Re: [PATCH mmotm] mm: vmscan: fix shrinker_rwsem in free_shrinker_info()

2021-03-31 Thread Yang Shi
On Wed, Mar 31, 2021 at 2:13 PM Hugh Dickins wrote: > > On Wed, 31 Mar 2021, Yang Shi wrote: > > On Wed, Mar 31, 2021 at 6:54 AM Shakeel Butt wrote: > > > On Tue, Mar 30, 2021 at 4:44 PM Hugh Dickins wrote: > > > > > > > > Lockdep warns mm/vmscan.c: suspicious rcu_dereference_protected() usage!

Re: [PATCH mmotm] mm: vmscan: fix shrinker_rwsem in free_shrinker_info()

2021-03-31 Thread Hugh Dickins
On Wed, 31 Mar 2021, Yang Shi wrote: > On Wed, Mar 31, 2021 at 6:54 AM Shakeel Butt wrote: > > On Tue, Mar 30, 2021 at 4:44 PM Hugh Dickins wrote: > > > > > > Lockdep warns mm/vmscan.c: suspicious rcu_dereference_protected() usage! > > > when free_shrinker_info() is called from

Re: [PATCH mmotm] mm: vmscan: fix shrinker_rwsem in free_shrinker_info()

2021-03-31 Thread Yang Shi
On Wed, Mar 31, 2021 at 6:54 AM Shakeel Butt wrote: > > On Tue, Mar 30, 2021 at 4:44 PM Hugh Dickins wrote: > > > > Lockdep warns mm/vmscan.c: suspicious rcu_dereference_protected() usage! > > when free_shrinker_info() is called from mem_cgroup_css_free(): there it > > is called with no locking,

Re: [PATCH mmotm] mm: vmscan: fix shrinker_rwsem in free_shrinker_info()

2021-03-31 Thread Shakeel Butt
On Tue, Mar 30, 2021 at 4:44 PM Hugh Dickins wrote: > > Lockdep warns mm/vmscan.c: suspicious rcu_dereference_protected() usage! > when free_shrinker_info() is called from mem_cgroup_css_free(): there it > is called with no locking, whereas alloc_shrinker_info() calls it with > down_write of

[PATCH mmotm] mm: vmscan: fix shrinker_rwsem in free_shrinker_info()

2021-03-30 Thread Hugh Dickins
Lockdep warns mm/vmscan.c: suspicious rcu_dereference_protected() usage! when free_shrinker_info() is called from mem_cgroup_css_free(): there it is called with no locking, whereas alloc_shrinker_info() calls it with down_write of shrinker_rwsem - which seems appropriate. Rearrange that so