diff options
| author | Vladimir Davydov <vdavydov@virtuozzo.com> | 2015-12-11 13:40:24 -0800 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2016-06-08 11:09:39 +0800 |
| commit | 8193b24f337c58ca682b6f5bd71ba6bedbaf32ed (patch) | |
| tree | 7484be0237dec4407b076e18d62d7948373df5bf | |
| parent | c29dd233a2e4ff44fd9b59274f6cc44c24026d27 (diff) | |
memcg: fix memory.high target
When the memory.high threshold is exceeded, try_charge() schedules a
task_work to reclaim the excess. The reclaim target is set to the
number of pages requested by try_charge().
This is wrong, because try_charge() usually charges more pages than
requested (batch > nr_pages) in order to refill per cpu stocks. As a
result, a process in a cgroup can easily exceed memory.high
significantly when doing a lot of charges w/o returning to userspace
(e.g. reading a file in big chunks).
Fix this issue by assuring that when exceeding memory.high a process
reclaims as many pages as were actually charged (i.e. batch).
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 9516a18a9a253a94292e74f11f92083126c5a237)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
| -rw-r--r-- | mm/memcontrol.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6ef97d510f9e..b6ff19efb54e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2081,7 +2081,7 @@ done_restock: */ do { if (page_counter_read(&memcg->memory) > memcg->high) { - current->memcg_nr_pages_over_high += nr_pages; + current->memcg_nr_pages_over_high += batch; set_notify_resume(current); break; } |