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Commit e993d905 authored by Vladimir Davydov's avatar Vladimir Davydov Committed by Linus Torvalds
Browse files

memcg: zap try_get_mem_cgroup_from_page 



It is only used in mem_cgroup_try_charge, so fold it in and zap it.

Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
Reviewed-by: default avatarAndres Lagar-Cavilla <andreslc@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 94a59fb3

include/linux/memcontrol.h

+1 −8
Original line number Diff line number Diff line
@@ -305,11 +305,9 @@ struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *); 
struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);



bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);



struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);

struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);



struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);



static inline

struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css){

	return css ? container_of(css, struct mem_cgroup, css) : NULL;
@@ -556,11 +554,6 @@ static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page, 
	return &zone->lruvec;

}



static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)

{

	return NULL;

}



static inline bool mm_match_cgroup(struct mm_struct *mm,

		struct mem_cgroup *memcg)

{

mm/memcontrol.c

+12 −36
Original line number Diff line number Diff line
@@ -2099,40 +2099,6 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) 
	css_put_many(&memcg->css, nr_pages);

}



/*

 * try_get_mem_cgroup_from_page - look up page's memcg association

 * @page: the page

 *

 * Look up, get a css reference, and return the memcg that owns @page.

 *

 * The page must be locked to prevent racing with swap-in and page

 * cache charges.  If coming from an unlocked page table, the caller

 * must ensure the page is on the LRU or this can race with charging.

 */

struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)

{

	struct mem_cgroup *memcg;

	unsigned short id;

	swp_entry_t ent;



	VM_BUG_ON_PAGE(!PageLocked(page), page);



	memcg = page->mem_cgroup;

	if (memcg) {

		if (!css_tryget_online(&memcg->css))

			memcg = NULL;

	} else if (PageSwapCache(page)) {

		ent.val = page_private(page);

		id = lookup_swap_cgroup_id(ent);

		rcu_read_lock();

		memcg = mem_cgroup_from_id(id);

		if (memcg && !css_tryget_online(&memcg->css))

			memcg = NULL;

		rcu_read_unlock();

	}

	return memcg;

}



static void lock_page_lru(struct page *page, int *isolated)

{

	struct zone *zone = page_zone(page);
@@ -5329,8 +5295,20 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, 
		 * the page lock, which serializes swap cache removal, which

		 * in turn serializes uncharging.

		 */

		VM_BUG_ON_PAGE(!PageLocked(page), page);

		if (page->mem_cgroup)

			goto out;



		if (do_swap_account) {

			swp_entry_t ent = { .val = page_private(page), };

			unsigned short id = lookup_swap_cgroup_id(ent);



			rcu_read_lock();

			memcg = mem_cgroup_from_id(id);

			if (memcg && !css_tryget_online(&memcg->css))

				memcg = NULL;

			rcu_read_unlock();

		}

	}



	if (PageTransHuge(page)) {
@@ -5338,8 +5316,6 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, 
		VM_BUG_ON_PAGE(!PageTransHuge(page), page);

	}



	if (do_swap_account && PageSwapCache(page))

		memcg = try_get_mem_cgroup_from_page(page);

	if (!memcg)

		memcg = get_mem_cgroup_from_mm(mm);