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Commit 3eae90c3 authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
Browse files

memcg: remove redundant function calls 



remove_list/add_list uses page_cgroup_zoneinfo() in it.

So, it's called twice before and after lock.

	mz = page_cgroup_zoneinfo();
	lock();
	mz = page_cgroup_zoneinfo();
	....
	unlock();

And address of mz never changes.

This is not good. This patch fixes this behavior.

Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 29f2a4da

mm/memcontrol.c

+8 −8
Original line number Diff line number Diff line
@@ -275,10 +275,10 @@ static void unlock_page_cgroup(struct page *page) 
	bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);

}



static void __mem_cgroup_remove_list(struct page_cgroup *pc)

static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz,

			struct page_cgroup *pc)

{

	int from = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;

	struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);



	if (from)

		MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_ACTIVE) -= 1;
@@ -289,10 +289,10 @@ static void __mem_cgroup_remove_list(struct page_cgroup *pc) 
	list_del_init(&pc->lru);

}



static void __mem_cgroup_add_list(struct page_cgroup *pc)

static void __mem_cgroup_add_list(struct mem_cgroup_per_zone *mz,

				struct page_cgroup *pc)

{

	int to = pc->flags & PAGE_CGROUP_FLAG_ACTIVE;

	struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);



	if (!to) {

		MEM_CGROUP_ZSTAT(mz, MEM_CGROUP_ZSTAT_INACTIVE) += 1;
@@ -618,7 +618,7 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, 


	mz = page_cgroup_zoneinfo(pc);

	spin_lock_irqsave(&mz->lru_lock, flags);

	__mem_cgroup_add_list(pc);

	__mem_cgroup_add_list(mz, pc);

	spin_unlock_irqrestore(&mz->lru_lock, flags);



	unlock_page_cgroup(page);
@@ -674,7 +674,7 @@ void mem_cgroup_uncharge_page(struct page *page) 
	if (--(pc->ref_cnt) == 0) {

		mz = page_cgroup_zoneinfo(pc);

		spin_lock_irqsave(&mz->lru_lock, flags);

		__mem_cgroup_remove_list(pc);

		__mem_cgroup_remove_list(mz, pc);

		spin_unlock_irqrestore(&mz->lru_lock, flags);



		page_assign_page_cgroup(page, NULL);
@@ -736,7 +736,7 @@ void mem_cgroup_page_migration(struct page *page, struct page *newpage) 


	mz = page_cgroup_zoneinfo(pc);

	spin_lock_irqsave(&mz->lru_lock, flags);

	__mem_cgroup_remove_list(pc);

	__mem_cgroup_remove_list(mz, pc);

	spin_unlock_irqrestore(&mz->lru_lock, flags);



	page_assign_page_cgroup(page, NULL);
@@ -748,7 +748,7 @@ void mem_cgroup_page_migration(struct page *page, struct page *newpage) 


	mz = page_cgroup_zoneinfo(pc);

	spin_lock_irqsave(&mz->lru_lock, flags);

	__mem_cgroup_add_list(pc);

	__mem_cgroup_add_list(mz, pc);

	spin_unlock_irqrestore(&mz->lru_lock, flags);



	unlock_page_cgroup(newpage);