diff options
| author | Michal Hocko <mhocko@suse.cz> | 2012-12-13 01:52:23 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-13 05:38:35 +0400 |
| commit | c95d26c2ffd3931123d6a7a2489530ccbd36da7a (patch) | |
| tree | ad54b115b525c7956f85c2b0105bff055036e0e8 | |
| parent | 220f2ac91353dd8b239b70c4b4cf1615b80c1ff5 (diff) | |
| download | linux-c95d26c2ffd3931123d6a7a2489530ccbd36da7a.tar.xz | |
memcg: do not check for mm in __mem_cgroup_count_vm_event
The mm given to __mem_cgroup_count_vm_event() cannot be NULL because the
function is either called from the page fault path or vma->vm_mm is used.
So the check can be dropped.
The check was introduced by commit 456f998ec817 ("memcg: add the
pagefault count into memcg stats") because the originally proposed patch
used current->mm for shmem but this has been changed to vma->vm_mm later
on without the check being removed (thanks to Hugh for this
recollection).
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memcontrol.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7f0e3571df7e..6c055929c8cc 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1021,9 +1021,6 @@ void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) { struct mem_cgroup *memcg; - if (!mm) - return; - rcu_read_lock(); memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); if (unlikely(!memcg)) |