Re: [PATCH] mm : Avoid candidate task is equal to current task

2014-04-18 Thread Oleg Nesterov
On 04/17, Peter Chiang wrote: > > It is a speculation where the panic was. > > [38261.652100] Call trace: > [38261.654616] [] mm_update_next_owner+0x190/0x238 > [38261.660766] [] do_exit+0x204/0x924 > [38261.665790] [] do_group_exit+0x40/0xcc > [38261.671169] [] get_signal_to_deliver+0x218/0x57c >

RE: [PATCH] mm : Avoid candidate task is equal to current task

2014-04-16 Thread Peter Chiang
...@kernel.org; pa...@ucw.cz; ebied...@xmission.com; guilla...@morinfr.org; linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm : Avoid candidate task is equal to current task On 04/16, Peter Chiang wrote: > > mm_update_next_owner() call from exit_mm() , and exit_mm() change > tsk->mm

Re: [PATCH] mm : Avoid candidate task is equal to current task

2014-04-16 Thread Oleg Nesterov
On 04/16, Peter Chiang wrote: > > mm_update_next_owner() call from exit_mm() , and exit_mm() change tsk->mm > to NULL If p==c , It seems to be impossible that mm == c->mm (tsk->mm) . > Because mm is non-NULL and c->mm is NULL . Confused, please see below. > Fix kernel panic when finding a new

RE: [PATCH] mm : Avoid candidate task is equal to current task

2014-04-16 Thread Peter Chiang
rg; pa...@ucw.cz; ebied...@xmission.com; guilla...@morinfr.org Cc: linux-kernel@vger.kernel.org Subject: RE: [PATCH] mm : Avoid candidate task is equal to current task mm_update_next_owner() call from exit_mm() , and exit_mm() change tsk->mm to NULL If p==c , It seems to be impossible that mm

RE: [PATCH] mm : Avoid candidate task is equal to current task

2014-04-16 Thread Peter Chiang
mm_update_next_owner() call from exit_mm() , and exit_mm() change tsk->mm to NULL If p==c , It seems to be impossible that mm == c->mm (tsk->mm) . Because mm is non-NULL and c->mm is NULL . -Original Message- From: Peter Chiang [mailto:pchi...@nvidia.com] Sent: Wednesday, April 16