Messages in this thread Patch in this message | | | From | Waiman Long <> | Subject | [PATCH] mm: memcontrol: Don't css_get() on root_mem_cgroup in get_mem_cgroup_from_mm() | Date | Thu, 12 Oct 2023 12:15:04 -0400 |
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As reference counting in the root memcg is disabled, there is no need to get a reference if root memcg is to be returned.
Signed-off-by: Waiman Long <longman@redhat.com> --- mm/memcontrol.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5b009b233ab8..2b3864194042 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1060,8 +1060,10 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) rcu_read_lock(); do { memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); - if (unlikely(!memcg)) + if (unlikely(!memcg)) { memcg = root_mem_cgroup; + break; + } } while (!css_tryget(&memcg->css)); rcu_read_unlock(); return memcg; -- 2.39.3
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