Re: [PATCH v3] writeback: safer lock nesting

2018-04-10 Thread Michal Hocko
On Tue 10-04-18 13:48:37, Andrew Morton wrote: > On Tue, 10 Apr 2018 08:33:57 +0200 Michal Hocko wrote: > > > > Reported-by: Wang Long > > > Signed-off-by: Greg Thelen > > > Change-Id: Ibb773e8045852978f6207074491d262f1b3fb613 > > > > Not a stable material IMHO > > Why's that? Wang Long said

Re: [PATCH v3] writeback: safer lock nesting

2018-04-10 Thread Greg Thelen
On Tue, Apr 10, 2018 at 1:38 PM Andrew Morton wrote: > On Mon, 9 Apr 2018 17:59:08 -0700 Greg Thelen wrote: > > lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if > > the page's memcg is undergoing move accounting, which occurs when a > > process leaves its memcg for a ne

Re: [PATCH v3] writeback: safer lock nesting

2018-04-10 Thread Greg Thelen
On Tue, Apr 10, 2018 at 1:15 AM Wang Long wrote: > > lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if > > the page's memcg is undergoing move accounting, which occurs when a > > process leaves its memcg for a new one that has > > memory.move_charge_at_immigrate set. > > >

Re: [PATCH v3] writeback: safer lock nesting

2018-04-10 Thread Andrew Morton
On Tue, 10 Apr 2018 08:33:57 +0200 Michal Hocko wrote: > > Reported-by: Wang Long > > Signed-off-by: Greg Thelen > > Change-Id: Ibb773e8045852978f6207074491d262f1b3fb613 > > Not a stable material IMHO Why's that? Wang Long said he's observed the deadlock three times?

Re: [PATCH v3] writeback: safer lock nesting

2018-04-10 Thread Andrew Morton
On Mon, 9 Apr 2018 17:59:08 -0700 Greg Thelen wrote: > lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if > the page's memcg is undergoing move accounting, which occurs when a > process leaves its memcg for a new one that has > memory.move_charge_at_immigrate set. > > unlo

Re: [PATCH v3] writeback: safer lock nesting

2018-04-10 Thread Wang Long
lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if the page's memcg is undergoing move accounting, which occurs when a process leaves its memcg for a new one that has memory.move_charge_at_immigrate set. unlocked_inode_to_wb_begin,end() use spin_lock_irq/spin_unlock_irq() if

Re: [PATCH v3] writeback: safer lock nesting

2018-04-09 Thread Michal Hocko
On Mon 09-04-18 17:59:08, Greg Thelen wrote: > lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if > the page's memcg is undergoing move accounting, which occurs when a > process leaves its memcg for a new one that has > memory.move_charge_at_immigrate set. > > unlocked_inode_