Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-15 Thread Daniel Vetter
On Wed, Jul 14, 2021 at 06:12:54PM -0400, Andrey Grodzovsky wrote: > > On 2021-07-13 12:45 p.m., Daniel Vetter wrote: > > On Tue, Jul 13, 2021 at 6:11 PM Andrey Grodzovsky > > wrote: > > > On 2021-07-13 5:10 a.m., Daniel Vetter wrote: > > > > On Tue, Jul 13, 2021 at 9:25 AM Christian König > > >

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-14 Thread Andrey Grodzovsky
On 2021-07-13 12:45 p.m., Daniel Vetter wrote: On Tue, Jul 13, 2021 at 6:11 PM Andrey Grodzovsky wrote: On 2021-07-13 5:10 a.m., Daniel Vetter wrote: On Tue, Jul 13, 2021 at 9:25 AM Christian König wrote: Am 13.07.21 um 08:50 schrieb Daniel Vetter: On Tue, Jul 13, 2021 at 8:35 AM Christia

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-13 Thread Daniel Vetter
On Tue, Jul 13, 2021 at 6:11 PM Andrey Grodzovsky wrote: > On 2021-07-13 5:10 a.m., Daniel Vetter wrote: > > On Tue, Jul 13, 2021 at 9:25 AM Christian König > > wrote: > >> Am 13.07.21 um 08:50 schrieb Daniel Vetter: > >>> On Tue, Jul 13, 2021 at 8:35 AM Christian König > >>> wrote: > Am 12

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-13 Thread Andrey Grodzovsky
On 2021-07-13 5:10 a.m., Daniel Vetter wrote: On Tue, Jul 13, 2021 at 9:25 AM Christian König wrote: Am 13.07.21 um 08:50 schrieb Daniel Vetter: On Tue, Jul 13, 2021 at 8:35 AM Christian König wrote: Am 12.07.21 um 19:53 schrieb Daniel Vetter: It might be good enough on x86 with just READ

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-13 Thread Christian König
Am 13.07.21 um 11:10 schrieb Daniel Vetter: On Tue, Jul 13, 2021 at 9:25 AM Christian König wrote: Am 13.07.21 um 08:50 schrieb Daniel Vetter: On Tue, Jul 13, 2021 at 8:35 AM Christian König wrote: Am 12.07.21 um 19:53 schrieb Daniel Vetter: It might be good enough on x86 with just READ_ONC

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-13 Thread Daniel Vetter
On Tue, Jul 13, 2021 at 9:25 AM Christian König wrote: > Am 13.07.21 um 08:50 schrieb Daniel Vetter: > > On Tue, Jul 13, 2021 at 8:35 AM Christian König > > wrote: > >> Am 12.07.21 um 19:53 schrieb Daniel Vetter: > >>> It might be good enough on x86 with just READ_ONCE, but the write side > >>> s

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-13 Thread Christian König
Am 13.07.21 um 08:50 schrieb Daniel Vetter: On Tue, Jul 13, 2021 at 8:35 AM Christian König wrote: Am 12.07.21 um 19:53 schrieb Daniel Vetter: It might be good enough on x86 with just READ_ONCE, but the write side should then at least be WRITE_ONCE because x86 has total store order. It's defi

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-12 Thread Daniel Vetter
On Tue, Jul 13, 2021 at 8:35 AM Christian König wrote: > > Am 12.07.21 um 19:53 schrieb Daniel Vetter: > > It might be good enough on x86 with just READ_ONCE, but the write side > > should then at least be WRITE_ONCE because x86 has total store order. > > > > It's definitely not enough on arm. > >

Re: [PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-12 Thread Christian König
Am 12.07.21 um 19:53 schrieb Daniel Vetter: It might be good enough on x86 with just READ_ONCE, but the write side should then at least be WRITE_ONCE because x86 has total store order. It's definitely not enough on arm. Fix this proplery, which means - explain the need for the barrier in both p

[PATCH v4 02/18] drm/sched: Barriers are needed for entity->last_scheduled

2021-07-12 Thread Daniel Vetter
It might be good enough on x86 with just READ_ONCE, but the write side should then at least be WRITE_ONCE because x86 has total store order. It's definitely not enough on arm. Fix this proplery, which means - explain the need for the barrier in both places - point at the other side in each commen