From: Shakeel Butt <shakeel.butt@linux.dev>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Muchun Song <muchun.song@linux.dev>,
SeongJae Park <sj@kernel.org>,
Meta kernel team <kernel-team@meta.com>,
linux-mm@kvack.org, cgroups@vger.kernel.org,
damon@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH 6/8] mm/vmscan: use cgroup ID instead of private memcg ID in lru_gen interface
Date: Thu, 25 Dec 2025 15:21:14 -0800 [thread overview]
Message-ID: <20251225232116.294540-7-shakeel.butt@linux.dev> (raw)
In-Reply-To: <20251225232116.294540-1-shakeel.butt@linux.dev>
The LRU gen debugfs interface was using the internal private memcg ID
which is meant for tracking kernel objects that outlive their cgroup.
Switch to using the public cgroup ID instead.
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
---
mm/vmscan.c | 19 ++++++-------------
1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index a4b308a2f9ad..d78043c7e4af 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -5426,7 +5426,7 @@ static int lru_gen_seq_show(struct seq_file *m, void *v)
if (memcg)
cgroup_path(memcg->css.cgroup, m->private, PATH_MAX);
#endif
- seq_printf(m, "memcg %5hu %s\n", mem_cgroup_id(memcg), path);
+ seq_printf(m, "memcg %llu %s\n", mem_cgroup_ino(memcg), path);
}
seq_printf(m, " node %5d\n", nid);
@@ -5511,7 +5511,7 @@ static int run_eviction(struct lruvec *lruvec, unsigned long seq, struct scan_co
return -EINTR;
}
-static int run_cmd(char cmd, int memcg_id, int nid, unsigned long seq,
+static int run_cmd(char cmd, u64 memcg_id, int nid, unsigned long seq,
struct scan_control *sc, int swappiness, unsigned long opt)
{
struct lruvec *lruvec;
@@ -5522,19 +5522,12 @@ static int run_cmd(char cmd, int memcg_id, int nid, unsigned long seq,
return -EINVAL;
if (!mem_cgroup_disabled()) {
- rcu_read_lock();
-
- memcg = mem_cgroup_from_id(memcg_id);
- if (!mem_cgroup_tryget(memcg))
- memcg = NULL;
-
- rcu_read_unlock();
-
+ memcg = mem_cgroup_get_from_ino(memcg_id);
if (!memcg)
return -EINVAL;
}
- if (memcg_id != mem_cgroup_id(memcg))
+ if (memcg_id != mem_cgroup_ino(memcg))
goto done;
sc->target_mem_cgroup = memcg;
@@ -5601,7 +5594,7 @@ static ssize_t lru_gen_seq_write(struct file *file, const char __user *src,
int n;
int end;
char cmd, swap_string[5];
- unsigned int memcg_id;
+ u64 memcg_id;
unsigned int nid;
unsigned long seq;
unsigned int swappiness;
@@ -5611,7 +5604,7 @@ static ssize_t lru_gen_seq_write(struct file *file, const char __user *src,
if (!*cur)
continue;
- n = sscanf(cur, "%c %u %u %lu %n %4s %n %lu %n", &cmd, &memcg_id, &nid,
+ n = sscanf(cur, "%c %llu %u %lu %n %4s %n %lu %n", &cmd, &memcg_id, &nid,
&seq, &end, swap_string, &end, &opt, &end);
if (n < 4 || cur[end]) {
err = -EINVAL;
--
2.47.3
next prev parent reply other threads:[~2025-12-25 23:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-25 23:21 [PATCH 0/8] memcg: separate private and public ID namespaces Shakeel Butt
2025-12-25 23:21 ` [PATCH 1/8] memcg: introduce private id API for in-kernel users Shakeel Butt
2025-12-25 23:21 ` [PATCH 2/8] memcg: expose mem_cgroup_ino() and mem_cgroup_get_from_ino() unconditionally Shakeel Butt
2025-12-25 23:21 ` [PATCH 3/8] memcg: mem_cgroup_get_from_ino() returns NULL on error Shakeel Butt
2025-12-25 23:21 ` [PATCH 4/8] memcg: use cgroup_id() instead of cgroup_ino() for memcg ID Shakeel Butt
2025-12-25 23:21 ` [PATCH 5/8] mm/damon: use cgroup ID instead of private " Shakeel Butt
2025-12-26 18:23 ` SeongJae Park
2025-12-25 23:21 ` Shakeel Butt [this message]
2025-12-25 23:21 ` [PATCH 7/8] memcg: remove unused mem_cgroup_id() and mem_cgroup_from_id() Shakeel Butt
2025-12-25 23:21 ` [PATCH 8/8] memcg: rename mem_cgroup_ino() to mem_cgroup_id() Shakeel Butt
2025-12-26 12:31 ` kernel test robot
2025-12-27 22:12 ` SeongJae Park
2025-12-26 13:23 ` kernel test robot
2025-12-26 18:17 ` [PATCH 0/8] memcg: separate private and public ID namespaces SeongJae Park
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20251225232116.294540-7-shakeel.butt@linux.dev \
--to=shakeel.butt@linux.dev \
--cc=akpm@linux-foundation.org \
--cc=cgroups@vger.kernel.org \
--cc=damon@lists.linux.dev \
--cc=hannes@cmpxchg.org \
--cc=kernel-team@meta.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=muchun.song@linux.dev \
--cc=roman.gushchin@linux.dev \
--cc=sj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox