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| author | Sha Zhengju <handai.szj@taobao.com> | 2012-05-29 15:06:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-29 16:22:25 -0700 |
| commit | 748dad36d645f5c4517a115d60bb3a0e8f877ac0 (patch) | |
| tree | 0f3206a06c3d58b922535957083d5216467eddb9 /mm/memcontrol.c | |
| parent | a0db00fcf5da79911b7ff2db63ea7c0a5711e096 (diff) | |
| download | lwn-748dad36d645f5c4517a115d60bb3a0e8f877ac0.tar.gz lwn-748dad36d645f5c4517a115d60bb3a0e8f877ac0.zip | |
memcg: make threshold index in the right position
Index current_threshold may point to threshold that just equal to usage
after last call of __mem_cgroup_threshold. But after registering a new
event, it will change (pointing to threshold just below usage). So make
it consistent here.
For example:
now:
threshold array: 3 [5] 7 9 (usage = 6, [index] = 5)
next turn (after calling __mem_cgroup_threshold):
threshold array: 3 5 [7] 9 (usage = 7, [index] = 7)
after registering a new event (threshold = 10):
threshold array: 3 [5] 7 9 10 (usage = 7, [index] = 5)
Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 775b94b1b8bd..a8abf919c70a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -181,7 +181,7 @@ struct mem_cgroup_threshold { /* For threshold */ struct mem_cgroup_threshold_ary { - /* An array index points to threshold just below usage. */ + /* An array index points to threshold just below or equal to usage. */ int current_threshold; /* Size of entries[] */ unsigned int size; @@ -4280,7 +4280,7 @@ static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) usage = mem_cgroup_usage(memcg, swap); /* - * current_threshold points to threshold just below usage. + * current_threshold points to threshold just below or equal to usage. * If it's not true, a threshold was crossed after last * call of __mem_cgroup_threshold(). */ @@ -4406,14 +4406,15 @@ static int mem_cgroup_usage_register_event(struct cgroup *cgrp, /* Find current threshold */ new->current_threshold = -1; for (i = 0; i < size; i++) { - if (new->entries[i].threshold < usage) { + if (new->entries[i].threshold <= usage) { /* * new->current_threshold will not be used until * rcu_assign_pointer(), so it's safe to increment * it here. */ ++new->current_threshold; - } + } else + break; } /* Free old spare buffer and save old primary buffer as spare */ @@ -4482,7 +4483,7 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, continue; new->entries[j] = thresholds->primary->entries[i]; - if (new->entries[j].threshold < usage) { + if (new->entries[j].threshold <= usage) { /* * new->current_threshold will not be used * until rcu_assign_pointer(), so it's safe to increment |