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| author | Oleg Nesterov <oleg@redhat.com> | 2014-06-04 16:07:54 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:54:03 -0700 |
| commit | 39af1765f1255b2bbadc3064e16270781abf24a1 (patch) | |
| tree | 55d8a858a7ab136314a397bebbd5bd72f0b0ee2b /kernel/exit.c | |
| parent | f87fb599ae4d2a152a93f9821b94f3158146d097 (diff) | |
| download | linux-stable-39af1765f1255b2bbadc3064e16270781abf24a1.tar.gz linux-stable-39af1765f1255b2bbadc3064e16270781abf24a1.tar.bz2 linux-stable-39af1765f1255b2bbadc3064e16270781abf24a1.zip | |
memcg: optimize the "Search everything else" loop in mm_update_next_owner()
for_each_process_thread() is sub-optimal. All threads share the same
->mm, we can swicth to the next process once we found a thread with
->mm != NULL and ->mm != mm.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Peter Chiang <pchiang@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 5ac3c19c245c..750c2e594617 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -397,9 +397,15 @@ retry: /* * Search through everything else, we should not get here often. */ - for_each_process_thread(g, c) { - if (!(c->flags & PF_KTHREAD) && c->mm == mm) - goto assign_new_owner; + for_each_process(g) { + if (g->flags & PF_KTHREAD) + continue; + for_each_thread(g, c) { + if (c->mm == mm) + goto assign_new_owner; + if (c->mm) + break; + } } read_unlock(&tasklist_lock); /* |