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| author | Johannes Weiner <hannes@cmpxchg.org> | 2012-07-31 16:45:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-31 18:42:48 -0700 |
| commit | 24467cacc03cf8b156d4c6786697e5e5d13c9321 (patch) | |
| tree | d62344582c4b980226a65faa6ceefabb6d106204 /mm | |
| parent | 62ba7442c8e286b6dd68fe82a3cc85c9414d909b (diff) | |
| download | lwn-24467cacc03cf8b156d4c6786697e5e5d13c9321.tar.gz lwn-24467cacc03cf8b156d4c6786697e5e5d13c9321.zip | |
mm: memcg: remove needless !mm fixup to init_mm when charging
It does not matter to __mem_cgroup_try_charge() if the passed mm is NULL
or init_mm, it will charge the root memcg in either case.
Also fix up the comment in __mem_cgroup_try_charge() that claimed the
init_mm would be charged when no mm was passed. It's not really
incorrect, but confusing. Clarify that the root memcg is charged in this
case.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Wanpeng Li <liwp.linux@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 17a79e5ed688..10b370345a5b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2333,7 +2333,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, * We always charge the cgroup the mm_struct belongs to. * The mm_struct's mem_cgroup changes on task migration if the * thread group leader migrates. It's possible that mm is not - * set, if so charge the init_mm (happens for pagecache usage). + * set, if so charge the root memcg (happens for pagecache usage). */ if (!*ptr && !mm) *ptr = root_mem_cgroup; @@ -2833,8 +2833,6 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm, ret = 0; return ret; charge_cur_mm: - if (unlikely(!mm)) - mm = &init_mm; ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); if (ret == -EINTR) ret = 0; @@ -2899,9 +2897,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, if (PageCompound(page)) return 0; - if (unlikely(!mm)) - mm = &init_mm; - if (!PageSwapCache(page)) ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); else { /* page is swapcache/shmem */ |