Commit 271dd6b1 authored by Muchun Song's avatar Muchun Song Committed by Linus Torvalds
Browse files

mm: memcontrol: move obj_cgroup_uncharge_pages() out of css_set_lock 

The css_set_lock is used to guard the list of inherited objcgs.  So there
is no need to uncharge kernel memory under css_set_lock.  Just move it out
of the lock.

Link: https://lkml.kernel.org/r/20210417043538.9793-8-songmuchun@bytedance.com


Signed-off-by: default avatarMuchun Song <songmuchun@bytedance.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Acked-by: default avatarRoman Gushchin <guro@fb.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9838354e

mm/memcontrol.c

+2 −1
Original line number Diff line number Diff line
@@ -289,9 +289,10 @@ static void obj_cgroup_release(struct percpu_ref *ref) 
	WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1));

	nr_pages = nr_bytes >> PAGE_SHIFT;



	spin_lock_irqsave(&css_set_lock, flags);

	if (nr_pages)

		obj_cgroup_uncharge_pages(objcg, nr_pages);



	spin_lock_irqsave(&css_set_lock, flags);

	list_del(&objcg->list);

	spin_unlock_irqrestore(&css_set_lock, flags);