Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-05 Thread Kirill Tkhai
On 04.04.2018 19:25, Waiman Long wrote: > On 04/04/2018 11:55 AM, Kirill Tkhai wrote: >> On 04.04.2018 18:51, Kirill Tkhai wrote: >>> On 04.04.2018 18:35, Peter Zijlstra wrote: On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > The following situation leads to deadlock: >

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-05 Thread Kirill Tkhai
On 04.04.2018 19:25, Waiman Long wrote: > On 04/04/2018 11:55 AM, Kirill Tkhai wrote: >> On 04.04.2018 18:51, Kirill Tkhai wrote: >>> On 04.04.2018 18:35, Peter Zijlstra wrote: On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > The following situation leads to deadlock: >

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-05 Thread Kirill Tkhai
On 04.04.2018 19:18, Peter Zijlstra wrote: > On Wed, Apr 04, 2018 at 06:51:08PM +0300, Kirill Tkhai wrote: >> On 04.04.2018 18:35, Peter Zijlstra wrote: >>> On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: The following situation leads to deadlock: [task 1]

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-05 Thread Kirill Tkhai
On 04.04.2018 19:18, Peter Zijlstra wrote: > On Wed, Apr 04, 2018 at 06:51:08PM +0300, Kirill Tkhai wrote: >> On 04.04.2018 18:35, Peter Zijlstra wrote: >>> On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: The following situation leads to deadlock: [task 1]

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Waiman Long
On 04/04/2018 11:55 AM, Kirill Tkhai wrote: > On 04.04.2018 18:51, Kirill Tkhai wrote: >> On 04.04.2018 18:35, Peter Zijlstra wrote: >>> On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: The following situation leads to deadlock: [task 1] [task

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Waiman Long
On 04/04/2018 11:55 AM, Kirill Tkhai wrote: > On 04.04.2018 18:51, Kirill Tkhai wrote: >> On 04.04.2018 18:35, Peter Zijlstra wrote: >>> On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: The following situation leads to deadlock: [task 1] [task

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Peter Zijlstra
On Wed, Apr 04, 2018 at 06:51:08PM +0300, Kirill Tkhai wrote: > On 04.04.2018 18:35, Peter Zijlstra wrote: > > On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > >> The following situation leads to deadlock: > >> > >> [task 1] [task 2]

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Peter Zijlstra
On Wed, Apr 04, 2018 at 06:51:08PM +0300, Kirill Tkhai wrote: > On 04.04.2018 18:35, Peter Zijlstra wrote: > > On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > >> The following situation leads to deadlock: > >> > >> [task 1] [task 2]

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Kirill Tkhai
On 04.04.2018 18:51, Kirill Tkhai wrote: > On 04.04.2018 18:35, Peter Zijlstra wrote: >> On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: >>> The following situation leads to deadlock: >>> >>> [task 1] [task 2] [task 3] >>>

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Kirill Tkhai
On 04.04.2018 18:51, Kirill Tkhai wrote: > On 04.04.2018 18:35, Peter Zijlstra wrote: >> On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: >>> The following situation leads to deadlock: >>> >>> [task 1] [task 2] [task 3] >>>

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Kirill Tkhai
On 04.04.2018 18:35, Peter Zijlstra wrote: > On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: >> The following situation leads to deadlock: >> >> [task 1] [task 2] [task 3] >> kill_fasync() mm_update_next_owner()

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Kirill Tkhai
On 04.04.2018 18:35, Peter Zijlstra wrote: > On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: >> The following situation leads to deadlock: >> >> [task 1] [task 2] [task 3] >> kill_fasync() mm_update_next_owner()

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Greg KH
On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > The following situation leads to deadlock: > > [task 1] [task 2] [task 3] > kill_fasync() mm_update_next_owner() > copy_process() >

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Greg KH
On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > The following situation leads to deadlock: > > [task 1] [task 2] [task 3] > kill_fasync() mm_update_next_owner() > copy_process() >

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Peter Zijlstra
On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > The following situation leads to deadlock: > > [task 1] [task 2] [task 3] > kill_fasync() mm_update_next_owner() > copy_process() >

Re: [PATCH] locking/qrwlock: Give priority to readers with irqs disabled to prevent deadlock

2018-04-04 Thread Peter Zijlstra
On Wed, Apr 04, 2018 at 06:24:39PM +0300, Kirill Tkhai wrote: > The following situation leads to deadlock: > > [task 1] [task 2] [task 3] > kill_fasync() mm_update_next_owner() > copy_process() >