From 24467cacc03cf8b156d4c6786697e5e5d13c9321 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Tue, 31 Jul 2012 16:45:40 -0700 Subject: 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 Acked-by: KAMEZAWA Hiroyuki Acked-by: Michal Hocko Cc: David Rientjes Cc: Hugh Dickins Cc: Johannes Weiner Cc: Wanpeng Li Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 17a79e5..10b3703 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 */ -- cgit v1.1