From: Vladimir Davydov <vdavydov@parallels.com>
To: akpm@linux-foundation.org
Cc: hannes@cmpxchg.org, mhocko@suse.cz, glommer@gmail.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
devel@openvz.org, Frederic Weisbecker <fweisbec@redhat.com>
Subject: [PATCH RESEND -mm 09/12] fork: do not charge thread_info to kmemcg
Date: Thu, 13 Mar 2014 19:06:47 +0400 [thread overview]
Message-ID: <75194ada8e572be8ecc11c81024a4948515fd5b1.1394708827.git.vdavydov@parallels.com> (raw)
In-Reply-To: <cover.1394708827.git.vdavydov@parallels.com>
This patch reverts 2ad306b17c0a ("fork: protect architectures where
THREAD_SIZE >= PAGE_SIZE against fork bombs").
The reasoning behind this is that charging thread_info is the last piece
that prevents us from reparenting kmemcg on css offline. The point is
that we can't reliably track all thread_info pages accounted to a
particular cgroup, because (a) it is freed in __put_task_struct and (b)
on exit tasks are moved to the root cgroup. That said, given a cgroup
there is no sane way to find all tasks (including zombies) that charged
thread_info to this cgroup. Of course, we could uncharge thread_info on
task exit, but that wouldn't help us against fork bombs. So revert and
forget about this.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
---
include/linux/thread_info.h | 2 --
kernel/fork.c | 4 ++--
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index fddbe2023a5d..1807bb194816 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -61,8 +61,6 @@ extern long do_no_restart_syscall(struct restart_block *parm);
# define THREADINFO_GFP (GFP_KERNEL | __GFP_NOTRACK)
#endif
-#define THREADINFO_GFP_ACCOUNTED (THREADINFO_GFP | __GFP_KMEMCG)
-
/*
* flag set/clear/test wrappers
* - pass TIF_xxxx constants to these functions
diff --git a/kernel/fork.c b/kernel/fork.c
index ea1bb6a54823..c22bdaa5db4e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -150,7 +150,7 @@ void __weak arch_release_thread_info(struct thread_info *ti)
static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
int node)
{
- struct page *page = alloc_pages_node(node, THREADINFO_GFP_ACCOUNTED,
+ struct page *page = alloc_pages_node(node, THREADINFO_GFP,
THREAD_SIZE_ORDER);
return page ? page_address(page) : NULL;
@@ -158,7 +158,7 @@ static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
static inline void free_thread_info(struct thread_info *ti)
{
- free_memcg_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
+ free_pages((unsigned long)ti, THREAD_SIZE_ORDER);
}
# else
static struct kmem_cache *thread_info_cache;
--
1.7.10.4
--
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next prev parent reply other threads:[~2014-03-13 15:07 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-13 15:06 [PATCH RESEND -mm 00/12] kmemcg reparenting Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 01/12] memcg: flush cache creation works before memcg cache destruction Vladimir Davydov
2014-03-17 16:07 ` Michal Hocko
2014-03-18 8:14 ` Vladimir Davydov
2014-03-18 8:55 ` Michal Hocko
2014-03-18 9:28 ` Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 02/12] memcg: fix race in memcg cache destruction path Vladimir Davydov
2014-03-17 16:42 ` Michal Hocko
2014-03-18 8:19 ` Vladimir Davydov
2014-03-18 10:01 ` Michal Hocko
2014-03-18 12:14 ` Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 03/12] memcg: fix root vs memcg cache destruction race Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 04/12] memcg: move slab caches list/mutex init to memcg creation Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 05/12] memcg: add pointer from memcg_cache_params to cache Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 06/12] memcg: keep all children of each root cache on a list Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 07/12] memcg: rework slab charging Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 08/12] memcg: do not charge kmalloc_large allocations Vladimir Davydov
2014-03-13 15:06 ` Vladimir Davydov [this message]
2014-03-13 15:06 ` [PATCH RESEND -mm 10/12] memcg: kill GFP_KMEMCG and stuff Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 11/12] memcg: reparent slab on css offline Vladimir Davydov
2014-03-13 15:06 ` [PATCH RESEND -mm 12/12] slub: make sure all memcg caches have unique names on sysfs Vladimir Davydov
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