[Devel] [PATCH RH9 18/23] ms/memcg: enable accounting for posix_timers_cache slab

[Vasily Averin]

A program may create multiple interval timers using timer_create().  For
each timer the kernel preallocates a "queued real-time signal",
Consequently, the number of timers is limited by the RLIMIT_SIGPENDING
resource limit.  The allocated object is quite small, ~250 bytes, but even
the default signal limits allow to consume up to 100 megabytes per user.

It makes sense to account for them to limit the host's memory consumption
from inside the memcg-limited container.

Link: https://lkml.kernel.org/r/57795560-025c-267c-6b1a-dea852d95530@virtuozzo.com
Signed-off-by: Vasily Averin <vvs at virtuozzo.com>
Reviewed-by: Thomas Gleixner <tglx at linutronix.de>
Reviewed-by: Shakeel Butt <shakeelb at google.com>
Cc: Alexander Viro <viro at zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan at gmail.com>
Cc: Andrei Vagin <avagin at gmail.com>
Cc: Borislav Petkov <bp at alien8.de>
Cc: Borislav Petkov <bp at suse.de>
Cc: Christian Brauner <christian.brauner at ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46 at gmail.com>
Cc: "Eric W. Biederman" <ebiederm at xmission.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa at zytor.com>
Cc: Ingo Molnar <mingo at redhat.com>
Cc: "J. Bruce Fields" <bfields at fieldses.org>
Cc: Jeff Layton <jlayton at kernel.org>
Cc: Jens Axboe <axboe at kernel.dk>
Cc: Jiri Slaby <jirislaby at kernel.org>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Kirill Tkhai <ktkhai at virtuozzo.com>
Cc: Michal Hocko <mhocko at kernel.org>
Cc: Oleg Nesterov <oleg at redhat.com>
Cc: Roman Gushchin <guro at fb.com>
Cc: Serge Hallyn <serge at hallyn.com>
Cc: Tejun Heo <tj at kernel.org>
Cc: Vladimir Davydov <vdavydov.dev at gmail.com>
Cc: Yutian Yang <nglaive at gmail.com>
Cc: Zefan Li <lizefan.x at bytedance.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
(cherry picked from commit c509723ec27e925bb91a20682c448e95d4bc8c9f)
https://jira.sw.ru/browse/PSBM-133990
Signed-off-by: Vasily Averin <vvs at virtuozzo.com>
---
 kernel/time/posix-timers.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index dd5697d7347b..7363f81dc31a 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -273,8 +273,8 @@ static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
 static __init int init_posix_timers(void)
 {
 	posix_timers_cache = kmem_cache_create("posix_timers_cache",
-					sizeof (struct k_itimer), 0, SLAB_PANIC,
-					NULL);
+					sizeof(struct k_itimer), 0,
+					SLAB_PANIC | SLAB_ACCOUNT, NULL);
 	return 0;
 }
 __initcall(init_posix_timers);
-- 
2.25.1