From 271dd6b1f636a99a3a77889935296c063f5a3cbe Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Mon, 28 Jun 2021 19:38:06 -0700 Subject: [PATCH] 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: Muchun Song Reviewed-by: Shakeel Butt Acked-by: Roman Gushchin Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Xiongchun Duan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c79b692..f7a552e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -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); -- 2.7.4