Re: [External] Re: [PATCH 2/7] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

2021-04-15 Thread Michal Hocko
On Thu 15-04-21 11:13:16, Muchun Song wrote: > On Wed, Apr 14, 2021 at 6:15 PM Michal Hocko wrote: > > > > On Wed 14-04-21 18:04:35, Muchun Song wrote: > > > On Wed, Apr 14, 2021 at 5:24 PM Michal Hocko wrote: > > > > > > > > On Tue 13-04-21 14:51:48, Muchun Song wrote: > > > > > When mm is

Re: [External] Re: [PATCH 2/7] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

2021-04-14 Thread Muchun Song
On Wed, Apr 14, 2021 at 6:15 PM Michal Hocko wrote: > > On Wed 14-04-21 18:04:35, Muchun Song wrote: > > On Wed, Apr 14, 2021 at 5:24 PM Michal Hocko wrote: > > > > > > On Tue 13-04-21 14:51:48, Muchun Song wrote: > > > > When mm is NULL, we do not need to hold rcu lock and call css_tryget for >

Re: [External] Re: [PATCH 2/7] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

2021-04-14 Thread Michal Hocko
On Wed 14-04-21 18:04:35, Muchun Song wrote: > On Wed, Apr 14, 2021 at 5:24 PM Michal Hocko wrote: > > > > On Tue 13-04-21 14:51:48, Muchun Song wrote: > > > When mm is NULL, we do not need to hold rcu lock and call css_tryget for > > > the root memcg. And we also do not need to check !mm in

Re: [External] Re: [PATCH 2/7] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

2021-04-14 Thread Muchun Song
On Wed, Apr 14, 2021 at 5:24 PM Michal Hocko wrote: > > On Tue 13-04-21 14:51:48, Muchun Song wrote: > > When mm is NULL, we do not need to hold rcu lock and call css_tryget for > > the root memcg. And we also do not need to check !mm in every loop of > > while. So bail out early when !mm. > >

Re: [PATCH 2/7] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

2021-04-14 Thread Michal Hocko
On Tue 13-04-21 14:51:48, Muchun Song wrote: > When mm is NULL, we do not need to hold rcu lock and call css_tryget for > the root memcg. And we also do not need to check !mm in every loop of > while. So bail out early when !mm. mem_cgroup_charge and other callers unconditionally drop the

Re: [PATCH 2/7] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

2021-04-13 Thread Roman Gushchin
On Tue, Apr 13, 2021 at 02:51:48PM +0800, Muchun Song wrote: > When mm is NULL, we do not need to hold rcu lock and call css_tryget for > the root memcg. And we also do not need to check !mm in every loop of > while. So bail out early when !mm. > > Signed-off-by: Muchun Song > Acked-by: Johannes

[PATCH 2/7] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

2021-04-13 Thread Muchun Song
When mm is NULL, we do not need to hold rcu lock and call css_tryget for the root memcg. And we also do not need to check !mm in every loop of while. So bail out early when !mm. Signed-off-by: Muchun Song Acked-by: Johannes Weiner Reviewed-by: Shakeel Butt --- mm/memcontrol.c | 21