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| author | Hugh Dickins <hughd@google.com> | 2014-01-23 15:53:32 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-23 16:36:53 -0800 |
| commit | d8ad30559715ce97afb7d1a93a12fd90e8fff312 (patch) | |
| tree | de34c8716415741701e60981b89cfeb2aef114da | |
| parent | d2ab70aaae74456ed608740915dc82ef52291f69 (diff) | |
| download | op-kernel-dev-d8ad30559715ce97afb7d1a93a12fd90e8fff312.zip op-kernel-dev-d8ad30559715ce97afb7d1a93a12fd90e8fff312.tar.gz | |
mm/memcg: iteration skip memcgs not yet fully initialized
It is surprising that the mem_cgroup iterator can return memcgs which
have not yet been fully initialized. By accident (or trial and error?)
this appears not to present an actual problem; but it may be better to
prevent such surprises, by skipping memcgs not yet online.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org> [3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memcontrol.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index aa66cc4..9537e13 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1119,10 +1119,8 @@ skip_node: * protected by css_get and the tree walk is rcu safe. */ if (next_css) { - struct mem_cgroup *mem = mem_cgroup_from_css(next_css); - - if (css_tryget(&mem->css)) - return mem; + if ((next_css->flags & CSS_ONLINE) && css_tryget(next_css)) + return mem_cgroup_from_css(next_css); else { prev_css = next_css; goto skip_node; |
