if (target)
- folio_unlock(folio);
- folio_put(folio);
- }
- }
- /*
- * There is a swap entry and a page doesn't exist or isn't charged.
- * But we cannot move a tail-page in a THP.
- */
- if (ent.val && !ret && (!page || !PageTransCompound(page)) &&
- mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
- ret = MC_TARGET_SWAP;
- if (target)
- target->ent = ent;
- }
- return ret;
-}
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-/*
- * We don't consider PMD mapped swapping or file mapped pages because THP does
- * not support them for now.
- * Caller should make sure that pmd_trans_huge(pmd) is true.
- */
-static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
- unsigned long addr, pmd_t pmd, union mc_target *target)
-{
- struct page *page = NULL;
- struct folio *folio;
- enum mc_target_type ret = MC_TARGET_NONE;
-
- if (unlikely(is_swap_pmd(pmd))) {
- VM_BUG_ON(thp_migration_supported() &&
- !is_pmd_migration_entry(pmd));
- return ret;
- }
- page = pmd_page(pmd);
- VM_BUG_ON_PAGE(!page || !PageHead(page), page);
- folio = page_folio(page);
- if (!(mc.flags & MOVE_ANON))
- return ret;
- if (folio_memcg(folio) == mc.from) {
- ret = MC_TARGET_PAGE;
- if (target) {
- folio_get(folio);
- if (!folio_trylock(folio)) {
- folio_put(folio);
- return MC_TARGET_NONE;
- }
- target->folio = folio;
- }
- }
- return ret;
-}
-#else
-static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
- unsigned long addr, pmd_t pmd, union mc_target *target)
-{
- return MC_TARGET_NONE;
-}
-#endif
-
-static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
- unsigned long addr, unsigned long end,
- struct mm_walk *walk)
-{
- struct vm_area_struct *vma = walk->vma;
- pte_t *pte;
- spinlock_t *ptl;
-
- ptl = pmd_trans_huge_lock(pmd, vma);
- if (ptl) {
- /*
- * Note their can not be MC_TARGET_DEVICE for now as we do not
- * support transparent huge page with MEMORY_DEVICE_PRIVATE but
- * this might change.
- */
- if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
- mc.precharge += HPAGE_PMD_NR;
- spin_unlock(ptl);
- return 0;
- }
-
- pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
- if (!pte)
- return 0;
- for (; addr != end; pte++, addr += PAGE_SIZE)
- if (get_mctgt_type(vma, addr, ptep_get(pte), NULL))
- mc.precharge++; /* increment precharge temporarily */
- pte_unmap_unlock(pte - 1, ptl);
- cond_resched();
-
- return 0;
-}
-
-static const struct mm_walk_ops precharge_walk_ops = {
- .pmd_entry = mem_cgroup_count_precharge_pte_range,
- .walk_lock = PGWALK_RDLOCK,
-};
-
-static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
-{
- unsigned long precharge;
-
- mmap_read_lock(mm);
- walk_page_range(mm, 0, ULONG_MAX, &precharge_walk_ops, NULL);
- mmap_read_unlock(mm);
-
- precharge = mc.precharge;
- mc.precharge = 0;
-
- return precharge;
-}
-
-static int mem_cgroup_precharge_mc(struct mm_struct *mm)
-{
- unsigned long precharge = mem_cgroup_count_precharge(mm);
-
- VM_BUG_ON(mc.moving_task);
- mc.moving_task = current;
- return mem_cgroup_do_precharge(precharge);
-}
-
-/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
-static void __mem_cgroup_clear_mc(void)
-{
- struct mem_cgroup *from = mc.from;
- struct mem_cgroup *to = mc.to;
-
- /* we must uncharge all the leftover precharges from mc.to */
- if (mc.precharge) {
- mem_cgroup_cancel_charge(mc.to, mc.precharge);
- mc.precharge = 0;
- }
- /*
- * we didn't uncharge from mc.from at mem_cgroup_move_account(), so
- * we must uncharge here.
- */
- if (mc.moved_charge) {
- mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
- mc.moved_charge = 0;
- }
- /* we must fixup refcnts and charges */
- if (mc.moved_swap) {
- /* uncharge swap account from the old cgroup */
- if (!mem_cgroup_is_root(mc.from))
- page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
-
- mem_cgroup_id_put_many(mc.from, mc.moved_swap);
-
- /*
- * we charged both to->memory and to->memsw, so we
- * should uncharge to->memory.
- */
- if (!mem_cgroup_is_root(mc.to))
- page_counter_uncharge(&mc.to->memory, mc.moved_swap);
-
- mc.moved_swap = 0;
- }
- memcg_oom_recover(from);
- memcg_oom_recover(to);
- wake_up_all(&mc.waitq);
-}
-
-static void mem_cgroup_clear_mc(void)
-{
- struct mm_struct *mm = mc.mm;
-
- /*
- * we must clear moving_task before waking up waiters at the end of
- * task migration.
- */
- mc.moving_task = NULL;
- __mem_cgroup_clear_mc();
- spin_lock(&mc.lock);
- mc.from = NULL;
- mc.to = NULL;
- mc.mm = NULL;
- spin_unlock(&mc.lock);
-
- mmput(mm);
-}
-
-static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
-{
- struct cgroup_subsys_state *css;
- struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */
- struct mem_cgroup *from;
- struct task_struct *leader, *p;
- struct mm_struct *mm;
- unsigned long move_flags;
- int ret = 0;
-
- /* charge immigration isn't supported on the default hierarchy */
- if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
- return 0;
-
- /*
- * Multi-process migrations only happen on the default hierarchy
- * where charge immigration is not used. Perform charge
- * immigration if @tset contains a leader and whine if there are
- * multiple.
- */
- p = NULL;
- cgroup_taskset_for_each_leader(leader, css, tset) {
- WARN_ON_ONCE(p);
- p = leader;
- memcg = mem_cgroup_from_css(css);
- }
- if (!p)
- return 0;
-
- /*
- * We are now committed to this value whatever it is. Changes in this
- * tunable will only affect upcoming migrations, not the current one.
- * So we need to save it, and keep it going.
- */
- move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
- if (!move_flags)
- return 0;
-
- from = mem_cgroup_from_task(p);
-
- VM_BUG_ON(from == memcg);
-
- mm = get_task_mm(p);
- if (!mm)
- return 0;
- /* We move charges only when we move a owner of the mm */
- if (mm->owner == p) {
- VM_BUG_ON(mc.from);
- VM_BUG_ON(mc.to);
- VM_BUG_ON(mc.precharge);
- VM_BUG_ON(mc.moved_charge);
- VM_BUG_ON(mc.moved_swap);
-
- spin_lock(&mc.lock);
- mc.mm = mm;
- mc.from = from;
- mc.to = memcg;
- mc.flags = move_flags;
- spin_unlock(&mc.lock);
- /* We set mc.moving_task later */
-
- ret = mem_cgroup_precharge_mc(mm);
- if (ret)
- mem_cgroup_clear_mc();
- } else {
- mmput(mm);
- }
- return ret;
-}
-
-static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
-{
- if (mc.to)
- mem_cgroup_clear_mc();
-}
-
-static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
- unsigned long addr, unsigned long end,
- struct mm_walk *walk)
-{
- int ret = 0;
- struct vm_area_struct *vma = walk->vma;
- pte_t *pte;
- spinlock_t *ptl;
- enum mc_target_type target_type;
- union mc_target target;
- struct folio *folio;
-
- ptl = pmd_trans_huge_lock(pmd, vma);
- if (ptl) {
- if (mc.precharge < HPAGE_PMD_NR) {
- spin_unlock(ptl);
- return 0;
- }
- target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
- if (target_type == MC_TARGET_PAGE) {
- folio = target.folio;
- if (folio_isolate_lru(folio)) {
- if (!mem_cgroup_move_account(folio, true,
- mc.from, mc.to)) {
- mc.precharge -= HPAGE_PMD_NR;
- mc.moved_charge += HPAGE_PMD_NR;
- }
- folio_putback_lru(folio);
- }
- folio_unlock(folio);
- folio_put(folio);
- } else if (target_type == MC_TARGET_DEVICE) {
- folio = target.folio;
- if (!mem_cgroup_move_account(folio, true,
- mc.from, mc.to)) {
- mc.precharge -= HPAGE_PMD_NR;
- mc.moved_charge += HPAGE_PMD_NR;
- }
- folio_unlock(folio);
- folio_put(folio);
- }
- spin_unlock(ptl);
- return 0;
- }
-
-retry:
- pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
- if (!pte)
- return 0;
- for (; addr != end; addr += PAGE_SIZE) {
- pte_t ptent = ptep_get(pte++);
- bool device = false;
- swp_entry_t ent;
-
- if (!mc.precharge)
- break;
-
- switch (get_mctgt_type(vma, addr, ptent, &target)) {
- case MC_TARGET_DEVICE:
- device = true;
- fallthrough;
- case MC_TARGET_PAGE:
- folio = target.folio;
- /*
- * We can have a part of the split pmd here. Moving it
- * can be done but it would be too convoluted so simply
- * ignore such a partial THP and keep it in original
- * memcg. There should be somebody mapping the head.
- */
- if (folio_test_large(folio))
- goto put;
- if (!device && !folio_isolate_lru(folio))
- goto put;
- if (!mem_cgroup_move_account(folio, false,
- mc.from, mc.to)) {
- mc.precharge--;
- /* we uncharge from mc.from later. */
- mc.moved_charge++;
- }
- if (!device)
- folio_putback_lru(folio);
-put: /* get_mctgt_type() gets & locks the page */
- folio_unlock(folio);
- folio_put(folio);
- break;
- case MC_TARGET_SWAP:
- ent = target.ent;
- if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
- mc.precharge--;
- mem_cgroup_id_get_many(mc.to, 1);
- /* we fixup other refcnts and charges later. */
- mc.moved_swap++;
- }
- break;
- default:
- break;
- }
- }
- pte_unmap_unlock(pte - 1, ptl);
- cond_resched();
-
- if (addr != end) {
- /*
- * We have consumed all precharges we got in can_attach().
- * We try charge one by one, but don't do any additional
- * charges to mc.to if we have failed in charge once in attach()
- * phase.
- */
- ret = mem_cgroup_do_precharge(1);
- if (!ret)
- goto retry;
- }
-
- return ret;
-}
-
-static const struct mm_walk_ops charge_walk_ops = {
- .pmd_entry = mem_cgroup_move_charge_pte_range,
- .walk_lock = PGWALK_RDLOCK,
-};
-
-static void mem_cgroup_move_charge(void)
-{
- lru_add_drain_all();
- /*
- * Signal folio_memcg_lock() to take the memcg's move_lock
- * while we're moving its pages to another memcg. Then wait
- * for already started RCU-only updates to finish.
- */
- atomic_inc(&mc.from->moving_account);
- synchronize_rcu();
-retry:
- if (unlikely(!mmap_read_trylock(mc.mm))) {
- /*
- * Someone who are holding the mmap_lock might be waiting in
- * waitq. So we cancel all extra charges, wake up all waiters,
- * and retry. Because we cancel precharges, we might not be able
- * to move enough charges, but moving charge is a best-effort
- * feature anyway, so it wouldn't be a big problem.
- */
- __mem_cgroup_clear_mc();
- cond_resched();
- goto retry;
- }
- /*
- * When we have consumed all precharges and failed in doing
- * additional charge, the page walk just aborts.
- */
- walk_page_range(mc.mm, 0, ULONG_MAX, &charge_walk_ops, NULL);
- mmap_read_unlock(mc.mm);
- atomic_dec(&mc.from->moving_account);
-}
-
-static void mem_cgroup_move_task(void)
-{
- if (mc.to) {
- mem_cgroup_move_charge();
- mem_cgroup_clear_mc();
- }
-}
-
-#else /* !CONFIG_MMU */
-static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
-{
- return 0;
-}
-static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
-{
-}
-static void mem_cgroup_move_task(void)
-{
-}
-#endif
-
#ifdef CONFIG_MEMCG_KMEM
static void mem_cgroup_fork(struct task_struct *task)
{
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 04/14] mm: memcg: move charge migration code to memcontrol-v1.c
2024-05-28 20:20 ` [PATCH v1 04/14] mm: memcg: move charge migration code to memcontrol-v1.c Roman Gushchin
@ 2024-06-01 6:44 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:44 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:56PM GMT, Roman Gushchin wrote:
> Unlike the legacy cgroup v1 memory controller, cgroup v2 memory
> controller doesn't support moving charged pages between cgroups.
>
> It's a fairly large and complicated code which created a number
> of problems in the past. Let's move this code into memcontrol-v1.c.
> It shaves off 1k lines from memcontrol.c. It's also another step
> towards making the legacy memory controller code optionally compiled.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 05/14] mm: memcg: rename charge move-related functions
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (3 preceding siblings ...)
2024-05-28 20:20 ` [PATCH v1 04/14] mm: memcg: move charge migration code to memcontrol-v1.c Roman Gushchin
@ 2024-05-28 20:20 ` Roman Gushchin
2024-06-01 6:45 ` Shakeel Butt
2024-05-28 20:20 ` [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c Roman Gushchin
` (6 subsequent siblings)
11 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:20 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Rename exported function related to the charge move to have
the memcg1_ prefix.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 8 ++++----
mm/memcontrol-v1.h | 8 ++++----
mm/memcontrol.c | 8 ++++----
3 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index f4c8bec5ae1b8..f3ea01a17eea9 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -384,7 +384,7 @@ static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
return ret;
}
-bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
+bool memcg1_wait_acct_move(struct mem_cgroup *memcg)
{
if (mc.moving_task && current != mc.moving_task) {
if (mem_cgroup_under_move(memcg)) {
@@ -1056,7 +1056,7 @@ static void mem_cgroup_clear_mc(void)
mmput(mm);
}
-int mem_cgroup_can_attach(struct cgroup_taskset *tset)
+int memcg1_can_attach(struct cgroup_taskset *tset)
{
struct cgroup_subsys_state *css;
struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */
@@ -1126,7 +1126,7 @@ int mem_cgroup_can_attach(struct cgroup_taskset *tset)
return ret;
}
-void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
+void memcg1_cancel_attach(struct cgroup_taskset *tset)
{
if (mc.to)
mem_cgroup_clear_mc();
@@ -1285,7 +1285,7 @@ static void mem_cgroup_move_charge(void)
atomic_dec(&mc.from->moving_account);
}
-void mem_cgroup_move_task(void)
+void memcg1_move_task(void)
{
if (mc.to) {
mem_cgroup_move_charge();
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 55e7c4f90c399..d377c0be9880b 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -29,11 +29,11 @@ static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n);
void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n);
-bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg);
+bool memcg1_wait_acct_move(struct mem_cgroup *memcg);
struct cgroup_taskset;
-int mem_cgroup_can_attach(struct cgroup_taskset *tset);
-void mem_cgroup_cancel_attach(struct cgroup_taskset *tset);
-void mem_cgroup_move_task(void);
+int memcg1_can_attach(struct cgroup_taskset *tset);
+void memcg1_cancel_attach(struct cgroup_taskset *tset);
+void memcg1_move_task(void);
struct cftype;
u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ba538ab0a80ad..b983cb6d1d228 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2582,7 +2582,7 @@ int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
* At task move, charge accounts can be doubly counted. So, it's
* better to wait until the end of task_move if something is going on.
*/
- if (mem_cgroup_wait_acct_move(mem_over_limit))
+ if (memcg1_wait_acct_move(mem_over_limit))
goto retry;
if (nr_retries--)
@@ -6032,12 +6032,12 @@ struct cgroup_subsys memory_cgrp_subsys = {
.css_free = mem_cgroup_css_free,
.css_reset = mem_cgroup_css_reset,
.css_rstat_flush = mem_cgroup_css_rstat_flush,
- .can_attach = mem_cgroup_can_attach,
+ .can_attach = memcg1_can_attach,
#if defined(CONFIG_LRU_GEN) || defined(CONFIG_MEMCG_KMEM)
.attach = mem_cgroup_attach,
#endif
- .cancel_attach = mem_cgroup_cancel_attach,
- .post_attach = mem_cgroup_move_task,
+ .cancel_attach = memcg1_cancel_attach,
+ .post_attach = memcg1_move_task,
#ifdef CONFIG_MEMCG_KMEM
.fork = mem_cgroup_fork,
.exit = mem_cgroup_exit,
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 05/14] mm: memcg: rename charge move-related functions
2024-05-28 20:20 ` [PATCH v1 05/14] mm: memcg: rename charge move-related functions Roman Gushchin
@ 2024-06-01 6:45 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:45 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:57PM GMT, Roman Gushchin wrote:
> Rename exported function related to the charge move to have
> the memcg1_ prefix.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (4 preceding siblings ...)
2024-05-28 20:20 ` [PATCH v1 05/14] mm: memcg: rename charge move-related functions Roman Gushchin
@ 2024-05-28 20:20 ` Roman Gushchin
2024-06-01 6:33 ` Shakeel Butt
2024-06-01 6:45 ` Shakeel Butt
2024-05-28 20:20 ` [PATCH v1 07/14] mm: memcg: rename memcg_check_events() Roman Gushchin
` (5 subsequent siblings)
11 siblings, 2 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:20 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Cgroup v1's memory controller contains a pretty complicated
event notifications mechanism which is not used on cgroup v2.
Let's move the corresponding code into memcontrol-v1.c.
Please, note, that mem_cgroup_event_ratelimit() remains in
memcontrol.c, otherwise it would require exporting too many
details on memcg stats outside of memcontrol.c.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
include/linux/memcontrol.h | 12 -
mm/memcontrol-v1.c | 653 +++++++++++++++++++++++++++++++++++
mm/memcontrol-v1.h | 51 +++
mm/memcontrol.c | 687 +------------------------------------
4 files changed, 709 insertions(+), 694 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 04f9f7b0e7c2f..394b92b620d9c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -69,18 +69,6 @@ struct mem_cgroup_id {
refcount_t ref;
};
-/*
- * Per memcg event counter is incremented at every pagein/pageout. With THP,
- * it will be incremented by the number of pages. This counter is used
- * to trigger some periodic events. This is straightforward and better
- * than using jiffies etc. to handle periodic memcg event.
- */
-enum mem_cgroup_events_target {
- MEM_CGROUP_TARGET_THRESH,
- MEM_CGROUP_TARGET_SOFTLIMIT,
- MEM_CGROUP_NTARGETS,
-};
-
struct memcg_vmstats_percpu;
struct memcg_vmstats;
struct lruvec_stats_percpu;
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index f3ea01a17eea9..c47ffb6105931 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -6,6 +6,10 @@
#include <linux/pagewalk.h>
#include <linux/backing-dev.h>
#include <linux/swap_cgroup.h>
+#include <linux/eventfd.h>
+#include <linux/poll.h>
+#include <linux/sort.h>
+#include <linux/file.h>
#include "internal.h"
#include "swap.h"
@@ -60,6 +64,54 @@ static struct move_charge_struct {
.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
};
+/* for OOM */
+struct mem_cgroup_eventfd_list {
+ struct list_head list;
+ struct eventfd_ctx *eventfd;
+};
+
+/*
+ * cgroup_event represents events which userspace want to receive.
+ */
+struct mem_cgroup_event {
+ /*
+ * memcg which the event belongs to.
+ */
+ struct mem_cgroup *memcg;
+ /*
+ * eventfd to signal userspace about the event.
+ */
+ struct eventfd_ctx *eventfd;
+ /*
+ * Each of these stored in a list by the cgroup.
+ */
+ struct list_head list;
+ /*
+ * register_event() callback will be used to add new userspace
+ * waiter for changes related to this event. Use eventfd_signal()
+ * on eventfd to send notification to userspace.
+ */
+ int (*register_event)(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args);
+ /*
+ * unregister_event() callback will be called when userspace closes
+ * the eventfd or on cgroup removing. This callback must be set,
+ * if you want provide notification functionality.
+ */
+ void (*unregister_event)(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd);
+ /*
+ * All fields below needed to unregister event when
+ * userspace closes eventfd.
+ */
+ poll_table pt;
+ wait_queue_head_t *wqh;
+ wait_queue_entry_t wait;
+ struct work_struct remove;
+};
+
+extern spinlock_t memcg_oom_lock;
+
static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
struct mem_cgroup_tree_per_node *mctz,
unsigned long new_usage_in_excess)
@@ -1306,6 +1358,607 @@ static void mem_cgroup_move_task(void)
}
#endif
+static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
+{
+ struct mem_cgroup_threshold_ary *t;
+ unsigned long usage;
+ int i;
+
+ rcu_read_lock();
+ if (!swap)
+ t = rcu_dereference(memcg->thresholds.primary);
+ else
+ t = rcu_dereference(memcg->memsw_thresholds.primary);
+
+ if (!t)
+ goto unlock;
+
+ usage = mem_cgroup_usage(memcg, swap);
+
+ /*
+ * current_threshold points to threshold just below or equal to usage.
+ * If it's not true, a threshold was crossed after last
+ * call of __mem_cgroup_threshold().
+ */
+ i = t->current_threshold;
+
+ /*
+ * Iterate backward over array of thresholds starting from
+ * current_threshold and check if a threshold is crossed.
+ * If none of thresholds below usage is crossed, we read
+ * only one element of the array here.
+ */
+ for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
+ eventfd_signal(t->entries[i].eventfd);
+
+ /* i = current_threshold + 1 */
+ i++;
+
+ /*
+ * Iterate forward over array of thresholds starting from
+ * current_threshold+1 and check if a threshold is crossed.
+ * If none of thresholds above usage is crossed, we read
+ * only one element of the array here.
+ */
+ for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
+ eventfd_signal(t->entries[i].eventfd);
+
+ /* Update current_threshold */
+ t->current_threshold = i - 1;
+unlock:
+ rcu_read_unlock();
+}
+
+static void mem_cgroup_threshold(struct mem_cgroup *memcg)
+{
+ while (memcg) {
+ __mem_cgroup_threshold(memcg, false);
+ if (do_memsw_account())
+ __mem_cgroup_threshold(memcg, true);
+
+ memcg = parent_mem_cgroup(memcg);
+ }
+}
+
+/*
+ * Check events in order.
+ *
+ */
+void memcg_check_events(struct mem_cgroup *memcg, int nid)
+{
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ return;
+
+ /* threshold event is triggered in finer grain than soft limit */
+ if (unlikely(mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_THRESH))) {
+ bool do_softlimit;
+
+ do_softlimit = mem_cgroup_event_ratelimit(memcg,
+ MEM_CGROUP_TARGET_SOFTLIMIT);
+ mem_cgroup_threshold(memcg);
+ if (unlikely(do_softlimit))
+ memcg1_update_tree(memcg, nid);
+ }
+}
+
+static int compare_thresholds(const void *a, const void *b)
+{
+ const struct mem_cgroup_threshold *_a = a;
+ const struct mem_cgroup_threshold *_b = b;
+
+ if (_a->threshold > _b->threshold)
+ return 1;
+
+ if (_a->threshold < _b->threshold)
+ return -1;
+
+ return 0;
+}
+
+static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_eventfd_list *ev;
+
+ spin_lock(&memcg_oom_lock);
+
+ list_for_each_entry(ev, &memcg->oom_notify, list)
+ eventfd_signal(ev->eventfd);
+
+ spin_unlock(&memcg_oom_lock);
+ return 0;
+}
+
+void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg)
+ mem_cgroup_oom_notify_cb(iter);
+}
+
+static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args, enum res_type type)
+{
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
+ unsigned long threshold;
+ unsigned long usage;
+ int i, size, ret;
+
+ ret = page_counter_memparse(args, "-1", &threshold);
+ if (ret)
+ return ret;
+
+ mutex_lock(&memcg->thresholds_lock);
+
+ if (type == _MEM) {
+ thresholds = &memcg->thresholds;
+ usage = mem_cgroup_usage(memcg, false);
+ } else if (type == _MEMSWAP) {
+ thresholds = &memcg->memsw_thresholds;
+ usage = mem_cgroup_usage(memcg, true);
+ } else
+ BUG();
+
+ /* Check if a threshold crossed before adding a new one */
+ if (thresholds->primary)
+ __mem_cgroup_threshold(memcg, type == _MEMSWAP);
+
+ size = thresholds->primary ? thresholds->primary->size + 1 : 1;
+
+ /* Allocate memory for new array of thresholds */
+ new = kmalloc(struct_size(new, entries, size), GFP_KERNEL);
+ if (!new) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ new->size = size;
+
+ /* Copy thresholds (if any) to new array */
+ if (thresholds->primary)
+ memcpy(new->entries, thresholds->primary->entries,
+ flex_array_size(new, entries, size - 1));
+
+ /* Add new threshold */
+ new->entries[size - 1].eventfd = eventfd;
+ new->entries[size - 1].threshold = threshold;
+
+ /* Sort thresholds. Registering of new threshold isn't time-critical */
+ sort(new->entries, size, sizeof(*new->entries),
+ compare_thresholds, NULL);
+
+ /* Find current threshold */
+ new->current_threshold = -1;
+ for (i = 0; i < size; i++) {
+ if (new->entries[i].threshold <= usage) {
+ /*
+ * new->current_threshold will not be used until
+ * rcu_assign_pointer(), so it's safe to increment
+ * it here.
+ */
+ ++new->current_threshold;
+ } else
+ break;
+ }
+
+ /* Free old spare buffer and save old primary buffer as spare */
+ kfree(thresholds->spare);
+ thresholds->spare = thresholds->primary;
+
+ rcu_assign_pointer(thresholds->primary, new);
+
+ /* To be sure that nobody uses thresholds */
+ synchronize_rcu();
+
+unlock:
+ mutex_unlock(&memcg->thresholds_lock);
+
+ return ret;
+}
+
+static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
+}
+
+static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
+}
+
+static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, enum res_type type)
+{
+ struct mem_cgroup_thresholds *thresholds;
+ struct mem_cgroup_threshold_ary *new;
+ unsigned long usage;
+ int i, j, size, entries;
+
+ mutex_lock(&memcg->thresholds_lock);
+
+ if (type == _MEM) {
+ thresholds = &memcg->thresholds;
+ usage = mem_cgroup_usage(memcg, false);
+ } else if (type == _MEMSWAP) {
+ thresholds = &memcg->memsw_thresholds;
+ usage = mem_cgroup_usage(memcg, true);
+ } else
+ BUG();
+
+ if (!thresholds->primary)
+ goto unlock;
+
+ /* Check if a threshold crossed before removing */
+ __mem_cgroup_threshold(memcg, type == _MEMSWAP);
+
+ /* Calculate new number of threshold */
+ size = entries = 0;
+ for (i = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd != eventfd)
+ size++;
+ else
+ entries++;
+ }
+
+ new = thresholds->spare;
+
+ /* If no items related to eventfd have been cleared, nothing to do */
+ if (!entries)
+ goto unlock;
+
+ /* Set thresholds array to NULL if we don't have thresholds */
+ if (!size) {
+ kfree(new);
+ new = NULL;
+ goto swap_buffers;
+ }
+
+ new->size = size;
+
+ /* Copy thresholds and find current threshold */
+ new->current_threshold = -1;
+ for (i = 0, j = 0; i < thresholds->primary->size; i++) {
+ if (thresholds->primary->entries[i].eventfd == eventfd)
+ continue;
+
+ new->entries[j] = thresholds->primary->entries[i];
+ if (new->entries[j].threshold <= usage) {
+ /*
+ * new->current_threshold will not be used
+ * until rcu_assign_pointer(), so it's safe to increment
+ * it here.
+ */
+ ++new->current_threshold;
+ }
+ j++;
+ }
+
+swap_buffers:
+ /* Swap primary and spare array */
+ thresholds->spare = thresholds->primary;
+
+ rcu_assign_pointer(thresholds->primary, new);
+
+ /* To be sure that nobody uses thresholds */
+ synchronize_rcu();
+
+ /* If all events are unregistered, free the spare array */
+ if (!new) {
+ kfree(thresholds->spare);
+ thresholds->spare = NULL;
+ }
+unlock:
+ mutex_unlock(&memcg->thresholds_lock);
+}
+
+static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
+}
+
+static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
+}
+
+static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ struct mem_cgroup_eventfd_list *event;
+
+ event = kmalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ spin_lock(&memcg_oom_lock);
+
+ event->eventfd = eventfd;
+ list_add(&event->list, &memcg->oom_notify);
+
+ /* already in OOM ? */
+ if (memcg->under_oom)
+ eventfd_signal(eventfd);
+ spin_unlock(&memcg_oom_lock);
+
+ return 0;
+}
+
+static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ struct mem_cgroup_eventfd_list *ev, *tmp;
+
+ spin_lock(&memcg_oom_lock);
+
+ list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
+ if (ev->eventfd == eventfd) {
+ list_del(&ev->list);
+ kfree(ev);
+ }
+ }
+
+ spin_unlock(&memcg_oom_lock);
+}
+
+/*
+ * DO NOT USE IN NEW FILES.
+ *
+ * "cgroup.event_control" implementation.
+ *
+ * This is way over-engineered. It tries to support fully configurable
+ * events for each user. Such level of flexibility is completely
+ * unnecessary especially in the light of the planned unified hierarchy.
+ *
+ * Please deprecate this and replace with something simpler if at all
+ * possible.
+ */
+
+/*
+ * Unregister event and free resources.
+ *
+ * Gets called from workqueue.
+ */
+static void memcg_event_remove(struct work_struct *work)
+{
+ struct mem_cgroup_event *event =
+ container_of(work, struct mem_cgroup_event, remove);
+ struct mem_cgroup *memcg = event->memcg;
+
+ remove_wait_queue(event->wqh, &event->wait);
+
+ event->unregister_event(memcg, event->eventfd);
+
+ /* Notify userspace the event is going away. */
+ eventfd_signal(event->eventfd);
+
+ eventfd_ctx_put(event->eventfd);
+ kfree(event);
+ css_put(&memcg->css);
+}
+
+/*
+ * Gets called on EPOLLHUP on eventfd when user closes it.
+ *
+ * Called with wqh->lock held and interrupts disabled.
+ */
+static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode,
+ int sync, void *key)
+{
+ struct mem_cgroup_event *event =
+ container_of(wait, struct mem_cgroup_event, wait);
+ struct mem_cgroup *memcg = event->memcg;
+ __poll_t flags = key_to_poll(key);
+
+ if (flags & EPOLLHUP) {
+ /*
+ * If the event has been detached at cgroup removal, we
+ * can simply return knowing the other side will cleanup
+ * for us.
+ *
+ * We can't race against event freeing since the other
+ * side will require wqh->lock via remove_wait_queue(),
+ * which we hold.
+ */
+ spin_lock(&memcg->event_list_lock);
+ if (!list_empty(&event->list)) {
+ list_del_init(&event->list);
+ /*
+ * We are in atomic context, but cgroup_event_remove()
+ * may sleep, so we have to call it in workqueue.
+ */
+ schedule_work(&event->remove);
+ }
+ spin_unlock(&memcg->event_list_lock);
+ }
+
+ return 0;
+}
+
+static void memcg_event_ptable_queue_proc(struct file *file,
+ wait_queue_head_t *wqh, poll_table *pt)
+{
+ struct mem_cgroup_event *event =
+ container_of(pt, struct mem_cgroup_event, pt);
+
+ event->wqh = wqh;
+ add_wait_queue(wqh, &event->wait);
+}
+
+/*
+ * DO NOT USE IN NEW FILES.
+ *
+ * Parse input and register new cgroup event handler.
+ *
+ * Input must be in format '<event_fd> <control_fd> <args>'.
+ * Interpretation of args is defined by control file implementation.
+ */
+ssize_t memcg_write_event_control(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct cgroup_subsys_state *css = of_css(of);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup_event *event;
+ struct cgroup_subsys_state *cfile_css;
+ unsigned int efd, cfd;
+ struct fd efile;
+ struct fd cfile;
+ struct dentry *cdentry;
+ const char *name;
+ char *endp;
+ int ret;
+
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ return -EOPNOTSUPP;
+
+ buf = strstrip(buf);
+
+ efd = simple_strtoul(buf, &endp, 10);
+ if (*endp != ' ')
+ return -EINVAL;
+ buf = endp + 1;
+
+ cfd = simple_strtoul(buf, &endp, 10);
+ if ((*endp != ' ') && (*endp != '\0'))
+ return -EINVAL;
+ buf = endp + 1;
+
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ event->memcg = memcg;
+ INIT_LIST_HEAD(&event->list);
+ init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
+ init_waitqueue_func_entry(&event->wait, memcg_event_wake);
+ INIT_WORK(&event->remove, memcg_event_remove);
+
+ efile = fdget(efd);
+ if (!efile.file) {
+ ret = -EBADF;
+ goto out_kfree;
+ }
+
+ event->eventfd = eventfd_ctx_fileget(efile.file);
+ if (IS_ERR(event->eventfd)) {
+ ret = PTR_ERR(event->eventfd);
+ goto out_put_efile;
+ }
+
+ cfile = fdget(cfd);
+ if (!cfile.file) {
+ ret = -EBADF;
+ goto out_put_eventfd;
+ }
+
+ /* the process need read permission on control file */
+ /* AV: shouldn't we check that it's been opened for read instead? */
+ ret = file_permission(cfile.file, MAY_READ);
+ if (ret < 0)
+ goto out_put_cfile;
+
+ /*
+ * The control file must be a regular cgroup1 file. As a regular cgroup
+ * file can't be renamed, it's safe to access its name afterwards.
+ */
+ cdentry = cfile.file->f_path.dentry;
+ if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) {
+ ret = -EINVAL;
+ goto out_put_cfile;
+ }
+
+ /*
+ * Determine the event callbacks and set them in @event. This used
+ * to be done via struct cftype but cgroup core no longer knows
+ * about these events. The following is crude but the whole thing
+ * is for compatibility anyway.
+ *
+ * DO NOT ADD NEW FILES.
+ */
+ name = cdentry->d_name.name;
+
+ if (!strcmp(name, "memory.usage_in_bytes")) {
+ event->register_event = mem_cgroup_usage_register_event;
+ event->unregister_event = mem_cgroup_usage_unregister_event;
+ } else if (!strcmp(name, "memory.oom_control")) {
+ event->register_event = mem_cgroup_oom_register_event;
+ event->unregister_event = mem_cgroup_oom_unregister_event;
+ } else if (!strcmp(name, "memory.pressure_level")) {
+ event->register_event = vmpressure_register_event;
+ event->unregister_event = vmpressure_unregister_event;
+ } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
+ event->register_event = memsw_cgroup_usage_register_event;
+ event->unregister_event = memsw_cgroup_usage_unregister_event;
+ } else {
+ ret = -EINVAL;
+ goto out_put_cfile;
+ }
+
+ /*
+ * Verify @cfile should belong to @css. Also, remaining events are
+ * automatically removed on cgroup destruction but the removal is
+ * asynchronous, so take an extra ref on @css.
+ */
+ cfile_css = css_tryget_online_from_dir(cdentry->d_parent,
+ &memory_cgrp_subsys);
+ ret = -EINVAL;
+ if (IS_ERR(cfile_css))
+ goto out_put_cfile;
+ if (cfile_css != css) {
+ css_put(cfile_css);
+ goto out_put_cfile;
+ }
+
+ ret = event->register_event(memcg, event->eventfd, buf);
+ if (ret)
+ goto out_put_css;
+
+ vfs_poll(efile.file, &event->pt);
+
+ spin_lock_irq(&memcg->event_list_lock);
+ list_add(&event->list, &memcg->event_list);
+ spin_unlock_irq(&memcg->event_list_lock);
+
+ fdput(cfile);
+ fdput(efile);
+
+ return nbytes;
+
+out_put_css:
+ css_put(css);
+out_put_cfile:
+ fdput(cfile);
+out_put_eventfd:
+ eventfd_ctx_put(event->eventfd);
+out_put_efile:
+ fdput(efile);
+out_kfree:
+ kfree(event);
+
+ return ret;
+}
+
+void memcg1_css_offline(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_event *event, *tmp;
+
+ /*
+ * Unregister events and notify userspace.
+ * Notify userspace about cgroup removing only after rmdir of cgroup
+ * directory to avoid race between userspace and kernelspace.
+ */
+ spin_lock_irq(&memcg->event_list_lock);
+ list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
+ list_del_init(&event->list);
+ schedule_work(&event->remove);
+ }
+ spin_unlock_irq(&memcg->event_list_lock);
+}
+
static int __init memcg1_init(void)
{
int node;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index d377c0be9880b..524a2c76ffc97 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -41,4 +41,55 @@ u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
struct cftype *cft, u64 val);
+/*
+ * Per memcg event counter is incremented at every pagein/pageout. With THP,
+ * it will be incremented by the number of pages. This counter is used
+ * to trigger some periodic events. This is straightforward and better
+ * than using jiffies etc. to handle periodic memcg event.
+ */
+enum mem_cgroup_events_target {
+ MEM_CGROUP_TARGET_THRESH,
+ MEM_CGROUP_TARGET_SOFTLIMIT,
+ MEM_CGROUP_NTARGETS,
+};
+
+/* Whether legacy memory+swap accounting is active */
+static bool do_memsw_account(void)
+{
+ return !cgroup_subsys_on_dfl(memory_cgrp_subsys);
+}
+
+/*
+ * Iteration constructs for visiting all cgroups (under a tree). If
+ * loops are exited prematurely (break), mem_cgroup_iter_break() must
+ * be used for reference counting.
+ */
+#define for_each_mem_cgroup_tree(iter, root) \
+ for (iter = mem_cgroup_iter(root, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(root, iter, NULL))
+
+#define for_each_mem_cgroup(iter) \
+ for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
+ iter != NULL; \
+ iter = mem_cgroup_iter(NULL, iter, NULL))
+
+void memcg1_css_offline(struct mem_cgroup *memcg);
+
+/* for encoding cft->private value on file */
+enum res_type {
+ _MEM,
+ _MEMSWAP,
+ _KMEM,
+ _TCP,
+};
+
+bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_target target);
+unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap);
+void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
+ssize_t memcg_write_event_control(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
+
+
#endif /* __MM_MEMCONTROL_V1_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b983cb6d1d228..6bc9009bee517 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -46,9 +46,6 @@
#include <linux/slab.h>
#include <linux/swapops.h>
#include <linux/spinlock.h>
-#include <linux/eventfd.h>
-#include <linux/poll.h>
-#include <linux/sort.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/parser.h>
@@ -59,7 +56,6 @@
#include <linux/cpu.h>
#include <linux/oom.h>
#include <linux/lockdep.h>
-#include <linux/file.h>
#include <linux/resume_user_mode.h>
#include <linux/psi.h>
#include <linux/seq_buf.h>
@@ -97,91 +93,13 @@ static bool cgroup_memory_nobpf __ro_after_init;
static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq);
#endif
-/* Whether legacy memory+swap accounting is active */
-static bool do_memsw_account(void)
-{
- return !cgroup_subsys_on_dfl(memory_cgrp_subsys);
-}
-
#define THRESHOLDS_EVENTS_TARGET 128
#define SOFTLIMIT_EVENTS_TARGET 1024
-/* for OOM */
-struct mem_cgroup_eventfd_list {
- struct list_head list;
- struct eventfd_ctx *eventfd;
-};
-
-/*
- * cgroup_event represents events which userspace want to receive.
- */
-struct mem_cgroup_event {
- /*
- * memcg which the event belongs to.
- */
- struct mem_cgroup *memcg;
- /*
- * eventfd to signal userspace about the event.
- */
- struct eventfd_ctx *eventfd;
- /*
- * Each of these stored in a list by the cgroup.
- */
- struct list_head list;
- /*
- * register_event() callback will be used to add new userspace
- * waiter for changes related to this event. Use eventfd_signal()
- * on eventfd to send notification to userspace.
- */
- int (*register_event)(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd, const char *args);
- /*
- * unregister_event() callback will be called when userspace closes
- * the eventfd or on cgroup removing. This callback must be set,
- * if you want provide notification functionality.
- */
- void (*unregister_event)(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd);
- /*
- * All fields below needed to unregister event when
- * userspace closes eventfd.
- */
- poll_table pt;
- wait_queue_head_t *wqh;
- wait_queue_entry_t wait;
- struct work_struct remove;
-};
-
-static void mem_cgroup_threshold(struct mem_cgroup *memcg);
-static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
-
-/* for encoding cft->private value on file */
-enum res_type {
- _MEM,
- _MEMSWAP,
- _KMEM,
- _TCP,
-};
-
#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
#define MEMFILE_ATTR(val) ((val) & 0xffff)
-/*
- * Iteration constructs for visiting all cgroups (under a tree). If
- * loops are exited prematurely (break), mem_cgroup_iter_break() must
- * be used for reference counting.
- */
-#define for_each_mem_cgroup_tree(iter, root) \
- for (iter = mem_cgroup_iter(root, NULL, NULL); \
- iter != NULL; \
- iter = mem_cgroup_iter(root, iter, NULL))
-
-#define for_each_mem_cgroup(iter) \
- for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
- iter != NULL; \
- iter = mem_cgroup_iter(NULL, iter, NULL))
-
static inline bool task_is_dying(void)
{
return tsk_is_oom_victim(current) || fatal_signal_pending(current) ||
@@ -940,8 +858,8 @@ void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages)
__this_cpu_add(memcg->vmstats_percpu->nr_page_events, nr_pages);
}
-static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
- enum mem_cgroup_events_target target)
+bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
+ enum mem_cgroup_events_target target)
{
unsigned long val, next;
@@ -965,28 +883,6 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
return false;
}
-/*
- * Check events in order.
- *
- */
-void memcg_check_events(struct mem_cgroup *memcg, int nid)
-{
- if (IS_ENABLED(CONFIG_PREEMPT_RT))
- return;
-
- /* threshold event is triggered in finer grain than soft limit */
- if (unlikely(mem_cgroup_event_ratelimit(memcg,
- MEM_CGROUP_TARGET_THRESH))) {
- bool do_softlimit;
-
- do_softlimit = mem_cgroup_event_ratelimit(memcg,
- MEM_CGROUP_TARGET_SOFTLIMIT);
- mem_cgroup_threshold(memcg);
- if (unlikely(do_softlimit))
- memcg1_update_tree(memcg, nid);
- }
-}
-
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
{
/*
@@ -1726,7 +1622,7 @@ static struct lockdep_map memcg_oom_lock_dep_map = {
};
#endif
-static DEFINE_SPINLOCK(memcg_oom_lock);
+DEFINE_SPINLOCK(memcg_oom_lock);
/*
* Check OOM-Killer is already running under our hierarchy.
@@ -3547,7 +3443,7 @@ static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
return -EINVAL;
}
-static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
+unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
{
unsigned long val;
@@ -4048,331 +3944,6 @@ static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
return 0;
}
-static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
-{
- struct mem_cgroup_threshold_ary *t;
- unsigned long usage;
- int i;
-
- rcu_read_lock();
- if (!swap)
- t = rcu_dereference(memcg->thresholds.primary);
- else
- t = rcu_dereference(memcg->memsw_thresholds.primary);
-
- if (!t)
- goto unlock;
-
- usage = mem_cgroup_usage(memcg, swap);
-
- /*
- * current_threshold points to threshold just below or equal to usage.
- * If it's not true, a threshold was crossed after last
- * call of __mem_cgroup_threshold().
- */
- i = t->current_threshold;
-
- /*
- * Iterate backward over array of thresholds starting from
- * current_threshold and check if a threshold is crossed.
- * If none of thresholds below usage is crossed, we read
- * only one element of the array here.
- */
- for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
- eventfd_signal(t->entries[i].eventfd);
-
- /* i = current_threshold + 1 */
- i++;
-
- /*
- * Iterate forward over array of thresholds starting from
- * current_threshold+1 and check if a threshold is crossed.
- * If none of thresholds above usage is crossed, we read
- * only one element of the array here.
- */
- for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
- eventfd_signal(t->entries[i].eventfd);
-
- /* Update current_threshold */
- t->current_threshold = i - 1;
-unlock:
- rcu_read_unlock();
-}
-
-static void mem_cgroup_threshold(struct mem_cgroup *memcg)
-{
- while (memcg) {
- __mem_cgroup_threshold(memcg, false);
- if (do_memsw_account())
- __mem_cgroup_threshold(memcg, true);
-
- memcg = parent_mem_cgroup(memcg);
- }
-}
-
-static int compare_thresholds(const void *a, const void *b)
-{
- const struct mem_cgroup_threshold *_a = a;
- const struct mem_cgroup_threshold *_b = b;
-
- if (_a->threshold > _b->threshold)
- return 1;
-
- if (_a->threshold < _b->threshold)
- return -1;
-
- return 0;
-}
-
-static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
-{
- struct mem_cgroup_eventfd_list *ev;
-
- spin_lock(&memcg_oom_lock);
-
- list_for_each_entry(ev, &memcg->oom_notify, list)
- eventfd_signal(ev->eventfd);
-
- spin_unlock(&memcg_oom_lock);
- return 0;
-}
-
-static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
-{
- struct mem_cgroup *iter;
-
- for_each_mem_cgroup_tree(iter, memcg)
- mem_cgroup_oom_notify_cb(iter);
-}
-
-static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd, const char *args, enum res_type type)
-{
- struct mem_cgroup_thresholds *thresholds;
- struct mem_cgroup_threshold_ary *new;
- unsigned long threshold;
- unsigned long usage;
- int i, size, ret;
-
- ret = page_counter_memparse(args, "-1", &threshold);
- if (ret)
- return ret;
-
- mutex_lock(&memcg->thresholds_lock);
-
- if (type == _MEM) {
- thresholds = &memcg->thresholds;
- usage = mem_cgroup_usage(memcg, false);
- } else if (type == _MEMSWAP) {
- thresholds = &memcg->memsw_thresholds;
- usage = mem_cgroup_usage(memcg, true);
- } else
- BUG();
-
- /* Check if a threshold crossed before adding a new one */
- if (thresholds->primary)
- __mem_cgroup_threshold(memcg, type == _MEMSWAP);
-
- size = thresholds->primary ? thresholds->primary->size + 1 : 1;
-
- /* Allocate memory for new array of thresholds */
- new = kmalloc(struct_size(new, entries, size), GFP_KERNEL);
- if (!new) {
- ret = -ENOMEM;
- goto unlock;
- }
- new->size = size;
-
- /* Copy thresholds (if any) to new array */
- if (thresholds->primary)
- memcpy(new->entries, thresholds->primary->entries,
- flex_array_size(new, entries, size - 1));
-
- /* Add new threshold */
- new->entries[size - 1].eventfd = eventfd;
- new->entries[size - 1].threshold = threshold;
-
- /* Sort thresholds. Registering of new threshold isn't time-critical */
- sort(new->entries, size, sizeof(*new->entries),
- compare_thresholds, NULL);
-
- /* Find current threshold */
- new->current_threshold = -1;
- for (i = 0; i < size; i++) {
- if (new->entries[i].threshold <= usage) {
- /*
- * new->current_threshold will not be used until
- * rcu_assign_pointer(), so it's safe to increment
- * it here.
- */
- ++new->current_threshold;
- } else
- break;
- }
-
- /* Free old spare buffer and save old primary buffer as spare */
- kfree(thresholds->spare);
- thresholds->spare = thresholds->primary;
-
- rcu_assign_pointer(thresholds->primary, new);
-
- /* To be sure that nobody uses thresholds */
- synchronize_rcu();
-
-unlock:
- mutex_unlock(&memcg->thresholds_lock);
-
- return ret;
-}
-
-static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd, const char *args)
-{
- return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
-}
-
-static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd, const char *args)
-{
- return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
-}
-
-static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd, enum res_type type)
-{
- struct mem_cgroup_thresholds *thresholds;
- struct mem_cgroup_threshold_ary *new;
- unsigned long usage;
- int i, j, size, entries;
-
- mutex_lock(&memcg->thresholds_lock);
-
- if (type == _MEM) {
- thresholds = &memcg->thresholds;
- usage = mem_cgroup_usage(memcg, false);
- } else if (type == _MEMSWAP) {
- thresholds = &memcg->memsw_thresholds;
- usage = mem_cgroup_usage(memcg, true);
- } else
- BUG();
-
- if (!thresholds->primary)
- goto unlock;
-
- /* Check if a threshold crossed before removing */
- __mem_cgroup_threshold(memcg, type == _MEMSWAP);
-
- /* Calculate new number of threshold */
- size = entries = 0;
- for (i = 0; i < thresholds->primary->size; i++) {
- if (thresholds->primary->entries[i].eventfd != eventfd)
- size++;
- else
- entries++;
- }
-
- new = thresholds->spare;
-
- /* If no items related to eventfd have been cleared, nothing to do */
- if (!entries)
- goto unlock;
-
- /* Set thresholds array to NULL if we don't have thresholds */
- if (!size) {
- kfree(new);
- new = NULL;
- goto swap_buffers;
- }
-
- new->size = size;
-
- /* Copy thresholds and find current threshold */
- new->current_threshold = -1;
- for (i = 0, j = 0; i < thresholds->primary->size; i++) {
- if (thresholds->primary->entries[i].eventfd == eventfd)
- continue;
-
- new->entries[j] = thresholds->primary->entries[i];
- if (new->entries[j].threshold <= usage) {
- /*
- * new->current_threshold will not be used
- * until rcu_assign_pointer(), so it's safe to increment
- * it here.
- */
- ++new->current_threshold;
- }
- j++;
- }
-
-swap_buffers:
- /* Swap primary and spare array */
- thresholds->spare = thresholds->primary;
-
- rcu_assign_pointer(thresholds->primary, new);
-
- /* To be sure that nobody uses thresholds */
- synchronize_rcu();
-
- /* If all events are unregistered, free the spare array */
- if (!new) {
- kfree(thresholds->spare);
- thresholds->spare = NULL;
- }
-unlock:
- mutex_unlock(&memcg->thresholds_lock);
-}
-
-static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd)
-{
- return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
-}
-
-static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd)
-{
- return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
-}
-
-static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd, const char *args)
-{
- struct mem_cgroup_eventfd_list *event;
-
- event = kmalloc(sizeof(*event), GFP_KERNEL);
- if (!event)
- return -ENOMEM;
-
- spin_lock(&memcg_oom_lock);
-
- event->eventfd = eventfd;
- list_add(&event->list, &memcg->oom_notify);
-
- /* already in OOM ? */
- if (memcg->under_oom)
- eventfd_signal(eventfd);
- spin_unlock(&memcg_oom_lock);
-
- return 0;
-}
-
-static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
- struct eventfd_ctx *eventfd)
-{
- struct mem_cgroup_eventfd_list *ev, *tmp;
-
- spin_lock(&memcg_oom_lock);
-
- list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
- if (ev->eventfd == eventfd) {
- list_del(&ev->list);
- kfree(ev);
- }
- }
-
- spin_unlock(&memcg_oom_lock);
-}
-
static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
{
struct mem_cgroup *memcg = mem_cgroup_from_seq(sf);
@@ -4613,243 +4184,6 @@ static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
#endif /* CONFIG_CGROUP_WRITEBACK */
-/*
- * DO NOT USE IN NEW FILES.
- *
- * "cgroup.event_control" implementation.
- *
- * This is way over-engineered. It tries to support fully configurable
- * events for each user. Such level of flexibility is completely
- * unnecessary especially in the light of the planned unified hierarchy.
- *
- * Please deprecate this and replace with something simpler if at all
- * possible.
- */
-
-/*
- * Unregister event and free resources.
- *
- * Gets called from workqueue.
- */
-static void memcg_event_remove(struct work_struct *work)
-{
- struct mem_cgroup_event *event =
- container_of(work, struct mem_cgroup_event, remove);
- struct mem_cgroup *memcg = event->memcg;
-
- remove_wait_queue(event->wqh, &event->wait);
-
- event->unregister_event(memcg, event->eventfd);
-
- /* Notify userspace the event is going away. */
- eventfd_signal(event->eventfd);
-
- eventfd_ctx_put(event->eventfd);
- kfree(event);
- css_put(&memcg->css);
-}
-
-/*
- * Gets called on EPOLLHUP on eventfd when user closes it.
- *
- * Called with wqh->lock held and interrupts disabled.
- */
-static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode,
- int sync, void *key)
-{
- struct mem_cgroup_event *event =
- container_of(wait, struct mem_cgroup_event, wait);
- struct mem_cgroup *memcg = event->memcg;
- __poll_t flags = key_to_poll(key);
-
- if (flags & EPOLLHUP) {
- /*
- * If the event has been detached at cgroup removal, we
- * can simply return knowing the other side will cleanup
- * for us.
- *
- * We can't race against event freeing since the other
- * side will require wqh->lock via remove_wait_queue(),
- * which we hold.
- */
- spin_lock(&memcg->event_list_lock);
- if (!list_empty(&event->list)) {
- list_del_init(&event->list);
- /*
- * We are in atomic context, but cgroup_event_remove()
- * may sleep, so we have to call it in workqueue.
- */
- schedule_work(&event->remove);
- }
- spin_unlock(&memcg->event_list_lock);
- }
-
- return 0;
-}
-
-static void memcg_event_ptable_queue_proc(struct file *file,
- wait_queue_head_t *wqh, poll_table *pt)
-{
- struct mem_cgroup_event *event =
- container_of(pt, struct mem_cgroup_event, pt);
-
- event->wqh = wqh;
- add_wait_queue(wqh, &event->wait);
-}
-
-/*
- * DO NOT USE IN NEW FILES.
- *
- * Parse input and register new cgroup event handler.
- *
- * Input must be in format '<event_fd> <control_fd> <args>'.
- * Interpretation of args is defined by control file implementation.
- */
-static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- struct cgroup_subsys_state *css = of_css(of);
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- struct mem_cgroup_event *event;
- struct cgroup_subsys_state *cfile_css;
- unsigned int efd, cfd;
- struct fd efile;
- struct fd cfile;
- struct dentry *cdentry;
- const char *name;
- char *endp;
- int ret;
-
- if (IS_ENABLED(CONFIG_PREEMPT_RT))
- return -EOPNOTSUPP;
-
- buf = strstrip(buf);
-
- efd = simple_strtoul(buf, &endp, 10);
- if (*endp != ' ')
- return -EINVAL;
- buf = endp + 1;
-
- cfd = simple_strtoul(buf, &endp, 10);
- if ((*endp != ' ') && (*endp != '\0'))
- return -EINVAL;
- buf = endp + 1;
-
- event = kzalloc(sizeof(*event), GFP_KERNEL);
- if (!event)
- return -ENOMEM;
-
- event->memcg = memcg;
- INIT_LIST_HEAD(&event->list);
- init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
- init_waitqueue_func_entry(&event->wait, memcg_event_wake);
- INIT_WORK(&event->remove, memcg_event_remove);
-
- efile = fdget(efd);
- if (!efile.file) {
- ret = -EBADF;
- goto out_kfree;
- }
-
- event->eventfd = eventfd_ctx_fileget(efile.file);
- if (IS_ERR(event->eventfd)) {
- ret = PTR_ERR(event->eventfd);
- goto out_put_efile;
- }
-
- cfile = fdget(cfd);
- if (!cfile.file) {
- ret = -EBADF;
- goto out_put_eventfd;
- }
-
- /* the process need read permission on control file */
- /* AV: shouldn't we check that it's been opened for read instead? */
- ret = file_permission(cfile.file, MAY_READ);
- if (ret < 0)
- goto out_put_cfile;
-
- /*
- * The control file must be a regular cgroup1 file. As a regular cgroup
- * file can't be renamed, it's safe to access its name afterwards.
- */
- cdentry = cfile.file->f_path.dentry;
- if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) {
- ret = -EINVAL;
- goto out_put_cfile;
- }
-
- /*
- * Determine the event callbacks and set them in @event. This used
- * to be done via struct cftype but cgroup core no longer knows
- * about these events. The following is crude but the whole thing
- * is for compatibility anyway.
- *
- * DO NOT ADD NEW FILES.
- */
- name = cdentry->d_name.name;
-
- if (!strcmp(name, "memory.usage_in_bytes")) {
- event->register_event = mem_cgroup_usage_register_event;
- event->unregister_event = mem_cgroup_usage_unregister_event;
- } else if (!strcmp(name, "memory.oom_control")) {
- event->register_event = mem_cgroup_oom_register_event;
- event->unregister_event = mem_cgroup_oom_unregister_event;
- } else if (!strcmp(name, "memory.pressure_level")) {
- event->register_event = vmpressure_register_event;
- event->unregister_event = vmpressure_unregister_event;
- } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
- event->register_event = memsw_cgroup_usage_register_event;
- event->unregister_event = memsw_cgroup_usage_unregister_event;
- } else {
- ret = -EINVAL;
- goto out_put_cfile;
- }
-
- /*
- * Verify @cfile should belong to @css. Also, remaining events are
- * automatically removed on cgroup destruction but the removal is
- * asynchronous, so take an extra ref on @css.
- */
- cfile_css = css_tryget_online_from_dir(cdentry->d_parent,
- &memory_cgrp_subsys);
- ret = -EINVAL;
- if (IS_ERR(cfile_css))
- goto out_put_cfile;
- if (cfile_css != css) {
- css_put(cfile_css);
- goto out_put_cfile;
- }
-
- ret = event->register_event(memcg, event->eventfd, buf);
- if (ret)
- goto out_put_css;
-
- vfs_poll(efile.file, &event->pt);
-
- spin_lock_irq(&memcg->event_list_lock);
- list_add(&event->list, &memcg->event_list);
- spin_unlock_irq(&memcg->event_list_lock);
-
- fdput(cfile);
- fdput(efile);
-
- return nbytes;
-
-out_put_css:
- css_put(css);
-out_put_cfile:
- fdput(cfile);
-out_put_eventfd:
- eventfd_ctx_put(event->eventfd);
-out_put_efile:
- fdput(efile);
-out_kfree:
- kfree(event);
-
- return ret;
-}
-
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_SLUB_DEBUG)
static int mem_cgroup_slab_show(struct seq_file *m, void *p)
{
@@ -5316,19 +4650,8 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- struct mem_cgroup_event *event, *tmp;
- /*
- * Unregister events and notify userspace.
- * Notify userspace about cgroup removing only after rmdir of cgroup
- * directory to avoid race between userspace and kernelspace.
- */
- spin_lock_irq(&memcg->event_list_lock);
- list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
- list_del_init(&event->list);
- schedule_work(&event->remove);
- }
- spin_unlock_irq(&memcg->event_list_lock);
+ memcg1_css_offline(memcg);
page_counter_set_min(&memcg->memory, 0);
page_counter_set_low(&memcg->memory, 0);
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c
2024-05-28 20:20 ` [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c Roman Gushchin
@ 2024-06-01 6:33 ` Shakeel Butt
2024-06-04 3:57 ` Roman Gushchin
2024-06-01 6:45 ` Shakeel Butt
1 sibling, 1 reply; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:33 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:58PM GMT, Roman Gushchin wrote:
> Cgroup v1's memory controller contains a pretty complicated
> event notifications mechanism which is not used on cgroup v2.
> Let's move the corresponding code into memcontrol-v1.c.
>
> Please, note, that mem_cgroup_event_ratelimit() remains in
> memcontrol.c, otherwise it would require exporting too many
> details on memcg stats outside of memcontrol.c.
In the followup work, we should decouple v1 only fields from v2 fields
and then we should be able to move mem_cgroup_event_ratelimit() to the
memcontrol-v1.c file.
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c
2024-06-01 6:33 ` Shakeel Butt
@ 2024-06-04 3:57 ` Roman Gushchin
0 siblings, 0 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-06-04 3:57 UTC (permalink / raw)
To: Shakeel Butt
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Fri, May 31, 2024 at 11:33:46PM -0700, Shakeel Butt wrote:
> On Tue, May 28, 2024 at 01:20:58PM GMT, Roman Gushchin wrote:
> > Cgroup v1's memory controller contains a pretty complicated
> > event notifications mechanism which is not used on cgroup v2.
> > Let's move the corresponding code into memcontrol-v1.c.
> >
> > Please, note, that mem_cgroup_event_ratelimit() remains in
> > memcontrol.c, otherwise it would require exporting too many
> > details on memcg stats outside of memcontrol.c.
>
> In the followup work, we should decouple v1 only fields from v2 fields
> and then we should be able to move mem_cgroup_event_ratelimit() to the
> memcontrol-v1.c file.
Right, agree, this is my plan. In the RFC version I had a lot of #ifdef's
in mm/memcontrol.c and now I plan to do it in a nicer way, moving
cgroup v1 - specific stuff into separate functions.
Thanks!
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c
2024-05-28 20:20 ` [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c Roman Gushchin
2024-06-01 6:33 ` Shakeel Butt
@ 2024-06-01 6:45 ` Shakeel Butt
1 sibling, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:45 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:58PM GMT, Roman Gushchin wrote:
> Cgroup v1's memory controller contains a pretty complicated
> event notifications mechanism which is not used on cgroup v2.
> Let's move the corresponding code into memcontrol-v1.c.
>
> Please, note, that mem_cgroup_event_ratelimit() remains in
> memcontrol.c, otherwise it would require exporting too many
> details on memcg stats outside of memcontrol.c.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 07/14] mm: memcg: rename memcg_check_events()
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (5 preceding siblings ...)
2024-05-28 20:20 ` [PATCH v1 06/14] mm: memcg: move legacy memcg event code into memcontrol-v1.c Roman Gushchin
@ 2024-05-28 20:20 ` Roman Gushchin
2024-06-01 6:39 ` Shakeel Butt
2024-06-01 6:46 ` Shakeel Butt
2024-05-28 20:21 ` [PATCH v1 08/14] mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c Roman Gushchin
` (4 subsequent siblings)
11 siblings, 2 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:20 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Rename memcg_check_events() into memcg1_check_events() for
consistency with other cgroup v1-specific functions.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 6 +++---
mm/memcontrol-v1.h | 2 +-
mm/memcontrol.c | 8 ++++----
3 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index c47ffb6105931..8b8c2c9516349 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -835,9 +835,9 @@ static int mem_cgroup_move_account(struct folio *folio,
local_irq_disable();
mem_cgroup_charge_statistics(to, nr_pages);
- memcg_check_events(to, nid);
+ memcg1_check_events(to, nid);
mem_cgroup_charge_statistics(from, -nr_pages);
- memcg_check_events(from, nid);
+ memcg1_check_events(from, nid);
local_irq_enable();
out:
return ret;
@@ -1424,7 +1424,7 @@ static void mem_cgroup_threshold(struct mem_cgroup *memcg)
* Check events in order.
*
*/
-void memcg_check_events(struct mem_cgroup *memcg, int nid)
+void memcg1_check_events(struct mem_cgroup *memcg, int nid)
{
if (IS_ENABLED(CONFIG_PREEMPT_RT))
return;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 524a2c76ffc97..ef1b7037cbdcc 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -12,7 +12,7 @@ static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
}
void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages);
-void memcg_check_events(struct mem_cgroup *memcg, int nid);
+void memcg1_check_events(struct mem_cgroup *memcg, int nid);
void memcg_oom_recover(struct mem_cgroup *memcg);
int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
unsigned int nr_pages);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6bc9009bee517..c14b1b01bcf53 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2632,7 +2632,7 @@ void mem_cgroup_commit_charge(struct folio *folio, struct mem_cgroup *memcg)
local_irq_disable();
mem_cgroup_charge_statistics(memcg, folio_nr_pages(folio));
- memcg_check_events(memcg, folio_nid(folio));
+ memcg1_check_events(memcg, folio_nid(folio));
local_irq_enable();
}
@@ -5699,7 +5699,7 @@ static void uncharge_batch(const struct uncharge_gather *ug)
local_irq_save(flags);
__count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout);
__this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory);
- memcg_check_events(ug->memcg, ug->nid);
+ memcg1_check_events(ug->memcg, ug->nid);
local_irq_restore(flags);
/* drop reference from uncharge_folio */
@@ -5839,7 +5839,7 @@ void mem_cgroup_replace_folio(struct folio *old, struct folio *new)
local_irq_save(flags);
mem_cgroup_charge_statistics(memcg, nr_pages);
- memcg_check_events(memcg, folio_nid(new));
+ memcg1_check_events(memcg, folio_nid(new));
local_irq_restore(flags);
}
@@ -6106,7 +6106,7 @@ void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
memcg_stats_lock();
mem_cgroup_charge_statistics(memcg, -nr_entries);
memcg_stats_unlock();
- memcg_check_events(memcg, folio_nid(folio));
+ memcg1_check_events(memcg, folio_nid(folio));
css_put(&memcg->css);
}
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 07/14] mm: memcg: rename memcg_check_events()
2024-05-28 20:20 ` [PATCH v1 07/14] mm: memcg: rename memcg_check_events() Roman Gushchin
@ 2024-06-01 6:39 ` Shakeel Butt
2024-06-01 6:46 ` Shakeel Butt
1 sibling, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:39 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:59PM GMT, Roman Gushchin wrote:
> Rename memcg_check_events() into memcg1_check_events() for
> consistency with other cgroup v1-specific functions.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
> ---
> mm/memcontrol-v1.c | 6 +++---
> mm/memcontrol-v1.h | 2 +-
> mm/memcontrol.c | 8 ++++----
> 3 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
> index c47ffb6105931..8b8c2c9516349 100644
> --- a/mm/memcontrol-v1.c
> +++ b/mm/memcontrol-v1.c
> @@ -835,9 +835,9 @@ static int mem_cgroup_move_account(struct folio *folio,
>
> local_irq_disable();
> mem_cgroup_charge_statistics(to, nr_pages);
> - memcg_check_events(to, nid);
> + memcg1_check_events(to, nid);
> mem_cgroup_charge_statistics(from, -nr_pages);
> - memcg_check_events(from, nid);
> + memcg1_check_events(from, nid);
> local_irq_enable();
> out:
> return ret;
> @@ -1424,7 +1424,7 @@ static void mem_cgroup_threshold(struct mem_cgroup *memcg)
> * Check events in order.
> *
> */
> -void memcg_check_events(struct mem_cgroup *memcg, int nid)
> +void memcg1_check_events(struct mem_cgroup *memcg, int nid)
> {
> if (IS_ENABLED(CONFIG_PREEMPT_RT))
> return;
> diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
> index 524a2c76ffc97..ef1b7037cbdcc 100644
> --- a/mm/memcontrol-v1.h
> +++ b/mm/memcontrol-v1.h
> @@ -12,7 +12,7 @@ static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
> }
>
> void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages);
> -void memcg_check_events(struct mem_cgroup *memcg, int nid);
> +void memcg1_check_events(struct mem_cgroup *memcg, int nid);
> void memcg_oom_recover(struct mem_cgroup *memcg);
> int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
> unsigned int nr_pages);
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 6bc9009bee517..c14b1b01bcf53 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2632,7 +2632,7 @@ void mem_cgroup_commit_charge(struct folio *folio, struct mem_cgroup *memcg)
>
Once we have memcg->vmstats_v1_percpu field, we can move
mem_cgroup_charge_statistics() to v1 file and the following code blocks
can be abstracted out as well.
> local_irq_disable();
> mem_cgroup_charge_statistics(memcg, folio_nr_pages(folio));
> - memcg_check_events(memcg, folio_nid(folio));
> + memcg1_check_events(memcg, folio_nid(folio));
> local_irq_enable();
> }
>
> @@ -5699,7 +5699,7 @@ static void uncharge_batch(const struct uncharge_gather *ug)
> local_irq_save(flags);
> __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout);
> __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory);
> - memcg_check_events(ug->memcg, ug->nid);
> + memcg1_check_events(ug->memcg, ug->nid);
> local_irq_restore(flags);
>
> /* drop reference from uncharge_folio */
> @@ -5839,7 +5839,7 @@ void mem_cgroup_replace_folio(struct folio *old, struct folio *new)
>
> local_irq_save(flags);
> mem_cgroup_charge_statistics(memcg, nr_pages);
> - memcg_check_events(memcg, folio_nid(new));
> + memcg1_check_events(memcg, folio_nid(new));
> local_irq_restore(flags);
> }
>
> @@ -6106,7 +6106,7 @@ void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
> memcg_stats_lock();
> mem_cgroup_charge_statistics(memcg, -nr_entries);
> memcg_stats_unlock();
> - memcg_check_events(memcg, folio_nid(folio));
> + memcg1_check_events(memcg, folio_nid(folio));
>
> css_put(&memcg->css);
> }
> --
> 2.45.1
>
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 07/14] mm: memcg: rename memcg_check_events()
2024-05-28 20:20 ` [PATCH v1 07/14] mm: memcg: rename memcg_check_events() Roman Gushchin
2024-06-01 6:39 ` Shakeel Butt
@ 2024-06-01 6:46 ` Shakeel Butt
1 sibling, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:46 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:20:59PM GMT, Roman Gushchin wrote:
> Rename memcg_check_events() into memcg1_check_events() for
> consistency with other cgroup v1-specific functions.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 08/14] mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (6 preceding siblings ...)
2024-05-28 20:20 ` [PATCH v1 07/14] mm: memcg: rename memcg_check_events() Roman Gushchin
@ 2024-05-28 20:21 ` Roman Gushchin
2024-06-01 6:46 ` Shakeel Butt
2024-06-01 6:47 ` Shakeel Butt
2024-05-28 20:21 ` [PATCH v1 09/14] mm: memcg: rename memcg_oom_recover() Roman Gushchin
` (3 subsequent siblings)
11 siblings, 2 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:21 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Cgroup v1 supports a complicated OOM handling in userspace mechanism,
which is not supported by cgroup v2. Let's move the corresponding code
into memcontrol-v1.c.
Aside from mechanical code movement this patch introduces two new
functions: memcg1_oom_prepare() and memcg1_oom_finish().
Those are implementing cgroup v1-specific parts of the common memcg
OOM handling path.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 229 ++++++++++++++++++++++++++++++++++++++++++++-
mm/memcontrol-v1.h | 3 +-
mm/memcontrol.c | 216 +-----------------------------------------
3 files changed, 231 insertions(+), 217 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 8b8c2c9516349..6188b33ba03db 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -110,7 +110,13 @@ struct mem_cgroup_event {
struct work_struct remove;
};
-extern spinlock_t memcg_oom_lock;
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map memcg_oom_lock_dep_map = {
+ .name = "memcg_oom_lock",
+};
+#endif
+
+DEFINE_SPINLOCK(memcg_oom_lock);
static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
struct mem_cgroup_tree_per_node *mctz,
@@ -1469,7 +1475,7 @@ static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
return 0;
}
-void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
+static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
{
struct mem_cgroup *iter;
@@ -1959,6 +1965,225 @@ void memcg1_css_offline(struct mem_cgroup *memcg)
spin_unlock_irq(&memcg->event_list_lock);
}
+/*
+ * Check OOM-Killer is already running under our hierarchy.
+ * If someone is running, return false.
+ */
+static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter, *failed = NULL;
+
+ spin_lock(&memcg_oom_lock);
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (iter->oom_lock) {
+ /*
+ * this subtree of our hierarchy is already locked
+ * so we cannot give a lock.
+ */
+ failed = iter;
+ mem_cgroup_iter_break(memcg, iter);
+ break;
+ } else
+ iter->oom_lock = true;
+ }
+
+ if (failed) {
+ /*
+ * OK, we failed to lock the whole subtree so we have
+ * to clean up what we set up to the failing subtree
+ */
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (iter == failed) {
+ mem_cgroup_iter_break(memcg, iter);
+ break;
+ }
+ iter->oom_lock = false;
+ }
+ } else
+ mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
+
+ spin_unlock(&memcg_oom_lock);
+
+ return !failed;
+}
+
+static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ spin_lock(&memcg_oom_lock);
+ mutex_release(&memcg_oom_lock_dep_map, _RET_IP_);
+ for_each_mem_cgroup_tree(iter, memcg)
+ iter->oom_lock = false;
+ spin_unlock(&memcg_oom_lock);
+}
+
+static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ spin_lock(&memcg_oom_lock);
+ for_each_mem_cgroup_tree(iter, memcg)
+ iter->under_oom++;
+ spin_unlock(&memcg_oom_lock);
+}
+
+static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ /*
+ * Be careful about under_oom underflows because a child memcg
+ * could have been added after mem_cgroup_mark_under_oom.
+ */
+ spin_lock(&memcg_oom_lock);
+ for_each_mem_cgroup_tree(iter, memcg)
+ if (iter->under_oom > 0)
+ iter->under_oom--;
+ spin_unlock(&memcg_oom_lock);
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
+
+struct oom_wait_info {
+ struct mem_cgroup *memcg;
+ wait_queue_entry_t wait;
+};
+
+static int memcg_oom_wake_function(wait_queue_entry_t *wait,
+ unsigned mode, int sync, void *arg)
+{
+ struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
+ struct mem_cgroup *oom_wait_memcg;
+ struct oom_wait_info *oom_wait_info;
+
+ oom_wait_info = container_of(wait, struct oom_wait_info, wait);
+ oom_wait_memcg = oom_wait_info->memcg;
+
+ if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) &&
+ !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg))
+ return 0;
+ return autoremove_wake_function(wait, mode, sync, arg);
+}
+
+void memcg_oom_recover(struct mem_cgroup *memcg)
+{
+ /*
+ * For the following lockless ->under_oom test, the only required
+ * guarantee is that it must see the state asserted by an OOM when
+ * this function is called as a result of userland actions
+ * triggered by the notification of the OOM. This is trivially
+ * achieved by invoking mem_cgroup_mark_under_oom() before
+ * triggering notification.
+ */
+ if (memcg && memcg->under_oom)
+ __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
+}
+
+/**
+ * mem_cgroup_oom_synchronize - complete memcg OOM handling
+ * @handle: actually kill/wait or just clean up the OOM state
+ *
+ * This has to be called at the end of a page fault if the memcg OOM
+ * handler was enabled.
+ *
+ * Memcg supports userspace OOM handling where failed allocations must
+ * sleep on a waitqueue until the userspace task resolves the
+ * situation. Sleeping directly in the charge context with all kinds
+ * of locks held is not a good idea, instead we remember an OOM state
+ * in the task and mem_cgroup_oom_synchronize() has to be called at
+ * the end of the page fault to complete the OOM handling.
+ *
+ * Returns %true if an ongoing memcg OOM situation was detected and
+ * completed, %false otherwise.
+ */
+bool mem_cgroup_oom_synchronize(bool handle)
+{
+ struct mem_cgroup *memcg = current->memcg_in_oom;
+ struct oom_wait_info owait;
+ bool locked;
+
+ /* OOM is global, do not handle */
+ if (!memcg)
+ return false;
+
+ if (!handle)
+ goto cleanup;
+
+ owait.memcg = memcg;
+ owait.wait.flags = 0;
+ owait.wait.func = memcg_oom_wake_function;
+ owait.wait.private = current;
+ INIT_LIST_HEAD(&owait.wait.entry);
+
+ prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
+ mem_cgroup_mark_under_oom(memcg);
+
+ locked = mem_cgroup_oom_trylock(memcg);
+
+ if (locked)
+ mem_cgroup_oom_notify(memcg);
+
+ schedule();
+ mem_cgroup_unmark_under_oom(memcg);
+ finish_wait(&memcg_oom_waitq, &owait.wait);
+
+ if (locked)
+ mem_cgroup_oom_unlock(memcg);
+cleanup:
+ current->memcg_in_oom = NULL;
+ css_put(&memcg->css);
+ return true;
+}
+
+
+bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked)
+{
+ /*
+ * We are in the middle of the charge context here, so we
+ * don't want to block when potentially sitting on a callstack
+ * that holds all kinds of filesystem and mm locks.
+ *
+ * cgroup1 allows disabling the OOM killer and waiting for outside
+ * handling until the charge can succeed; remember the context and put
+ * the task to sleep at the end of the page fault when all locks are
+ * released.
+ *
+ * On the other hand, in-kernel OOM killer allows for an async victim
+ * memory reclaim (oom_reaper) and that means that we are not solely
+ * relying on the oom victim to make a forward progress and we can
+ * invoke the oom killer here.
+ *
+ * Please note that mem_cgroup_out_of_memory might fail to find a
+ * victim and then we have to bail out from the charge path.
+ */
+ if (READ_ONCE(memcg->oom_kill_disable)) {
+ if (current->in_user_fault) {
+ css_get(&memcg->css);
+ current->memcg_in_oom = memcg;
+ }
+ return false;
+ }
+
+ mem_cgroup_mark_under_oom(memcg);
+
+ *locked = mem_cgroup_oom_trylock(memcg);
+
+ if (*locked)
+ mem_cgroup_oom_notify(memcg);
+
+ mem_cgroup_unmark_under_oom(memcg);
+
+ return true;
+}
+
+void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked)
+{
+ if (locked)
+ mem_cgroup_oom_unlock(memcg);
+}
+
static int __init memcg1_init(void)
{
int node;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index ef1b7037cbdcc..3de956b2422f1 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -87,9 +87,10 @@ enum res_type {
bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
enum mem_cgroup_events_target target);
unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap);
-void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
ssize_t memcg_write_event_control(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off);
+bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked);
+void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked);
#endif /* __MM_MEMCONTROL_V1_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c14b1b01bcf53..3b088e0078821 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1616,130 +1616,6 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
return ret;
}
-#ifdef CONFIG_LOCKDEP
-static struct lockdep_map memcg_oom_lock_dep_map = {
- .name = "memcg_oom_lock",
-};
-#endif
-
-DEFINE_SPINLOCK(memcg_oom_lock);
-
-/*
- * Check OOM-Killer is already running under our hierarchy.
- * If someone is running, return false.
- */
-static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
-{
- struct mem_cgroup *iter, *failed = NULL;
-
- spin_lock(&memcg_oom_lock);
-
- for_each_mem_cgroup_tree(iter, memcg) {
- if (iter->oom_lock) {
- /*
- * this subtree of our hierarchy is already locked
- * so we cannot give a lock.
- */
- failed = iter;
- mem_cgroup_iter_break(memcg, iter);
- break;
- } else
- iter->oom_lock = true;
- }
-
- if (failed) {
- /*
- * OK, we failed to lock the whole subtree so we have
- * to clean up what we set up to the failing subtree
- */
- for_each_mem_cgroup_tree(iter, memcg) {
- if (iter == failed) {
- mem_cgroup_iter_break(memcg, iter);
- break;
- }
- iter->oom_lock = false;
- }
- } else
- mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
-
- spin_unlock(&memcg_oom_lock);
-
- return !failed;
-}
-
-static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
-{
- struct mem_cgroup *iter;
-
- spin_lock(&memcg_oom_lock);
- mutex_release(&memcg_oom_lock_dep_map, _RET_IP_);
- for_each_mem_cgroup_tree(iter, memcg)
- iter->oom_lock = false;
- spin_unlock(&memcg_oom_lock);
-}
-
-static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
-{
- struct mem_cgroup *iter;
-
- spin_lock(&memcg_oom_lock);
- for_each_mem_cgroup_tree(iter, memcg)
- iter->under_oom++;
- spin_unlock(&memcg_oom_lock);
-}
-
-static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
-{
- struct mem_cgroup *iter;
-
- /*
- * Be careful about under_oom underflows because a child memcg
- * could have been added after mem_cgroup_mark_under_oom.
- */
- spin_lock(&memcg_oom_lock);
- for_each_mem_cgroup_tree(iter, memcg)
- if (iter->under_oom > 0)
- iter->under_oom--;
- spin_unlock(&memcg_oom_lock);
-}
-
-static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
-
-struct oom_wait_info {
- struct mem_cgroup *memcg;
- wait_queue_entry_t wait;
-};
-
-static int memcg_oom_wake_function(wait_queue_entry_t *wait,
- unsigned mode, int sync, void *arg)
-{
- struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
- struct mem_cgroup *oom_wait_memcg;
- struct oom_wait_info *oom_wait_info;
-
- oom_wait_info = container_of(wait, struct oom_wait_info, wait);
- oom_wait_memcg = oom_wait_info->memcg;
-
- if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) &&
- !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg))
- return 0;
- return autoremove_wake_function(wait, mode, sync, arg);
-}
-
-void memcg_oom_recover(struct mem_cgroup *memcg)
-{
- /*
- * For the following lockless ->under_oom test, the only required
- * guarantee is that it must see the state asserted by an OOM when
- * this function is called as a result of userland actions
- * triggered by the notification of the OOM. This is trivially
- * achieved by invoking mem_cgroup_mark_under_oom() before
- * triggering notification.
- */
- if (memcg && memcg->under_oom)
- __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
-}
-
/*
* Returns true if successfully killed one or more processes. Though in some
* corner cases it can return true even without killing any process.
@@ -1753,104 +1629,16 @@ static bool mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
memcg_memory_event(memcg, MEMCG_OOM);
- /*
- * We are in the middle of the charge context here, so we
- * don't want to block when potentially sitting on a callstack
- * that holds all kinds of filesystem and mm locks.
- *
- * cgroup1 allows disabling the OOM killer and waiting for outside
- * handling until the charge can succeed; remember the context and put
- * the task to sleep at the end of the page fault when all locks are
- * released.
- *
- * On the other hand, in-kernel OOM killer allows for an async victim
- * memory reclaim (oom_reaper) and that means that we are not solely
- * relying on the oom victim to make a forward progress and we can
- * invoke the oom killer here.
- *
- * Please note that mem_cgroup_out_of_memory might fail to find a
- * victim and then we have to bail out from the charge path.
- */
- if (READ_ONCE(memcg->oom_kill_disable)) {
- if (current->in_user_fault) {
- css_get(&memcg->css);
- current->memcg_in_oom = memcg;
- }
+ if (!memcg1_oom_prepare(memcg, &locked))
return false;
- }
-
- mem_cgroup_mark_under_oom(memcg);
- locked = mem_cgroup_oom_trylock(memcg);
-
- if (locked)
- mem_cgroup_oom_notify(memcg);
-
- mem_cgroup_unmark_under_oom(memcg);
ret = mem_cgroup_out_of_memory(memcg, mask, order);
- if (locked)
- mem_cgroup_oom_unlock(memcg);
+ memcg1_oom_finish(memcg, locked);
return ret;
}
-/**
- * mem_cgroup_oom_synchronize - complete memcg OOM handling
- * @handle: actually kill/wait or just clean up the OOM state
- *
- * This has to be called at the end of a page fault if the memcg OOM
- * handler was enabled.
- *
- * Memcg supports userspace OOM handling where failed allocations must
- * sleep on a waitqueue until the userspace task resolves the
- * situation. Sleeping directly in the charge context with all kinds
- * of locks held is not a good idea, instead we remember an OOM state
- * in the task and mem_cgroup_oom_synchronize() has to be called at
- * the end of the page fault to complete the OOM handling.
- *
- * Returns %true if an ongoing memcg OOM situation was detected and
- * completed, %false otherwise.
- */
-bool mem_cgroup_oom_synchronize(bool handle)
-{
- struct mem_cgroup *memcg = current->memcg_in_oom;
- struct oom_wait_info owait;
- bool locked;
-
- /* OOM is global, do not handle */
- if (!memcg)
- return false;
-
- if (!handle)
- goto cleanup;
-
- owait.memcg = memcg;
- owait.wait.flags = 0;
- owait.wait.func = memcg_oom_wake_function;
- owait.wait.private = current;
- INIT_LIST_HEAD(&owait.wait.entry);
-
- prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
- mem_cgroup_mark_under_oom(memcg);
-
- locked = mem_cgroup_oom_trylock(memcg);
-
- if (locked)
- mem_cgroup_oom_notify(memcg);
-
- schedule();
- mem_cgroup_unmark_under_oom(memcg);
- finish_wait(&memcg_oom_waitq, &owait.wait);
-
- if (locked)
- mem_cgroup_oom_unlock(memcg);
-cleanup:
- current->memcg_in_oom = NULL;
- css_put(&memcg->css);
- return true;
-}
-
/**
* mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM
* @victim: task to be killed by the OOM killer
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 08/14] mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c
2024-05-28 20:21 ` [PATCH v1 08/14] mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c Roman Gushchin
@ 2024-06-01 6:46 ` Shakeel Butt
2024-06-01 6:47 ` Shakeel Butt
1 sibling, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:46 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:21:00PM GMT, Roman Gushchin wrote:
> Cgroup v1 supports a complicated OOM handling in userspace mechanism,
> which is not supported by cgroup v2. Let's move the corresponding code
> into memcontrol-v1.c.
>
> Aside from mechanical code movement this patch introduces two new
> functions: memcg1_oom_prepare() and memcg1_oom_finish().
> Those are implementing cgroup v1-specific parts of the common memcg
> OOM handling path.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 08/14] mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c
2024-05-28 20:21 ` [PATCH v1 08/14] mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c Roman Gushchin
2024-06-01 6:46 ` Shakeel Butt
@ 2024-06-01 6:47 ` Shakeel Butt
1 sibling, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:47 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:21:00PM GMT, Roman Gushchin wrote:
> Cgroup v1 supports a complicated OOM handling in userspace mechanism,
> which is not supported by cgroup v2. Let's move the corresponding code
> into memcontrol-v1.c.
>
> Aside from mechanical code movement this patch introduces two new
> functions: memcg1_oom_prepare() and memcg1_oom_finish().
> Those are implementing cgroup v1-specific parts of the common memcg
> OOM handling path.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 09/14] mm: memcg: rename memcg_oom_recover()
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (7 preceding siblings ...)
2024-05-28 20:21 ` [PATCH v1 08/14] mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c Roman Gushchin
@ 2024-05-28 20:21 ` Roman Gushchin
2024-06-01 6:48 ` Shakeel Butt
2024-05-28 21:44 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Roman Gushchin
` (2 subsequent siblings)
11 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 20:21 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Rename memcg_oom_recover() into memcg1_oom_recover() for consistency
with other memory cgroup v1-related functions.
Move the declaration in mm/memcontrol-v1.h to be nearby other
memcg v1 oom handling functions.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 6 +++---
mm/memcontrol-v1.h | 2 +-
mm/memcontrol.c | 6 +++---
3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 6188b33ba03db..f73551ff8b2d1 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1090,8 +1090,8 @@ static void __mem_cgroup_clear_mc(void)
mc.moved_swap = 0;
}
- memcg_oom_recover(from);
- memcg_oom_recover(to);
+ memcg1_oom_recover(from);
+ memcg1_oom_recover(to);
wake_up_all(&mc.waitq);
}
@@ -2067,7 +2067,7 @@ static int memcg_oom_wake_function(wait_queue_entry_t *wait,
return autoremove_wake_function(wait, mode, sync, arg);
}
-void memcg_oom_recover(struct mem_cgroup *memcg)
+void memcg1_oom_recover(struct mem_cgroup *memcg)
{
/*
* For the following lockless ->under_oom test, the only required
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 3de956b2422f1..972c493a8ae32 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -13,7 +13,6 @@ static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages);
void memcg1_check_events(struct mem_cgroup *memcg, int nid);
-void memcg_oom_recover(struct mem_cgroup *memcg);
int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
unsigned int nr_pages);
@@ -92,5 +91,6 @@ ssize_t memcg_write_event_control(struct kernfs_open_file *of,
bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked);
void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked);
+void memcg1_oom_recover(struct mem_cgroup *memcg);
#endif /* __MM_MEMCONTROL_V1_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3b088e0078821..1622086cab274 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3169,7 +3169,7 @@ static int mem_cgroup_resize_max(struct mem_cgroup *memcg,
} while (true);
if (!ret && enlarge)
- memcg_oom_recover(memcg);
+ memcg1_oom_recover(memcg);
return ret;
}
@@ -3754,7 +3754,7 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
WRITE_ONCE(memcg->oom_kill_disable, val);
if (!val)
- memcg_oom_recover(memcg);
+ memcg1_oom_recover(memcg);
return 0;
}
@@ -5481,7 +5481,7 @@ static void uncharge_batch(const struct uncharge_gather *ug)
page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory);
if (ug->nr_kmem)
memcg_account_kmem(ug->memcg, -ug->nr_kmem);
- memcg_oom_recover(ug->memcg);
+ memcg1_oom_recover(ug->memcg);
}
local_irq_save(flags);
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 09/14] mm: memcg: rename memcg_oom_recover()
2024-05-28 20:21 ` [PATCH v1 09/14] mm: memcg: rename memcg_oom_recover() Roman Gushchin
@ 2024-06-01 6:48 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:48 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 01:21:01PM GMT, Roman Gushchin wrote:
> Rename memcg_oom_recover() into memcg1_oom_recover() for consistency
> with other memory cgroup v1-related functions.
>
> Move the declaration in mm/memcontrol-v1.h to be nearby other
> memcg v1 oom handling functions.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (8 preceding siblings ...)
2024-05-28 20:21 ` [PATCH v1 09/14] mm: memcg: rename memcg_oom_recover() Roman Gushchin
@ 2024-05-28 21:44 ` Roman Gushchin
2024-05-28 21:44 ` [PATCH v1 11/14] mm: memcg: make memcg1_update_tree() static Roman Gushchin
` (4 more replies)
2024-06-03 19:34 ` [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
2024-06-07 15:29 ` Shakeel Butt
11 siblings, 5 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 21:44 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Move legacy cgroup v1 memory controller interfaces and corresponding
code into memcontrol-v1.c.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 739 ++++++++++++++++++++++++++++++++++++++++++++-
mm/memcontrol-v1.h | 29 +-
mm/memcontrol.c | 721 +------------------------------------------
3 files changed, 767 insertions(+), 722 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index f73551ff8b2d1..3972172f83624 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -10,6 +10,7 @@
#include <linux/poll.h>
#include <linux/sort.h>
#include <linux/file.h>
+#include <linux/seq_buf.h>
#include "internal.h"
#include "swap.h"
@@ -110,6 +111,18 @@ struct mem_cgroup_event {
struct work_struct remove;
};
+#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
+#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
+#define MEMFILE_ATTR(val) ((val) & 0xffff)
+
+enum {
+ RES_USAGE,
+ RES_LIMIT,
+ RES_MAX_USAGE,
+ RES_FAILCNT,
+ RES_SOFT_LIMIT,
+};
+
#ifdef CONFIG_LOCKDEP
static struct lockdep_map memcg_oom_lock_dep_map = {
.name = "memcg_oom_lock",
@@ -577,14 +590,14 @@ static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
}
#endif
-u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
+static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
struct cftype *cft)
{
return mem_cgroup_from_css(css)->move_charge_at_immigrate;
}
#ifdef CONFIG_MMU
-int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
+static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
struct cftype *cft, u64 val)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
@@ -606,7 +619,7 @@ int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
return 0;
}
#else
-int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
+static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
struct cftype *cft, u64 val)
{
return -ENOSYS;
@@ -1803,8 +1816,8 @@ static void memcg_event_ptable_queue_proc(struct file *file,
* Input must be in format '<event_fd> <control_fd> <args>'.
* Interpretation of args is defined by control file implementation.
*/
-ssize_t memcg_write_event_control(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
+static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
struct cgroup_subsys_state *css = of_css(of);
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
@@ -2184,6 +2197,722 @@ void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked)
mem_cgroup_oom_unlock(memcg);
}
+static DEFINE_MUTEX(memcg_max_mutex);
+
+static int mem_cgroup_resize_max(struct mem_cgroup *memcg,
+ unsigned long max, bool memsw)
+{
+ bool enlarge = false;
+ bool drained = false;
+ int ret;
+ bool limits_invariant;
+ struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory;
+
+ do {
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ mutex_lock(&memcg_max_mutex);
+ /*
+ * Make sure that the new limit (memsw or memory limit) doesn't
+ * break our basic invariant rule memory.max <= memsw.max.
+ */
+ limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) :
+ max <= memcg->memsw.max;
+ if (!limits_invariant) {
+ mutex_unlock(&memcg_max_mutex);
+ ret = -EINVAL;
+ break;
+ }
+ if (max > counter->max)
+ enlarge = true;
+ ret = page_counter_set_max(counter, max);
+ mutex_unlock(&memcg_max_mutex);
+
+ if (!ret)
+ break;
+
+ if (!drained) {
+ drain_all_stock(memcg);
+ drained = true;
+ continue;
+ }
+
+ if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL,
+ memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP, NULL)) {
+ ret = -EBUSY;
+ break;
+ }
+ } while (true);
+
+ if (!ret && enlarge)
+ memcg1_oom_recover(memcg);
+
+ return ret;
+}
+
+/*
+ * Reclaims as many pages from the given memcg as possible.
+ *
+ * Caller is responsible for holding css reference for memcg.
+ */
+static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
+{
+ int nr_retries = MAX_RECLAIM_RETRIES;
+
+ /* we call try-to-free pages for make this cgroup empty */
+ lru_add_drain_all();
+
+ drain_all_stock(memcg);
+
+ /* try to free all pages in this cgroup */
+ while (nr_retries && page_counter_read(&memcg->memory)) {
+ if (signal_pending(current))
+ return -EINTR;
+
+ if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL,
+ MEMCG_RECLAIM_MAY_SWAP, NULL))
+ nr_retries--;
+ }
+
+ return 0;
+}
+
+static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+
+ if (mem_cgroup_is_root(memcg))
+ return -EINVAL;
+ return mem_cgroup_force_empty(memcg) ?: nbytes;
+}
+
+static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return 1;
+}
+
+static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ if (val == 1)
+ return 0;
+
+ pr_warn_once("Non-hierarchical mode is deprecated. "
+ "Please report your usecase to linux-mm@kvack.org if you "
+ "depend on this functionality.\n");
+
+ return -EINVAL;
+}
+
+static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct page_counter *counter;
+
+ switch (MEMFILE_TYPE(cft->private)) {
+ case _MEM:
+ counter = &memcg->memory;
+ break;
+ case _MEMSWAP:
+ counter = &memcg->memsw;
+ break;
+ case _KMEM:
+ counter = &memcg->kmem;
+ break;
+ case _TCP:
+ counter = &memcg->tcpmem;
+ break;
+ default:
+ BUG();
+ }
+
+ switch (MEMFILE_ATTR(cft->private)) {
+ case RES_USAGE:
+ if (counter == &memcg->memory)
+ return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE;
+ if (counter == &memcg->memsw)
+ return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE;
+ return (u64)page_counter_read(counter) * PAGE_SIZE;
+ case RES_LIMIT:
+ return (u64)counter->max * PAGE_SIZE;
+ case RES_MAX_USAGE:
+ return (u64)counter->watermark * PAGE_SIZE;
+ case RES_FAILCNT:
+ return counter->failcnt;
+ case RES_SOFT_LIMIT:
+ return (u64)READ_ONCE(memcg->soft_limit) * PAGE_SIZE;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * This function doesn't do anything useful. Its only job is to provide a read
+ * handler for a file so that cgroup_file_mode() will add read permissions.
+ */
+static int mem_cgroup_dummy_seq_show(__always_unused struct seq_file *m,
+ __always_unused void *v)
+{
+ return -EINVAL;
+}
+
+static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max)
+{
+ int ret;
+
+ mutex_lock(&memcg_max_mutex);
+
+ ret = page_counter_set_max(&memcg->tcpmem, max);
+ if (ret)
+ goto out;
+
+ if (!memcg->tcpmem_active) {
+ /*
+ * The active flag needs to be written after the static_key
+ * update. This is what guarantees that the socket activation
+ * function is the last one to run. See mem_cgroup_sk_alloc()
+ * for details, and note that we don't mark any socket as
+ * belonging to this memcg until that flag is up.
+ *
+ * We need to do this, because static_keys will span multiple
+ * sites, but we can't control their order. If we mark a socket
+ * as accounted, but the accounting functions are not patched in
+ * yet, we'll lose accounting.
+ *
+ * We never race with the readers in mem_cgroup_sk_alloc(),
+ * because when this value change, the code to process it is not
+ * patched in yet.
+ */
+ static_branch_inc(&memcg_sockets_enabled_key);
+ memcg->tcpmem_active = true;
+ }
+out:
+ mutex_unlock(&memcg_max_mutex);
+ return ret;
+}
+
+/*
+ * The user of this function is...
+ * RES_LIMIT.
+ */
+static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ unsigned long nr_pages;
+ int ret;
+
+ buf = strstrip(buf);
+ ret = page_counter_memparse(buf, "-1", &nr_pages);
+ if (ret)
+ return ret;
+
+ switch (MEMFILE_ATTR(of_cft(of)->private)) {
+ case RES_LIMIT:
+ if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
+ ret = -EINVAL;
+ break;
+ }
+ switch (MEMFILE_TYPE(of_cft(of)->private)) {
+ case _MEM:
+ ret = mem_cgroup_resize_max(memcg, nr_pages, false);
+ break;
+ case _MEMSWAP:
+ ret = mem_cgroup_resize_max(memcg, nr_pages, true);
+ break;
+ case _KMEM:
+ pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. "
+ "Writing any value to this file has no effect. "
+ "Please report your usecase to linux-mm@kvack.org if you "
+ "depend on this functionality.\n");
+ ret = 0;
+ break;
+ case _TCP:
+ ret = memcg_update_tcp_max(memcg, nr_pages);
+ break;
+ }
+ break;
+ case RES_SOFT_LIMIT:
+ if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ ret = -EOPNOTSUPP;
+ } else {
+ WRITE_ONCE(memcg->soft_limit, nr_pages);
+ ret = 0;
+ }
+ break;
+ }
+ return ret ?: nbytes;
+}
+
+static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ struct page_counter *counter;
+
+ switch (MEMFILE_TYPE(of_cft(of)->private)) {
+ case _MEM:
+ counter = &memcg->memory;
+ break;
+ case _MEMSWAP:
+ counter = &memcg->memsw;
+ break;
+ case _KMEM:
+ counter = &memcg->kmem;
+ break;
+ case _TCP:
+ counter = &memcg->tcpmem;
+ break;
+ default:
+ BUG();
+ }
+
+ switch (MEMFILE_ATTR(of_cft(of)->private)) {
+ case RES_MAX_USAGE:
+ page_counter_reset_watermark(counter);
+ break;
+ case RES_FAILCNT:
+ counter->failcnt = 0;
+ break;
+ default:
+ BUG();
+ }
+
+ return nbytes;
+}
+
+#ifdef CONFIG_NUMA
+
+#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
+#define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
+#define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
+
+/* static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, */
+/* int nid, unsigned int lru_mask, bool tree) */
+/* { */
+/* struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); */
+/* unsigned long nr = 0; */
+/* enum lru_list lru; */
+
+/* VM_BUG_ON((unsigned)nid >= nr_node_ids); */
+
+/* for_each_lru(lru) { */
+/* if (!(BIT(lru) & lru_mask)) */
+/* continue; */
+/* if (tree) */
+/* nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru); */
+/* else */
+/* nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); */
+/* } */
+/* return nr; */
+/* } */
+
+/* static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, */
+/* unsigned int lru_mask, */
+/* bool tree) */
+/* { */
+/* unsigned long nr = 0; */
+/* enum lru_list lru; */
+
+/* for_each_lru(lru) { */
+/* if (!(BIT(lru) & lru_mask)) */
+/* continue; */
+/* if (tree) */
+/* nr += memcg_page_state(memcg, NR_LRU_BASE + lru); */
+/* else */
+/* nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); */
+/* } */
+/* return nr; */
+/* } */
+
+static int memcg_numa_stat_show(struct seq_file *m, void *v)
+{
+ struct numa_stat {
+ const char *name;
+ unsigned int lru_mask;
+ };
+
+ static const struct numa_stat stats[] = {
+ { "total", LRU_ALL },
+ { "file", LRU_ALL_FILE },
+ { "anon", LRU_ALL_ANON },
+ { "unevictable", BIT(LRU_UNEVICTABLE) },
+ };
+ const struct numa_stat *stat;
+ int nid;
+ struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
+
+ mem_cgroup_flush_stats(memcg);
+
+ for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
+ seq_printf(m, "%s=%lu", stat->name,
+ mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
+ false));
+ for_each_node_state(nid, N_MEMORY)
+ seq_printf(m, " N%d=%lu", nid,
+ mem_cgroup_node_nr_lru_pages(memcg, nid,
+ stat->lru_mask, false));
+ seq_putc(m, '\n');
+ }
+
+ for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
+
+ seq_printf(m, "hierarchical_%s=%lu", stat->name,
+ mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
+ true));
+ for_each_node_state(nid, N_MEMORY)
+ seq_printf(m, " N%d=%lu", nid,
+ mem_cgroup_node_nr_lru_pages(memcg, nid,
+ stat->lru_mask, true));
+ seq_putc(m, '\n');
+ }
+
+ return 0;
+}
+#endif /* CONFIG_NUMA */
+
+static const unsigned int memcg1_stats[] = {
+ NR_FILE_PAGES,
+ NR_ANON_MAPPED,
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ NR_ANON_THPS,
+#endif
+ NR_SHMEM,
+ NR_FILE_MAPPED,
+ NR_FILE_DIRTY,
+ NR_WRITEBACK,
+ WORKINGSET_REFAULT_ANON,
+ WORKINGSET_REFAULT_FILE,
+#ifdef CONFIG_SWAP
+ MEMCG_SWAP,
+ NR_SWAPCACHE,
+#endif
+};
+
+static const char *const memcg1_stat_names[] = {
+ "cache",
+ "rss",
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ "rss_huge",
+#endif
+ "shmem",
+ "mapped_file",
+ "dirty",
+ "writeback",
+ "workingset_refault_anon",
+ "workingset_refault_file",
+#ifdef CONFIG_SWAP
+ "swap",
+ "swapcached",
+#endif
+};
+
+/* Universal VM events cgroup1 shows, original sort order */
+static const unsigned int memcg1_events[] = {
+ PGPGIN,
+ PGPGOUT,
+ PGFAULT,
+ PGMAJFAULT,
+};
+
+void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
+{
+ unsigned long memory, memsw;
+ struct mem_cgroup *mi;
+ unsigned int i;
+
+ BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats));
+
+ mem_cgroup_flush_stats(memcg);
+
+ for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
+ unsigned long nr;
+
+ nr = memcg_page_state_local_output(memcg, memcg1_stats[i]);
+ seq_buf_printf(s, "%s %lu\n", memcg1_stat_names[i], nr);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
+ seq_buf_printf(s, "%s %lu\n", vm_event_name(memcg1_events[i]),
+ memcg_events_local(memcg, memcg1_events[i]));
+
+ for (i = 0; i < NR_LRU_LISTS; i++)
+ seq_buf_printf(s, "%s %lu\n", lru_list_name(i),
+ memcg_page_state_local(memcg, NR_LRU_BASE + i) *
+ PAGE_SIZE);
+
+ /* Hierarchical information */
+ memory = memsw = PAGE_COUNTER_MAX;
+ for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
+ memory = min(memory, READ_ONCE(mi->memory.max));
+ memsw = min(memsw, READ_ONCE(mi->memsw.max));
+ }
+ seq_buf_printf(s, "hierarchical_memory_limit %llu\n",
+ (u64)memory * PAGE_SIZE);
+ seq_buf_printf(s, "hierarchical_memsw_limit %llu\n",
+ (u64)memsw * PAGE_SIZE);
+
+ for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
+ unsigned long nr;
+
+ nr = memcg_page_state_output(memcg, memcg1_stats[i]);
+ seq_buf_printf(s, "total_%s %llu\n", memcg1_stat_names[i],
+ (u64)nr);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
+ seq_buf_printf(s, "total_%s %llu\n",
+ vm_event_name(memcg1_events[i]),
+ (u64)memcg_events(memcg, memcg1_events[i]));
+
+ for (i = 0; i < NR_LRU_LISTS; i++)
+ seq_buf_printf(s, "total_%s %llu\n", lru_list_name(i),
+ (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
+ PAGE_SIZE);
+
+#ifdef CONFIG_DEBUG_VM
+ {
+ pg_data_t *pgdat;
+ struct mem_cgroup_per_node *mz;
+ unsigned long anon_cost = 0;
+ unsigned long file_cost = 0;
+
+ for_each_online_pgdat(pgdat) {
+ mz = memcg->nodeinfo[pgdat->node_id];
+
+ anon_cost += mz->lruvec.anon_cost;
+ file_cost += mz->lruvec.file_cost;
+ }
+ seq_buf_printf(s, "anon_cost %lu\n", anon_cost);
+ seq_buf_printf(s, "file_cost %lu\n", file_cost);
+ }
+#endif
+}
+
+static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ return mem_cgroup_swappiness(memcg);
+}
+
+static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ if (val > MAX_SWAPPINESS)
+ return -EINVAL;
+
+ if (!mem_cgroup_is_root(memcg))
+ WRITE_ONCE(memcg->swappiness, val);
+ else
+ WRITE_ONCE(vm_swappiness, val);
+
+ return 0;
+}
+
+static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_seq(sf);
+
+ seq_printf(sf, "oom_kill_disable %d\n", READ_ONCE(memcg->oom_kill_disable));
+ seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom);
+ seq_printf(sf, "oom_kill %lu\n",
+ atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL]));
+ return 0;
+}
+
+static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ /* cannot set to root cgroup and only 0 and 1 are allowed */
+ if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1)))
+ return -EINVAL;
+
+ WRITE_ONCE(memcg->oom_kill_disable, val);
+ if (!val)
+ memcg1_oom_recover(memcg);
+
+ return 0;
+}
+
+#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_SLUB_DEBUG)
+static int mem_cgroup_slab_show(struct seq_file *m, void *p)
+{
+ /*
+ * Deprecated.
+ * Please, take a look at tools/cgroup/memcg_slabinfo.py .
+ */
+ return 0;
+}
+#endif
+
+struct cftype mem_cgroup_legacy_files[] = {
+ {
+ .name = "usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "soft_limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "failcnt",
+ .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "stat",
+ .seq_show = memory_stat_show,
+ },
+ {
+ .name = "force_empty",
+ .write = mem_cgroup_force_empty_write,
+ },
+ {
+ .name = "use_hierarchy",
+ .write_u64 = mem_cgroup_hierarchy_write,
+ .read_u64 = mem_cgroup_hierarchy_read,
+ },
+ {
+ .name = "cgroup.event_control", /* XXX: for compat */
+ .write = memcg_write_event_control,
+ .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE,
+ },
+ {
+ .name = "swappiness",
+ .read_u64 = mem_cgroup_swappiness_read,
+ .write_u64 = mem_cgroup_swappiness_write,
+ },
+ {
+ .name = "move_charge_at_immigrate",
+ .read_u64 = mem_cgroup_move_charge_read,
+ .write_u64 = mem_cgroup_move_charge_write,
+ },
+ {
+ .name = "oom_control",
+ .seq_show = mem_cgroup_oom_control_read,
+ .write_u64 = mem_cgroup_oom_control_write,
+ },
+ {
+ .name = "pressure_level",
+ .seq_show = mem_cgroup_dummy_seq_show,
+ },
+#ifdef CONFIG_NUMA
+ {
+ .name = "numa_stat",
+ .seq_show = memcg_numa_stat_show,
+ },
+#endif
+ {
+ .name = "kmem.limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.failcnt",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_SLUB_DEBUG)
+ {
+ .name = "kmem.slabinfo",
+ .seq_show = mem_cgroup_slab_show,
+ },
+#endif
+ {
+ .name = "kmem.tcp.limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.tcp.usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_TCP, RES_USAGE),
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.tcp.failcnt",
+ .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "kmem.tcp.max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ { }, /* terminate */
+};
+
+struct cftype memsw_files[] = {
+ {
+ .name = "memsw.usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "memsw.max_usage_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "memsw.limit_in_bytes",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
+ .write = mem_cgroup_write,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ {
+ .name = "memsw.failcnt",
+ .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
+ .write = mem_cgroup_reset,
+ .read_u64 = mem_cgroup_read_u64,
+ },
+ { }, /* terminate */
+};
+
static int __init memcg1_init(void)
{
int node;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 972c493a8ae32..7be4670d9abbb 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -3,6 +3,8 @@
#ifndef __MM_MEMCONTROL_V1_H
#define __MM_MEMCONTROL_V1_H
+#include <linux/cgroup-defs.h>
+
void memcg1_update_tree(struct mem_cgroup *memcg, int nid);
void memcg1_remove_from_trees(struct mem_cgroup *memcg);
@@ -34,12 +36,6 @@ int memcg1_can_attach(struct cgroup_taskset *tset);
void memcg1_cancel_attach(struct cgroup_taskset *tset);
void memcg1_move_task(void);
-struct cftype;
-u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
- struct cftype *cft);
-int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val);
-
/*
* Per memcg event counter is incremented at every pagein/pageout. With THP,
* it will be incremented by the number of pages. This counter is used
@@ -86,11 +82,28 @@ enum res_type {
bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
enum mem_cgroup_events_target target);
unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap);
-ssize_t memcg_write_event_control(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off);
bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked);
void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked);
void memcg1_oom_recover(struct mem_cgroup *memcg);
+void drain_all_stock(struct mem_cgroup *root_memcg);
+unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
+ unsigned int lru_mask, bool tree);
+unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+ int nid, unsigned int lru_mask,
+ bool tree);
+
+unsigned long memcg_events(struct mem_cgroup *memcg, int event);
+unsigned long memcg_events_local(struct mem_cgroup *memcg, int event);
+unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx);
+unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item);
+unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item);
+int memory_stat_show(struct seq_file *m, void *v);
+
+void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
+
+extern struct cftype memsw_files[];
+extern struct cftype mem_cgroup_legacy_files[];
+
#endif /* __MM_MEMCONTROL_V1_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1622086cab274..8a28ba4ca93ea 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -96,10 +96,6 @@ static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq);
#define THRESHOLDS_EVENTS_TARGET 128
#define SOFTLIMIT_EVENTS_TARGET 1024
-#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
-#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
-#define MEMFILE_ATTR(val) ((val) & 0xffff)
-
static inline bool task_is_dying(void)
{
return tsk_is_oom_victim(current) || fatal_signal_pending(current) ||
@@ -676,7 +672,7 @@ void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
}
/* idx can be of type enum memcg_stat_item or node_stat_item. */
-static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
+unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
{
long x;
int i = memcg_stats_index(idx);
@@ -825,7 +821,7 @@ void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
memcg_stats_unlock();
}
-static unsigned long memcg_events(struct mem_cgroup *memcg, int event)
+unsigned long memcg_events(struct mem_cgroup *memcg, int event)
{
int i = memcg_events_index(event);
@@ -835,7 +831,7 @@ static unsigned long memcg_events(struct mem_cgroup *memcg, int event)
return READ_ONCE(memcg->vmstats->events[i]);
}
-static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
+unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
{
int i = memcg_events_index(event);
@@ -1420,15 +1416,13 @@ static int memcg_page_state_output_unit(int item)
}
}
-static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg,
- int item)
+unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item)
{
return memcg_page_state(memcg, item) *
memcg_page_state_output_unit(item);
}
-static inline unsigned long memcg_page_state_local_output(
- struct mem_cgroup *memcg, int item)
+unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item)
{
return memcg_page_state_local(memcg, item) *
memcg_page_state_output_unit(item);
@@ -1487,8 +1481,6 @@ static void memcg_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
WARN_ON_ONCE(seq_buf_has_overflowed(s));
}
-static void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
-
static void memory_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
{
if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
@@ -1861,7 +1853,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
* Drains all per-CPU charge caches for given root_memcg resp. subtree
* of the hierarchy under it.
*/
-static void drain_all_stock(struct mem_cgroup *root_memcg)
+void drain_all_stock(struct mem_cgroup *root_memcg)
{
int cpu, curcpu;
@@ -3117,120 +3109,6 @@ void split_page_memcg(struct page *head, int old_order, int new_order)
css_get_many(&memcg->css, old_nr / new_nr - 1);
}
-
-static DEFINE_MUTEX(memcg_max_mutex);
-
-static int mem_cgroup_resize_max(struct mem_cgroup *memcg,
- unsigned long max, bool memsw)
-{
- bool enlarge = false;
- bool drained = false;
- int ret;
- bool limits_invariant;
- struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory;
-
- do {
- if (signal_pending(current)) {
- ret = -EINTR;
- break;
- }
-
- mutex_lock(&memcg_max_mutex);
- /*
- * Make sure that the new limit (memsw or memory limit) doesn't
- * break our basic invariant rule memory.max <= memsw.max.
- */
- limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) :
- max <= memcg->memsw.max;
- if (!limits_invariant) {
- mutex_unlock(&memcg_max_mutex);
- ret = -EINVAL;
- break;
- }
- if (max > counter->max)
- enlarge = true;
- ret = page_counter_set_max(counter, max);
- mutex_unlock(&memcg_max_mutex);
-
- if (!ret)
- break;
-
- if (!drained) {
- drain_all_stock(memcg);
- drained = true;
- continue;
- }
-
- if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL,
- memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP, NULL)) {
- ret = -EBUSY;
- break;
- }
- } while (true);
-
- if (!ret && enlarge)
- memcg1_oom_recover(memcg);
-
- return ret;
-}
-
-/*
- * Reclaims as many pages from the given memcg as possible.
- *
- * Caller is responsible for holding css reference for memcg.
- */
-static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
-{
- int nr_retries = MAX_RECLAIM_RETRIES;
-
- /* we call try-to-free pages for make this cgroup empty */
- lru_add_drain_all();
-
- drain_all_stock(memcg);
-
- /* try to free all pages in this cgroup */
- while (nr_retries && page_counter_read(&memcg->memory)) {
- if (signal_pending(current))
- return -EINTR;
-
- if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL,
- MEMCG_RECLAIM_MAY_SWAP, NULL))
- nr_retries--;
- }
-
- return 0;
-}
-
-static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes,
- loff_t off)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
-
- if (mem_cgroup_is_root(memcg))
- return -EINVAL;
- return mem_cgroup_force_empty(memcg) ?: nbytes;
-}
-
-static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return 1;
-}
-
-static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val)
-{
- if (val == 1)
- return 0;
-
- pr_warn_once("Non-hierarchical mode is deprecated. "
- "Please report your usecase to linux-mm@kvack.org if you "
- "depend on this functionality.\n");
-
- return -EINVAL;
-}
-
unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
{
unsigned long val;
@@ -3253,67 +3131,6 @@ unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
return val;
}
-enum {
- RES_USAGE,
- RES_LIMIT,
- RES_MAX_USAGE,
- RES_FAILCNT,
- RES_SOFT_LIMIT,
-};
-
-static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- struct page_counter *counter;
-
- switch (MEMFILE_TYPE(cft->private)) {
- case _MEM:
- counter = &memcg->memory;
- break;
- case _MEMSWAP:
- counter = &memcg->memsw;
- break;
- case _KMEM:
- counter = &memcg->kmem;
- break;
- case _TCP:
- counter = &memcg->tcpmem;
- break;
- default:
- BUG();
- }
-
- switch (MEMFILE_ATTR(cft->private)) {
- case RES_USAGE:
- if (counter == &memcg->memory)
- return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE;
- if (counter == &memcg->memsw)
- return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE;
- return (u64)page_counter_read(counter) * PAGE_SIZE;
- case RES_LIMIT:
- return (u64)counter->max * PAGE_SIZE;
- case RES_MAX_USAGE:
- return (u64)counter->watermark * PAGE_SIZE;
- case RES_FAILCNT:
- return counter->failcnt;
- case RES_SOFT_LIMIT:
- return (u64)READ_ONCE(memcg->soft_limit) * PAGE_SIZE;
- default:
- BUG();
- }
-}
-
-/*
- * This function doesn't do anything useful. Its only job is to provide a read
- * handler for a file so that cgroup_file_mode() will add read permissions.
- */
-static int mem_cgroup_dummy_seq_show(__always_unused struct seq_file *m,
- __always_unused void *v)
-{
- return -EINVAL;
-}
-
#ifdef CONFIG_MEMCG_KMEM
static int memcg_online_kmem(struct mem_cgroup *memcg)
{
@@ -3375,139 +3192,9 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
}
#endif /* CONFIG_MEMCG_KMEM */
-static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max)
-{
- int ret;
-
- mutex_lock(&memcg_max_mutex);
-
- ret = page_counter_set_max(&memcg->tcpmem, max);
- if (ret)
- goto out;
-
- if (!memcg->tcpmem_active) {
- /*
- * The active flag needs to be written after the static_key
- * update. This is what guarantees that the socket activation
- * function is the last one to run. See mem_cgroup_sk_alloc()
- * for details, and note that we don't mark any socket as
- * belonging to this memcg until that flag is up.
- *
- * We need to do this, because static_keys will span multiple
- * sites, but we can't control their order. If we mark a socket
- * as accounted, but the accounting functions are not patched in
- * yet, we'll lose accounting.
- *
- * We never race with the readers in mem_cgroup_sk_alloc(),
- * because when this value change, the code to process it is not
- * patched in yet.
- */
- static_branch_inc(&memcg_sockets_enabled_key);
- memcg->tcpmem_active = true;
- }
-out:
- mutex_unlock(&memcg_max_mutex);
- return ret;
-}
-
-/*
- * The user of this function is...
- * RES_LIMIT.
- */
-static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
- unsigned long nr_pages;
- int ret;
-
- buf = strstrip(buf);
- ret = page_counter_memparse(buf, "-1", &nr_pages);
- if (ret)
- return ret;
-
- switch (MEMFILE_ATTR(of_cft(of)->private)) {
- case RES_LIMIT:
- if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
- ret = -EINVAL;
- break;
- }
- switch (MEMFILE_TYPE(of_cft(of)->private)) {
- case _MEM:
- ret = mem_cgroup_resize_max(memcg, nr_pages, false);
- break;
- case _MEMSWAP:
- ret = mem_cgroup_resize_max(memcg, nr_pages, true);
- break;
- case _KMEM:
- pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. "
- "Writing any value to this file has no effect. "
- "Please report your usecase to linux-mm@kvack.org if you "
- "depend on this functionality.\n");
- ret = 0;
- break;
- case _TCP:
- ret = memcg_update_tcp_max(memcg, nr_pages);
- break;
- }
- break;
- case RES_SOFT_LIMIT:
- if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
- ret = -EOPNOTSUPP;
- } else {
- WRITE_ONCE(memcg->soft_limit, nr_pages);
- ret = 0;
- }
- break;
- }
- return ret ?: nbytes;
-}
-
-static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
- size_t nbytes, loff_t off)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
- struct page_counter *counter;
-
- switch (MEMFILE_TYPE(of_cft(of)->private)) {
- case _MEM:
- counter = &memcg->memory;
- break;
- case _MEMSWAP:
- counter = &memcg->memsw;
- break;
- case _KMEM:
- counter = &memcg->kmem;
- break;
- case _TCP:
- counter = &memcg->tcpmem;
- break;
- default:
- BUG();
- }
-
- switch (MEMFILE_ATTR(of_cft(of)->private)) {
- case RES_MAX_USAGE:
- page_counter_reset_watermark(counter);
- break;
- case RES_FAILCNT:
- counter->failcnt = 0;
- break;
- default:
- BUG();
- }
-
- return nbytes;
-}
-
-#ifdef CONFIG_NUMA
-
-#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
-#define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
-#define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
-
-static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
- int nid, unsigned int lru_mask, bool tree)
+unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+ int nid, unsigned int lru_mask,
+ bool tree)
{
struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid));
unsigned long nr = 0;
@@ -3526,9 +3213,8 @@ static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
return nr;
}
-static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
- unsigned int lru_mask,
- bool tree)
+unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
+ unsigned int lru_mask, bool tree)
{
unsigned long nr = 0;
enum lru_list lru;
@@ -3544,221 +3230,6 @@ static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
return nr;
}
-static int memcg_numa_stat_show(struct seq_file *m, void *v)
-{
- struct numa_stat {
- const char *name;
- unsigned int lru_mask;
- };
-
- static const struct numa_stat stats[] = {
- { "total", LRU_ALL },
- { "file", LRU_ALL_FILE },
- { "anon", LRU_ALL_ANON },
- { "unevictable", BIT(LRU_UNEVICTABLE) },
- };
- const struct numa_stat *stat;
- int nid;
- struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
-
- mem_cgroup_flush_stats(memcg);
-
- for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
- seq_printf(m, "%s=%lu", stat->name,
- mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
- false));
- for_each_node_state(nid, N_MEMORY)
- seq_printf(m, " N%d=%lu", nid,
- mem_cgroup_node_nr_lru_pages(memcg, nid,
- stat->lru_mask, false));
- seq_putc(m, '\n');
- }
-
- for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
-
- seq_printf(m, "hierarchical_%s=%lu", stat->name,
- mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
- true));
- for_each_node_state(nid, N_MEMORY)
- seq_printf(m, " N%d=%lu", nid,
- mem_cgroup_node_nr_lru_pages(memcg, nid,
- stat->lru_mask, true));
- seq_putc(m, '\n');
- }
-
- return 0;
-}
-#endif /* CONFIG_NUMA */
-
-static const unsigned int memcg1_stats[] = {
- NR_FILE_PAGES,
- NR_ANON_MAPPED,
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- NR_ANON_THPS,
-#endif
- NR_SHMEM,
- NR_FILE_MAPPED,
- NR_FILE_DIRTY,
- NR_WRITEBACK,
- WORKINGSET_REFAULT_ANON,
- WORKINGSET_REFAULT_FILE,
-#ifdef CONFIG_SWAP
- MEMCG_SWAP,
- NR_SWAPCACHE,
-#endif
-};
-
-static const char *const memcg1_stat_names[] = {
- "cache",
- "rss",
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- "rss_huge",
-#endif
- "shmem",
- "mapped_file",
- "dirty",
- "writeback",
- "workingset_refault_anon",
- "workingset_refault_file",
-#ifdef CONFIG_SWAP
- "swap",
- "swapcached",
-#endif
-};
-
-/* Universal VM events cgroup1 shows, original sort order */
-static const unsigned int memcg1_events[] = {
- PGPGIN,
- PGPGOUT,
- PGFAULT,
- PGMAJFAULT,
-};
-
-static void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
-{
- unsigned long memory, memsw;
- struct mem_cgroup *mi;
- unsigned int i;
-
- BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats));
-
- mem_cgroup_flush_stats(memcg);
-
- for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
- unsigned long nr;
-
- nr = memcg_page_state_local_output(memcg, memcg1_stats[i]);
- seq_buf_printf(s, "%s %lu\n", memcg1_stat_names[i], nr);
- }
-
- for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
- seq_buf_printf(s, "%s %lu\n", vm_event_name(memcg1_events[i]),
- memcg_events_local(memcg, memcg1_events[i]));
-
- for (i = 0; i < NR_LRU_LISTS; i++)
- seq_buf_printf(s, "%s %lu\n", lru_list_name(i),
- memcg_page_state_local(memcg, NR_LRU_BASE + i) *
- PAGE_SIZE);
-
- /* Hierarchical information */
- memory = memsw = PAGE_COUNTER_MAX;
- for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
- memory = min(memory, READ_ONCE(mi->memory.max));
- memsw = min(memsw, READ_ONCE(mi->memsw.max));
- }
- seq_buf_printf(s, "hierarchical_memory_limit %llu\n",
- (u64)memory * PAGE_SIZE);
- seq_buf_printf(s, "hierarchical_memsw_limit %llu\n",
- (u64)memsw * PAGE_SIZE);
-
- for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
- unsigned long nr;
-
- nr = memcg_page_state_output(memcg, memcg1_stats[i]);
- seq_buf_printf(s, "total_%s %llu\n", memcg1_stat_names[i],
- (u64)nr);
- }
-
- for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
- seq_buf_printf(s, "total_%s %llu\n",
- vm_event_name(memcg1_events[i]),
- (u64)memcg_events(memcg, memcg1_events[i]));
-
- for (i = 0; i < NR_LRU_LISTS; i++)
- seq_buf_printf(s, "total_%s %llu\n", lru_list_name(i),
- (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
- PAGE_SIZE);
-
-#ifdef CONFIG_DEBUG_VM
- {
- pg_data_t *pgdat;
- struct mem_cgroup_per_node *mz;
- unsigned long anon_cost = 0;
- unsigned long file_cost = 0;
-
- for_each_online_pgdat(pgdat) {
- mz = memcg->nodeinfo[pgdat->node_id];
-
- anon_cost += mz->lruvec.anon_cost;
- file_cost += mz->lruvec.file_cost;
- }
- seq_buf_printf(s, "anon_cost %lu\n", anon_cost);
- seq_buf_printf(s, "file_cost %lu\n", file_cost);
- }
-#endif
-}
-
-static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
-
- return mem_cgroup_swappiness(memcg);
-}
-
-static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
-
- if (val > MAX_SWAPPINESS)
- return -EINVAL;
-
- if (!mem_cgroup_is_root(memcg))
- WRITE_ONCE(memcg->swappiness, val);
- else
- WRITE_ONCE(vm_swappiness, val);
-
- return 0;
-}
-
-static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_seq(sf);
-
- seq_printf(sf, "oom_kill_disable %d\n", READ_ONCE(memcg->oom_kill_disable));
- seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom);
- seq_printf(sf, "oom_kill %lu\n",
- atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL]));
- return 0;
-}
-
-static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
-
- /* cannot set to root cgroup and only 0 and 1 are allowed */
- if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1)))
- return -EINVAL;
-
- WRITE_ONCE(memcg->oom_kill_disable, val);
- if (!val)
- memcg1_oom_recover(memcg);
-
- return 0;
-}
-
#ifdef CONFIG_CGROUP_WRITEBACK
#include <trace/events/writeback.h>
@@ -3972,147 +3443,6 @@ static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
#endif /* CONFIG_CGROUP_WRITEBACK */
-#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_SLUB_DEBUG)
-static int mem_cgroup_slab_show(struct seq_file *m, void *p)
-{
- /*
- * Deprecated.
- * Please, take a look at tools/cgroup/memcg_slabinfo.py .
- */
- return 0;
-}
-#endif
-
-static int memory_stat_show(struct seq_file *m, void *v);
-
-static struct cftype mem_cgroup_legacy_files[] = {
- {
- .name = "usage_in_bytes",
- .private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "max_usage_in_bytes",
- .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "limit_in_bytes",
- .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
- .write = mem_cgroup_write,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "soft_limit_in_bytes",
- .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
- .write = mem_cgroup_write,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "failcnt",
- .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "stat",
- .seq_show = memory_stat_show,
- },
- {
- .name = "force_empty",
- .write = mem_cgroup_force_empty_write,
- },
- {
- .name = "use_hierarchy",
- .write_u64 = mem_cgroup_hierarchy_write,
- .read_u64 = mem_cgroup_hierarchy_read,
- },
- {
- .name = "cgroup.event_control", /* XXX: for compat */
- .write = memcg_write_event_control,
- .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE,
- },
- {
- .name = "swappiness",
- .read_u64 = mem_cgroup_swappiness_read,
- .write_u64 = mem_cgroup_swappiness_write,
- },
- {
- .name = "move_charge_at_immigrate",
- .read_u64 = mem_cgroup_move_charge_read,
- .write_u64 = mem_cgroup_move_charge_write,
- },
- {
- .name = "oom_control",
- .seq_show = mem_cgroup_oom_control_read,
- .write_u64 = mem_cgroup_oom_control_write,
- },
- {
- .name = "pressure_level",
- .seq_show = mem_cgroup_dummy_seq_show,
- },
-#ifdef CONFIG_NUMA
- {
- .name = "numa_stat",
- .seq_show = memcg_numa_stat_show,
- },
-#endif
- {
- .name = "kmem.limit_in_bytes",
- .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
- .write = mem_cgroup_write,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "kmem.usage_in_bytes",
- .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "kmem.failcnt",
- .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "kmem.max_usage_in_bytes",
- .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
-#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_SLUB_DEBUG)
- {
- .name = "kmem.slabinfo",
- .seq_show = mem_cgroup_slab_show,
- },
-#endif
- {
- .name = "kmem.tcp.limit_in_bytes",
- .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT),
- .write = mem_cgroup_write,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "kmem.tcp.usage_in_bytes",
- .private = MEMFILE_PRIVATE(_TCP, RES_USAGE),
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "kmem.tcp.failcnt",
- .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "kmem.tcp.max_usage_in_bytes",
- .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
- { }, /* terminate */
-};
-
/*
* Private memory cgroup IDR
*
@@ -4904,7 +4234,7 @@ static int memory_events_local_show(struct seq_file *m, void *v)
return 0;
}
-static int memory_stat_show(struct seq_file *m, void *v)
+int memory_stat_show(struct seq_file *m, void *v)
{
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
@@ -6135,33 +5465,6 @@ static struct cftype swap_files[] = {
{ } /* terminate */
};
-static struct cftype memsw_files[] = {
- {
- .name = "memsw.usage_in_bytes",
- .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "memsw.max_usage_in_bytes",
- .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "memsw.limit_in_bytes",
- .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
- .write = mem_cgroup_write,
- .read_u64 = mem_cgroup_read_u64,
- },
- {
- .name = "memsw.failcnt",
- .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
- .write = mem_cgroup_reset,
- .read_u64 = mem_cgroup_read_u64,
- },
- { }, /* terminate */
-};
-
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
/**
* obj_cgroup_may_zswap - check if this cgroup can zswap
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* [PATCH v1 11/14] mm: memcg: make memcg1_update_tree() static
2024-05-28 21:44 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Roman Gushchin
@ 2024-05-28 21:44 ` Roman Gushchin
2024-06-01 6:48 ` Shakeel Butt
2024-05-28 21:44 ` [PATCH v1 12/14] mm: memcg: group cgroup v1 memcg related declarations Roman Gushchin
` (3 subsequent siblings)
4 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 21:44 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
memcg1_update_tree() is not used outside of mm/memcontrol-v1.c
anymore, define it as static and remove the declaration from
the header file.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol-v1.c | 2 +-
mm/memcontrol-v1.h | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 3972172f83624..b69181322fb18 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -201,7 +201,7 @@ static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
return excess;
}
-void memcg1_update_tree(struct mem_cgroup *memcg, int nid)
+static void memcg1_update_tree(struct mem_cgroup *memcg, int nid)
{
unsigned long excess;
struct mem_cgroup_per_node *mz;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 7be4670d9abbb..7d6ac4a4fb36d 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -5,7 +5,6 @@
#include <linux/cgroup-defs.h>
-void memcg1_update_tree(struct mem_cgroup *memcg, int nid);
void memcg1_remove_from_trees(struct mem_cgroup *memcg);
static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 11/14] mm: memcg: make memcg1_update_tree() static
2024-05-28 21:44 ` [PATCH v1 11/14] mm: memcg: make memcg1_update_tree() static Roman Gushchin
@ 2024-06-01 6:48 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:48 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 02:44:32PM GMT, Roman Gushchin wrote:
> memcg1_update_tree() is not used outside of mm/memcontrol-v1.c
> anymore, define it as static and remove the declaration from
> the header file.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 12/14] mm: memcg: group cgroup v1 memcg related declarations
2024-05-28 21:44 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Roman Gushchin
2024-05-28 21:44 ` [PATCH v1 11/14] mm: memcg: make memcg1_update_tree() static Roman Gushchin
@ 2024-05-28 21:44 ` Roman Gushchin
2024-06-01 6:49 ` Shakeel Butt
2024-05-28 21:44 ` [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option Roman Gushchin
` (2 subsequent siblings)
4 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 21:44 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Group all cgroup v1-related declarations at the end of memcontrol.h
and mm/memcontrol-v1.h with an intention to put them all together
under a config option later on. It should make things easier to
follow and maintain too.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
include/linux/memcontrol.h | 144 +++++++++++++++++++------------------
mm/memcontrol-v1.h | 89 ++++++++++++-----------
2 files changed, 123 insertions(+), 110 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 394b92b620d9c..7474b20a5d3f5 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -944,39 +944,13 @@ static inline void mem_cgroup_exit_user_fault(void)
current->in_user_fault = 0;
}
-static inline bool task_in_memcg_oom(struct task_struct *p)
-{
- return p->memcg_in_oom;
-}
-
-bool mem_cgroup_oom_synchronize(bool wait);
struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
struct mem_cgroup *oom_domain);
void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);
-void folio_memcg_lock(struct folio *folio);
-void folio_memcg_unlock(struct folio *folio);
-
void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
int val);
-/* try to stablize folio_memcg() for all the pages in a memcg */
-static inline bool mem_cgroup_trylock_pages(struct mem_cgroup *memcg)
-{
- rcu_read_lock();
-
- if (mem_cgroup_disabled() || !atomic_read(&memcg->moving_account))
- return true;
-
- rcu_read_unlock();
- return false;
-}
-
-static inline void mem_cgroup_unlock_pages(void)
-{
- rcu_read_unlock();
-}
-
/* idx can be of type enum memcg_stat_item or node_stat_item */
static inline void mod_memcg_state(struct mem_cgroup *memcg,
enum memcg_stat_item idx, int val)
@@ -1103,10 +1077,6 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
void split_page_memcg(struct page *head, int old_order, int new_order);
-unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
- gfp_t gfp_mask,
- unsigned long *total_scanned);
-
#else /* CONFIG_MEMCG */
#define MEM_CGROUP_ID_SHIFT 0
@@ -1417,26 +1387,6 @@ mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
{
}
-static inline void folio_memcg_lock(struct folio *folio)
-{
-}
-
-static inline void folio_memcg_unlock(struct folio *folio)
-{
-}
-
-static inline bool mem_cgroup_trylock_pages(struct mem_cgroup *memcg)
-{
- /* to match folio_memcg_rcu() */
- rcu_read_lock();
- return true;
-}
-
-static inline void mem_cgroup_unlock_pages(void)
-{
- rcu_read_unlock();
-}
-
static inline void mem_cgroup_handle_over_high(gfp_t gfp_mask)
{
}
@@ -1449,16 +1399,6 @@ static inline void mem_cgroup_exit_user_fault(void)
{
}
-static inline bool task_in_memcg_oom(struct task_struct *p)
-{
- return false;
-}
-
-static inline bool mem_cgroup_oom_synchronize(bool wait)
-{
- return false;
-}
-
static inline struct mem_cgroup *mem_cgroup_get_oom_group(
struct task_struct *victim, struct mem_cgroup *oom_domain)
{
@@ -1552,14 +1492,6 @@ void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
static inline void split_page_memcg(struct page *head, int old_order, int new_order)
{
}
-
-static inline
-unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
- gfp_t gfp_mask,
- unsigned long *total_scanned)
-{
- return 0;
-}
#endif /* CONFIG_MEMCG */
/*
@@ -1910,4 +1842,80 @@ static inline bool mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg)
}
#endif
+
+/* Cgroup v1-related declarations */
+
+#ifdef CONFIG_MEMCG
+unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned);
+
+bool mem_cgroup_oom_synchronize(bool wait);
+
+static inline bool task_in_memcg_oom(struct task_struct *p)
+{
+ return p->memcg_in_oom;
+}
+
+void folio_memcg_lock(struct folio *folio);
+void folio_memcg_unlock(struct folio *folio);
+
+/* try to stablize folio_memcg() for all the pages in a memcg */
+static inline bool mem_cgroup_trylock_pages(struct mem_cgroup *memcg)
+{
+ rcu_read_lock();
+
+ if (mem_cgroup_disabled() || !atomic_read(&memcg->moving_account))
+ return true;
+
+ rcu_read_unlock();
+ return false;
+}
+
+static inline void mem_cgroup_unlock_pages(void)
+{
+ rcu_read_unlock();
+}
+
+#else /* CONFIG_MEMCG */
+static inline
+unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
+ gfp_t gfp_mask,
+ unsigned long *total_scanned)
+{
+ return 0;
+}
+
+static inline void folio_memcg_lock(struct folio *folio)
+{
+}
+
+static inline void folio_memcg_unlock(struct folio *folio)
+{
+}
+
+static inline bool mem_cgroup_trylock_pages(struct mem_cgroup *memcg)
+{
+ /* to match folio_memcg_rcu() */
+ rcu_read_lock();
+ return true;
+}
+
+static inline void mem_cgroup_unlock_pages(void)
+{
+ rcu_read_unlock();
+}
+
+static inline bool task_in_memcg_oom(struct task_struct *p)
+{
+ return false;
+}
+
+static inline bool mem_cgroup_oom_synchronize(bool wait)
+{
+ return false;
+}
+
+#endif /* CONFIG_MEMCG */
+
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 7d6ac4a4fb36d..89d4207930481 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -5,15 +5,9 @@
#include <linux/cgroup-defs.h>
-void memcg1_remove_from_trees(struct mem_cgroup *memcg);
-
-static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
-{
- WRITE_ONCE(memcg->soft_limit, PAGE_COUNTER_MAX);
-}
+/* Cgroup v1 and v2 common declarations */
void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages);
-void memcg1_check_events(struct mem_cgroup *memcg, int nid);
int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
unsigned int nr_pages);
@@ -29,30 +23,6 @@ static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n);
void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n);
-bool memcg1_wait_acct_move(struct mem_cgroup *memcg);
-struct cgroup_taskset;
-int memcg1_can_attach(struct cgroup_taskset *tset);
-void memcg1_cancel_attach(struct cgroup_taskset *tset);
-void memcg1_move_task(void);
-
-/*
- * Per memcg event counter is incremented at every pagein/pageout. With THP,
- * it will be incremented by the number of pages. This counter is used
- * to trigger some periodic events. This is straightforward and better
- * than using jiffies etc. to handle periodic memcg event.
- */
-enum mem_cgroup_events_target {
- MEM_CGROUP_TARGET_THRESH,
- MEM_CGROUP_TARGET_SOFTLIMIT,
- MEM_CGROUP_NTARGETS,
-};
-
-/* Whether legacy memory+swap accounting is active */
-static bool do_memsw_account(void)
-{
- return !cgroup_subsys_on_dfl(memory_cgrp_subsys);
-}
-
/*
* Iteration constructs for visiting all cgroups (under a tree). If
* loops are exited prematurely (break), mem_cgroup_iter_break() must
@@ -68,24 +38,28 @@ static bool do_memsw_account(void)
iter != NULL; \
iter = mem_cgroup_iter(NULL, iter, NULL))
-void memcg1_css_offline(struct mem_cgroup *memcg);
+/* Whether legacy memory+swap accounting is active */
+static bool do_memsw_account(void)
+{
+ return !cgroup_subsys_on_dfl(memory_cgrp_subsys);
+}
-/* for encoding cft->private value on file */
-enum res_type {
- _MEM,
- _MEMSWAP,
- _KMEM,
- _TCP,
+/*
+ * Per memcg event counter is incremented at every pagein/pageout. With THP,
+ * it will be incremented by the number of pages. This counter is used
+ * to trigger some periodic events. This is straightforward and better
+ * than using jiffies etc. to handle periodic memcg event.
+ */
+enum mem_cgroup_events_target {
+ MEM_CGROUP_TARGET_THRESH,
+ MEM_CGROUP_TARGET_SOFTLIMIT,
+ MEM_CGROUP_NTARGETS,
};
bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
enum mem_cgroup_events_target target);
unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap);
-bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked);
-void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked);
-void memcg1_oom_recover(struct mem_cgroup *memcg);
-
void drain_all_stock(struct mem_cgroup *root_memcg);
unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
unsigned int lru_mask, bool tree);
@@ -100,6 +74,37 @@ unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item);
unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item);
int memory_stat_show(struct seq_file *m, void *v);
+/* Cgroup v1-specific declarations */
+
+void memcg1_remove_from_trees(struct mem_cgroup *memcg);
+
+static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
+{
+ WRITE_ONCE(memcg->soft_limit, PAGE_COUNTER_MAX);
+}
+
+bool memcg1_wait_acct_move(struct mem_cgroup *memcg);
+
+struct cgroup_taskset;
+int memcg1_can_attach(struct cgroup_taskset *tset);
+void memcg1_cancel_attach(struct cgroup_taskset *tset);
+void memcg1_move_task(void);
+void memcg1_css_offline(struct mem_cgroup *memcg);
+
+/* for encoding cft->private value on file */
+enum res_type {
+ _MEM,
+ _MEMSWAP,
+ _KMEM,
+ _TCP,
+};
+
+bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked);
+void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked);
+void memcg1_oom_recover(struct mem_cgroup *memcg);
+
+void memcg1_check_events(struct mem_cgroup *memcg, int nid);
+
void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
extern struct cftype memsw_files[];
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 12/14] mm: memcg: group cgroup v1 memcg related declarations
2024-05-28 21:44 ` [PATCH v1 12/14] mm: memcg: group cgroup v1 memcg related declarations Roman Gushchin
@ 2024-06-01 6:49 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:49 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 02:44:33PM GMT, Roman Gushchin wrote:
> Group all cgroup v1-related declarations at the end of memcontrol.h
> and mm/memcontrol-v1.h with an intention to put them all together
> under a config option later on. It should make things easier to
> follow and maintain too.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option
2024-05-28 21:44 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Roman Gushchin
2024-05-28 21:44 ` [PATCH v1 11/14] mm: memcg: make memcg1_update_tree() static Roman Gushchin
2024-05-28 21:44 ` [PATCH v1 12/14] mm: memcg: group cgroup v1 memcg related declarations Roman Gushchin
@ 2024-05-28 21:44 ` Roman Gushchin
2024-06-01 6:51 ` Shakeel Butt
2024-06-02 12:00 ` Lance Yang
2024-05-28 21:44 ` [PATCH v1 14/14] MAINTAINERS: add mm/memcontrol-v1.c/h to the list of maintained files Roman Gushchin
2024-06-01 6:48 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Shakeel Butt
4 siblings, 2 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 21:44 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Guard cgroup v1-related members of task_struct under the CONFIG_MEMCG_V1
config option, so that users who adopted cgroup v2 don't have to waste
the memory for fields which are never accessed.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
include/linux/memcontrol.h | 2 +-
init/Kconfig | 9 +++++++++
mm/Makefile | 3 ++-
mm/memcontrol-v1.h | 21 ++++++++++++++++++++-
mm/memcontrol.c | 10 +++++++---
5 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 7474b20a5d3f5..aaa97ec0634f7 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1845,7 +1845,7 @@ static inline bool mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg)
/* Cgroup v1-related declarations */
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MEMCG_V1
unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
gfp_t gfp_mask,
unsigned long *total_scanned);
diff --git a/init/Kconfig b/init/Kconfig
index febdea2afc3be..5191b6435b4e7 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -969,6 +969,15 @@ config MEMCG
help
Provides control over the memory footprint of tasks in a cgroup.
+config MEMCG_V1
+ bool "Legacy memory controller"
+ depends on MEMCG
+ default n
+ help
+ Legacy cgroup v1 memory controller.
+
+ San N is unsure.
+
config MEMCG_KMEM
bool
depends on MEMCG
diff --git a/mm/Makefile b/mm/Makefile
index 124d4dea20351..d2915f8c9dc01 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -96,7 +96,8 @@ obj-$(CONFIG_NUMA) += memory-tiers.o
obj-$(CONFIG_DEVICE_MIGRATION) += migrate_device.o
obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o
obj-$(CONFIG_PAGE_COUNTER) += page_counter.o
-obj-$(CONFIG_MEMCG) += memcontrol.o memcontrol-v1.o vmpressure.o
+obj-$(CONFIG_MEMCG_V1) += memcontrol-v1.o
+obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o
ifdef CONFIG_SWAP
obj-$(CONFIG_MEMCG) += swap_cgroup.o
endif
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 89d4207930481..64b053d7f131e 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -75,7 +75,7 @@ unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item);
int memory_stat_show(struct seq_file *m, void *v);
/* Cgroup v1-specific declarations */
-
+#ifdef CONFIG_MEMCG_V1
void memcg1_remove_from_trees(struct mem_cgroup *memcg);
static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
@@ -110,4 +110,23 @@ void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
extern struct cftype memsw_files[];
extern struct cftype mem_cgroup_legacy_files[];
+#else /* CONFIG_MEMCG_V1 */
+
+static inline void memcg1_remove_from_trees(struct mem_cgroup *memcg) {}
+static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg) {}
+static inline bool memcg1_wait_acct_move(struct mem_cgroup *memcg) { return false; }
+static inline void memcg1_css_offline(struct mem_cgroup *memcg) {}
+
+static inline bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked) { return true; }
+static inline void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked) {}
+static inline void memcg1_oom_recover(struct mem_cgroup *memcg) {}
+
+static inline void memcg1_check_events(struct mem_cgroup *memcg, int nid) {}
+
+static inline void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) {}
+
+extern struct cftype memsw_files[];
+extern struct cftype mem_cgroup_legacy_files[];
+#endif /* CONFIG_MEMCG_V1 */
+
#endif /* __MM_MEMCONTROL_V1_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8a28ba4ca93ea..8cbceeb9c7ac4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4473,18 +4473,20 @@ struct cgroup_subsys memory_cgrp_subsys = {
.css_free = mem_cgroup_css_free,
.css_reset = mem_cgroup_css_reset,
.css_rstat_flush = mem_cgroup_css_rstat_flush,
- .can_attach = memcg1_can_attach,
#if defined(CONFIG_LRU_GEN) || defined(CONFIG_MEMCG_KMEM)
.attach = mem_cgroup_attach,
#endif
- .cancel_attach = memcg1_cancel_attach,
- .post_attach = memcg1_move_task,
#ifdef CONFIG_MEMCG_KMEM
.fork = mem_cgroup_fork,
.exit = mem_cgroup_exit,
#endif
.dfl_cftypes = memory_files,
+#ifdef CONFIG_MEMCG_V1
+ .can_attach = memcg1_can_attach,
+ .cancel_attach = memcg1_cancel_attach,
+ .post_attach = memcg1_move_task,
.legacy_cftypes = mem_cgroup_legacy_files,
+#endif
.early_init = 0,
};
@@ -5655,7 +5657,9 @@ static int __init mem_cgroup_swap_init(void)
return 0;
WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files));
+#ifdef CONFIG_MEMCG_V1
WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files));
+#endif
#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, zswap_files));
#endif
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option
2024-05-28 21:44 ` [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option Roman Gushchin
@ 2024-06-01 6:51 ` Shakeel Butt
2024-06-02 12:00 ` Lance Yang
1 sibling, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:51 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 02:44:34PM GMT, Roman Gushchin wrote:
> Guard cgroup v1-related members of task_struct under the CONFIG_MEMCG_V1
> config option, so that users who adopted cgroup v2 don't have to waste
> the memory for fields which are never accessed.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option
2024-05-28 21:44 ` [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option Roman Gushchin
2024-06-01 6:51 ` Shakeel Butt
@ 2024-06-02 12:00 ` Lance Yang
2024-06-03 19:13 ` Roman Gushchin
1 sibling, 1 reply; 40+ messages in thread
From: Lance Yang @ 2024-06-02 12:00 UTC (permalink / raw)
To: roman.gushchin
Cc: akpm, hannes, linux-kernel, linux-mm, mhocko, muchun.song,
shakeel.butt, willy, Lance Yang
Hi Roman,
I noticed that you changed '#ifdef CONFIG_MEMCG' to '#ifdef CONFIG_MEMCG_V1'.
However, it seems like the comments for the corresponding #else and #endif were
not updated accordingly.
It might be something like:
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index ba55ebd15354..796cfa842346 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1883,7 +1883,7 @@ static inline void mem_cgroup_unlock_pages(void)
rcu_read_unlock();
}
-#else /* CONFIG_MEMCG */
+#else /* CONFIG_MEMCG_V1 */
static inline
unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
gfp_t gfp_mask,
@@ -1922,6 +1922,6 @@ static inline bool mem_cgroup_oom_synchronize(bool wait)
return false;
}
-#endif /* CONFIG_MEMCG */
+#endif /* CONFIG_MEMCG_V1 */
#endif /* _LINUX_MEMCONTROL_H */
---
Thanks,
Lance
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option
2024-06-02 12:00 ` Lance Yang
@ 2024-06-03 19:13 ` Roman Gushchin
0 siblings, 0 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-06-03 19:13 UTC (permalink / raw)
To: Lance Yang
Cc: akpm, hannes, linux-kernel, linux-mm, mhocko, muchun.song,
shakeel.butt, willy
On Sun, Jun 02, 2024 at 08:00:04PM +0800, Lance Yang wrote:
> Hi Roman,
>
> I noticed that you changed '#ifdef CONFIG_MEMCG' to '#ifdef CONFIG_MEMCG_V1'.
> However, it seems like the comments for the corresponding #else and #endif were
> not updated accordingly.
Hi Lance!
Good catch, thank you!
I gonna update the patch, if there will be another version.
Otherwise I hope Andrew can pick your change as a fixlet.
Thanks!
>
> It might be something like:
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index ba55ebd15354..796cfa842346 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1883,7 +1883,7 @@ static inline void mem_cgroup_unlock_pages(void)
> rcu_read_unlock();
> }
>
> -#else /* CONFIG_MEMCG */
> +#else /* CONFIG_MEMCG_V1 */
> static inline
> unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,
> gfp_t gfp_mask,
> @@ -1922,6 +1922,6 @@ static inline bool mem_cgroup_oom_synchronize(bool wait)
> return false;
> }
>
> -#endif /* CONFIG_MEMCG */
> +#endif /* CONFIG_MEMCG_V1 */
>
> #endif /* _LINUX_MEMCONTROL_H */
> ---
>
> Thanks,
> Lance
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH v1 14/14] MAINTAINERS: add mm/memcontrol-v1.c/h to the list of maintained files
2024-05-28 21:44 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Roman Gushchin
` (2 preceding siblings ...)
2024-05-28 21:44 ` [PATCH v1 13/14] mm: memcg: put cgroup v1-related members of task_struct under config option Roman Gushchin
@ 2024-05-28 21:44 ` Roman Gushchin
2024-06-01 6:53 ` Shakeel Butt
2024-06-01 6:48 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Shakeel Butt
4 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-05-28 21:44 UTC (permalink / raw)
To: Andrew Morton
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel, Roman Gushchin
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
MAINTAINERS | 2 ++
1 file changed, 2 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 7af431daf77bc..cccaf2bcedecd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5584,6 +5584,8 @@ L: linux-mm@kvack.org
S: Maintained
F: include/linux/memcontrol.h
F: mm/memcontrol.c
+F: mm/memcontrol-v1.c
+F: mm/memcontrol-v1.h
F: mm/swap_cgroup.c
F: samples/cgroup/*
F: tools/testing/selftests/cgroup/memcg_protection.m
--
2.45.1
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 14/14] MAINTAINERS: add mm/memcontrol-v1.c/h to the list of maintained files
2024-05-28 21:44 ` [PATCH v1 14/14] MAINTAINERS: add mm/memcontrol-v1.c/h to the list of maintained files Roman Gushchin
@ 2024-06-01 6:53 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:53 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 02:44:35PM GMT, Roman Gushchin wrote:
Nit: add a simple commit message even if it is redundant.
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c
2024-05-28 21:44 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Roman Gushchin
` (3 preceding siblings ...)
2024-05-28 21:44 ` [PATCH v1 14/14] MAINTAINERS: add mm/memcontrol-v1.c/h to the list of maintained files Roman Gushchin
@ 2024-06-01 6:48 ` Shakeel Butt
4 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-01 6:48 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Tue, May 28, 2024 at 02:44:31PM GMT, Roman Gushchin wrote:
> Move legacy cgroup v1 memory controller interfaces and corresponding
> code into memcontrol-v1.c.
>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (9 preceding siblings ...)
2024-05-28 21:44 ` [PATCH v1 10/14] mm: memcg: move cgroup v1 interface files to memcontrol-v1.c Roman Gushchin
@ 2024-06-03 19:34 ` Roman Gushchin
2024-06-07 15:29 ` Shakeel Butt
11 siblings, 0 replies; 40+ messages in thread
From: Roman Gushchin @ 2024-06-03 19:34 UTC (permalink / raw)
To: Andrew Morton, Johannes Weiner, Michal Hocko
Cc: Muchun Song, Johannes Weiner, Michal Hocko, Shakeel Butt,
Matthew Wilcox, linux-mm, linux-kernel
Johannes, Michal,
friendly ping. Do you have any concerns regarding this patchset?
There is a number of things which can/need to be improved/polished on top,
but I'd really like to land this one first, because rebasing of
such a massive patchset is time-consuming and might also introduce
some silly bugs.
Thanks
On Tue, May 28, 2024 at 01:20:52PM -0700, Roman Gushchin wrote:
> Cgroups v2 have been around for a while and many users have fully adopted them,
> so they never use cgroups v1 features and functionality. Yet they have to "pay"
> for the cgroup v1 support anyway:
> 1) the kernel binary contains an unused cgroup v1 code,
> 2) some code paths have additional checks which are not needed,
> 3) some common structures like task_struct and mem_cgroup contain unused
> cgroup v1-specific members.
>
> Cgroup v1's memory controller has a number of features that are not supported
> by cgroup v2 and their implementation is pretty much self contained.
> Most notably, these features are: soft limit reclaim, oom handling in userspace,
> complicated event notification system, charge migration. Cgroup v1-specific code
> in memcontrol.c is close to 4k lines in size and it's intervened with generic
> and cgroup v2-specific code. It's a burden on developers and maintainers.
>
> This patchset aims to solve these problems by:
> 1) moving cgroup v1-specific memcg code to the new mm/memcontrol-v1.c file,
> 2) putting definitions shared by memcontrol.c and memcontrol-v1.c into the
> mm/memcontrol-v1.h header,
> 3) introducing the CONFIG_MEMCG_V1 config option, turned off by default,
> 4) making memcontrol-v1.c to compile only if CONFIG_MEMCG_V1 is set.
>
> If CONFIG_MEMCG_V1 is not set, cgroup v1 memory controller is still available
> for mounting, however no memory-specific control knobs are present.
>
> This patchset is based against mm-unstable tree (b610f75d19a34),
> however a version based on mm-stable can be found here:
> https://github.com/rgushchin/linux/tree/memcontrol_v1.1-stable .
>
> rfc:
> https://lwn.net/Articles/973082/
>
> v1:
> - switched to CONFIG_MEMCG_V1 being off by default based on LSFMMBPF
> discussion [1]
> - switched to memcg1_ prefix (Johannes)
> - many minor fixes
> - dropped patches which put struct memcg members under CONFIG_MEMCG_V1
> (will post as a separate patchset)
>
> [1]: https://lwn.net/Articles/974575/
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option
2024-05-28 20:20 [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
` (10 preceding siblings ...)
2024-06-03 19:34 ` [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option Roman Gushchin
@ 2024-06-07 15:29 ` Shakeel Butt
2024-06-07 16:13 ` Roman Gushchin
11 siblings, 1 reply; 40+ messages in thread
From: Shakeel Butt @ 2024-06-07 15:29 UTC (permalink / raw)
To: Andrew Morton
Cc: Roman Gushchin, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
Hi Andrew, can you please add this series to the mm-unstable? Roman and I
plan to add more stuff based on this series, so it would be good to get
some exposure for this series.
Thanks,
Shakeel
On Tue, May 28, 2024 at 01:20:52PM GMT, Roman Gushchin wrote:
> Cgroups v2 have been around for a while and many users have fully adopted them,
> so they never use cgroups v1 features and functionality. Yet they have to "pay"
> for the cgroup v1 support anyway:
> 1) the kernel binary contains an unused cgroup v1 code,
> 2) some code paths have additional checks which are not needed,
> 3) some common structures like task_struct and mem_cgroup contain unused
> cgroup v1-specific members.
>
> Cgroup v1's memory controller has a number of features that are not supported
> by cgroup v2 and their implementation is pretty much self contained.
> Most notably, these features are: soft limit reclaim, oom handling in userspace,
> complicated event notification system, charge migration. Cgroup v1-specific code
> in memcontrol.c is close to 4k lines in size and it's intervened with generic
> and cgroup v2-specific code. It's a burden on developers and maintainers.
>
> This patchset aims to solve these problems by:
> 1) moving cgroup v1-specific memcg code to the new mm/memcontrol-v1.c file,
> 2) putting definitions shared by memcontrol.c and memcontrol-v1.c into the
> mm/memcontrol-v1.h header,
> 3) introducing the CONFIG_MEMCG_V1 config option, turned off by default,
> 4) making memcontrol-v1.c to compile only if CONFIG_MEMCG_V1 is set.
>
> If CONFIG_MEMCG_V1 is not set, cgroup v1 memory controller is still available
> for mounting, however no memory-specific control knobs are present.
>
> This patchset is based against mm-unstable tree (b610f75d19a34),
> however a version based on mm-stable can be found here:
> https://github.com/rgushchin/linux/tree/memcontrol_v1.1-stable .
>
> rfc:
> https://lwn.net/Articles/973082/
>
> v1:
> - switched to CONFIG_MEMCG_V1 being off by default based on LSFMMBPF
> discussion [1]
> - switched to memcg1_ prefix (Johannes)
> - many minor fixes
> - dropped patches which put struct memcg members under CONFIG_MEMCG_V1
> (will post as a separate patchset)
>
> [1]: https://lwn.net/Articles/974575/
>
> MAINTAINERS | 2 +
> include/linux/memcontrol.h | 156 ++++---
> init/Kconfig | 9 +
> mm/Makefile | 2 +
> mm/memcontrol-v1.c | 2933 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> mm/memcontrol-v1.h | 132 ++++++
> mm/memcontrol.c | 4169 +++++++++++++++++++++++++++---------------------------------------------------------------------------------------------------------------------------------------------------
> mm/vmscan.c | 10 +-
> 8 files changed, 3794 insertions(+), 3619 deletions(-)
>
> Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
>
>
> Roman Gushchin (14):
> mm: memcg: introduce memcontrol-v1.c
> mm: memcg: move soft limit reclaim code to memcontrol-v1.c
> mm: memcg: rename soft limit reclaim-related functions
> mm: memcg: move charge migration code to memcontrol-v1.c
> mm: memcg: rename charge move-related functions
> mm: memcg: move legacy memcg event code into memcontrol-v1.c
> mm: memcg: rename memcg_check_events()
> mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c
> mm: memcg: rename memcg_oom_recover()
> mm: memcg: move cgroup v1 interface files to memcontrol-v1.c
> mm: memcg: make memcg1_update_tree() static
> mm: memcg: group cgroup v1 memcg related declarations
> mm: memcg: put cgroup v1-related members of task_struct under config
> option
> MAINTAINERS: add mm/memcontrol-v1.c/h to the list of maintained files
>
> MAINTAINERS | 2 +
> include/linux/memcontrol.h | 156 +-
> init/Kconfig | 9 +
> mm/Makefile | 2 +
> mm/memcontrol-v1.c | 2933 +++++++++++++++++++++++++
> mm/memcontrol-v1.h | 132 ++
> mm/memcontrol.c | 4141 ++++++------------------------------
> mm/vmscan.c | 10 +-
> 8 files changed, 3780 insertions(+), 3605 deletions(-)
> create mode 100644 mm/memcontrol-v1.c
> create mode 100644 mm/memcontrol-v1.h
>
> --
> 2.45.1
>
^ permalink raw reply [flat|nested] 40+ messages in thread* Re: [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option
2024-06-07 15:29 ` Shakeel Butt
@ 2024-06-07 16:13 ` Roman Gushchin
2024-06-24 22:00 ` Shakeel Butt
0 siblings, 1 reply; 40+ messages in thread
From: Roman Gushchin @ 2024-06-07 16:13 UTC (permalink / raw)
To: Shakeel Butt
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Fri, Jun 07, 2024 at 08:29:20AM -0700, Shakeel Butt wrote:
> Hi Andrew, can you please add this series to the mm-unstable? Roman and I
> plan to add more stuff based on this series, so it would be good to get
> some exposure for this series.
I've a v2 with 2 minor fixes (compilation issue with !CONFIG_MMU and a small
comments fix). I can rebase it on top of the current mm-unstable and post, please,
let me know when it's a good moment to do it.
Thanks!
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH v1 00/14] mm: memcg: separate legacy cgroup v1 code and put under config option
2024-06-07 16:13 ` Roman Gushchin
@ 2024-06-24 22:00 ` Shakeel Butt
0 siblings, 0 replies; 40+ messages in thread
From: Shakeel Butt @ 2024-06-24 22:00 UTC (permalink / raw)
To: Roman Gushchin
Cc: Andrew Morton, Muchun Song, Johannes Weiner, Michal Hocko,
Matthew Wilcox, linux-mm, linux-kernel
On Fri, Jun 07, 2024 at 09:13:46AM GMT, Roman Gushchin wrote:
> On Fri, Jun 07, 2024 at 08:29:20AM -0700, Shakeel Butt wrote:
> > Hi Andrew, can you please add this series to the mm-unstable? Roman and I
> > plan to add more stuff based on this series, so it would be good to get
> > some exposure for this series.
>
> I've a v2 with 2 minor fixes (compilation issue with !CONFIG_MMU and a small
> comments fix). I can rebase it on top of the current mm-unstable and post, please,
> let me know when it's a good moment to do it.
>
Please post the v2. I think we are already late for the next window but
let's request Andrew to add this to mm-unstable for the follow up planned
work.
Shakeel
^ permalink raw reply [flat|nested] 40+ messages in thread