Commit bd0d24bf authored by Daisuke Nishimura's avatar Daisuke Nishimura Committed by Linus Torvalds
Browse files

memcg: remove redundant code 



- try_get_mem_cgroup_from_mm() calls rcu_read_lock/unlock by itself, so we
  don't have to call them in task_in_mem_cgroup().
- *mz is not used in __mem_cgroup_uncharge_common().
- we don't have to call lookup_page_cgroup() in mem_cgroup_end_migration()
  after we've cleared PCG_MIGRATION of @oldpage.
- remove empty comment.
- remove redundant empty line in mem_cgroup_cache_charge().

Signed-off-by: default avatarDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2bd9bb20

mm/memcontrol.c

+0 −10
Original line number Diff line number Diff line
@@ -840,9 +840,7 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) 
	struct mem_cgroup *curr = NULL;



	task_lock(task);

	rcu_read_lock();

	curr = try_get_mem_cgroup_from_mm(task->mm);

	rcu_read_unlock();

	task_unlock(task);

	if (!curr)

		return 0;
@@ -2092,7 +2090,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, 
	if (!(gfp_mask & __GFP_WAIT)) {

		struct page_cgroup *pc;





		pc = lookup_page_cgroup(page);

		if (!pc)

			return 0;
@@ -2286,7 +2283,6 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) 
{

	struct page_cgroup *pc;

	struct mem_cgroup *mem = NULL;

	struct mem_cgroup_per_zone *mz;



	if (mem_cgroup_disabled())

		return NULL;
@@ -2340,7 +2336,6 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) 
	 * special functions.

	 */



	mz = page_cgroup_zoneinfo(pc);

	unlock_page_cgroup(pc);



	memcg_check_events(mem, page);
@@ -2652,11 +2647,8 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem, 
	ClearPageCgroupMigration(pc);

	unlock_page_cgroup(pc);



	if (unused != oldpage)

		pc = lookup_page_cgroup(unused);

	__mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);



	pc = lookup_page_cgroup(used);

	/*

	 * If a page is a file cache, radix-tree replacement is very atomic

	 * and we can skip this check. When it was an Anon page, its mapcount
@@ -3800,8 +3792,6 @@ static int mem_cgroup_oom_control_read(struct cgroup *cgrp, 
	return 0;

}



/*

 */

static int mem_cgroup_oom_control_write(struct cgroup *cgrp,

	struct cftype *cft, u64 val)

{

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