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charset=us-ascii Content-Disposition: inline In-Reply-To: <20231012161504.3445042-1-longman@redhat.com> X-Rspamd-Queue-Id: 4367C4001F X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 8s77fgq51ctnthpaefy997x5yemk6yfh X-HE-Tag: 1697206643-404506 X-HE-Meta: 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 qMkw2y9S kaFo6wYAAeDbM9Ny+Zs1V4gPpbo6zUjM4H3Sa0+sBoMXOx0PoYJiqOxKxSsM9giNMITj2FSB/1qLt8qafCxpmqx2dCcxEWqtCIzLTu1KxBeLEwRdELtX5X2IV5i3xP8EOv0bvGLZ/i+PGTO+QSweXvkjNwwgSXjihADT6BTBb+GDFDzck8OtQHenZ28NdMQaeEXPZ6WQUt9CPCUcERS1kniY+NA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu 12-10-23 12:15:04, Waiman Long wrote: > As reference counting in the root memcg is disabled, there is no need > to get a reference if root memcg is to be returned. Does this give any measurable wins? > Signed-off-by: Waiman Long > --- > 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 -- Michal Hocko SUSE Labs