Commit 8289546e authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

memcg: remove mem_cgroup_uncharge 



Nothing uses mem_cgroup_uncharge apart from mem_cgroup_uncharge_page, (a
trivial wrapper around it) and mem_cgroup_end_migration (which does the same
as mem_cgroup_uncharge_page).  And it often ends up having to lock just to let
its caller unlock.  Remove it (but leave the silly locking until a later
patch).

Moved mem_cgroup_cache_charge next to mem_cgroup_charge in memcontrol.h.

Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7e924aaf

include/linux/memcontrol.h

+7 −13
Original line number Diff line number Diff line
@@ -35,7 +35,8 @@ extern void mm_free_cgroup(struct mm_struct *mm); 
extern struct page_cgroup *page_get_page_cgroup(struct page *page);

extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm,

				gfp_t gfp_mask);

extern void mem_cgroup_uncharge(struct page_cgroup *pc);

extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,

					gfp_t gfp_mask);

extern void mem_cgroup_uncharge_page(struct page *page);

extern void mem_cgroup_move_lists(struct page *page, bool active);

extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
@@ -45,8 +46,6 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, 
					struct mem_cgroup *mem_cont,

					int active);

extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask);

extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,

					gfp_t gfp_mask);

int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);



#define mm_match_cgroup(mm, cgroup)	\
@@ -92,14 +91,16 @@ static inline struct page_cgroup *page_get_page_cgroup(struct page *page) 
	return NULL;

}



static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,

					gfp_t gfp_mask)

static inline int mem_cgroup_charge(struct page *page,

					struct mm_struct *mm, gfp_t gfp_mask)

{

	return 0;

}



static inline void mem_cgroup_uncharge(struct page_cgroup *pc)

static inline int mem_cgroup_cache_charge(struct page *page,

					struct mm_struct *mm, gfp_t gfp_mask)

{

	return 0;

}



static inline void mem_cgroup_uncharge_page(struct page *page)
@@ -110,13 +111,6 @@ static inline void mem_cgroup_move_lists(struct page *page, bool active) 
{

}



static inline int mem_cgroup_cache_charge(struct page *page,

						struct mm_struct *mm,

						gfp_t gfp_mask)

{

	return 0;

}



static inline int mm_match_cgroup(struct mm_struct *mm, struct mem_cgroup *mem)

{

	return 1;

mm/memcontrol.c

+8 −15
Original line number Diff line number Diff line
@@ -697,20 +697,22 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, 


/*

 * Uncharging is always a welcome operation, we never complain, simply

 * uncharge. This routine should be called with lock_page_cgroup held

 * uncharge.

 */

void mem_cgroup_uncharge(struct page_cgroup *pc)

void mem_cgroup_uncharge_page(struct page *page)

{

	struct page_cgroup *pc;

	struct mem_cgroup *mem;

	struct mem_cgroup_per_zone *mz;

	struct page *page;

	unsigned long flags;



	/*

	 * Check if our page_cgroup is valid

	 */

	lock_page_cgroup(page);

	pc = page_get_page_cgroup(page);

	if (!pc)

		return;

		goto unlock;



	if (atomic_dec_and_test(&pc->ref_cnt)) {

		page = pc->page;
@@ -731,12 +733,8 @@ void mem_cgroup_uncharge(struct page_cgroup *pc) 
		}

		lock_page_cgroup(page);

	}

}



void mem_cgroup_uncharge_page(struct page *page)

{

	lock_page_cgroup(page);

	mem_cgroup_uncharge(page_get_page_cgroup(page));

unlock:

	unlock_page_cgroup(page);

}
@@ -759,12 +757,7 @@ int mem_cgroup_prepare_migration(struct page *page) 


void mem_cgroup_end_migration(struct page *page)

{

	struct page_cgroup *pc;



	lock_page_cgroup(page);

	pc = page_get_page_cgroup(page);

	mem_cgroup_uncharge(pc);

	unlock_page_cgroup(page);

	mem_cgroup_uncharge_page(page);

}

/*

 * We know both *page* and *newpage* are now not-on-LRU and Pg_locked.

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