From e94c8a9cbce1aee4af9e1285802785481b7f93c5 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Thu, 12 Jan 2012 17:18:20 -0800 Subject: memcg: make mem_cgroup_split_huge_fixup() more efficient In split_huge_page(), mem_cgroup_split_huge_fixup() is called to handle page_cgroup modifcations. It takes move_lock_page_cgroup() and modifies page_cgroup and LRU accounting jobs and called HPAGE_PMD_SIZE - 1 times. But thinking again, - compound_lock() is held at move_accout...then, it's not necessary to take move_lock_page_cgroup(). - LRU is locked and all tail pages will go into the same LRU as head is now on. - page_cgroup is contiguous in huge page range. This patch fixes mem_cgroup_split_huge_fixup() as to be called once per hugepage and reduce costs for spliting. [akpm@linux-foundation.org: fix typo, per Michal] Signed-off-by: KAMEZAWA Hiroyuki Cc: Johannes Weiner Cc: Andrea Arcangeli Reviewed-by: Michal Hocko Cc: Balbir Singh Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index e2f8e7caf04..cee3761666f 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -163,7 +163,7 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg); void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx); #ifdef CONFIG_TRANSPARENT_HUGEPAGE -void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail); +void mem_cgroup_split_huge_fixup(struct page *head); #endif #ifdef CONFIG_DEBUG_VM @@ -379,8 +379,7 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg) return 0; } -static inline void mem_cgroup_split_huge_fixup(struct page *head, - struct page *tail) +static inline void mem_cgroup_split_huge_fixup(struct page *head) { } -- cgit v1.2.3-70-g09d2