[Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine in set_wedged

2017-10-11 Thread Daniel Vetter
stop_machine is not really a locking primitive we should use, except when the hw folks tell us the hw is broken and that's the only way to work around it. This patch tries to address the locking abuse of stop_machine() from commit 20e4933c478a1ca694b38fa4ac44d99e659941f5 Author: Chris Wilson

[Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine in set_wedged

2017-10-10 Thread Daniel Vetter
stop_machine is not really a locking primitive we should use, except when the hw folks tell us the hw is broken and that's the only way to work around it. This patch tries to address the locking abuse of stop_machine() from commit 20e4933c478a1ca694b38fa4ac44d99e659941f5 Author: Chris Wilson

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-06 Thread Thomas Gleixner
On Fri, 6 Oct 2017, Daniel Vetter wrote: > On Fri, Oct 6, 2017 at 10:42 AM, Chris Wilson > wrote: > >> > > This patch tries to address the locking snafu from > >> > > >> > There's a locking snafu in the code? The lock problem exists definitely. We did not introduce new

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-06 Thread Daniel Vetter
On Fri, Oct 6, 2017 at 10:42 AM, Chris Wilson wrote: > Quoting Daniel Vetter (2017-10-05 17:12:35) >> On Thu, Oct 05, 2017 at 03:30:12PM +0100, Chris Wilson wrote: >> > Quoting Daniel Vetter (2017-10-05 15:09:48) >> > > stop_machine is not really a locking primitive we

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-06 Thread Daniel Vetter
On Fri, Oct 6, 2017 at 10:30 AM, Tvrtko Ursulin wrote: > > On 05/10/2017 17:24, Daniel Vetter wrote: >> >> On Thu, Oct 05, 2017 at 03:55:19PM +0100, Tvrtko Ursulin wrote: >>> >>> >>> On 05/10/2017 15:09, Daniel Vetter wrote: stop_machine is not really a

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-06 Thread Chris Wilson
Quoting Daniel Vetter (2017-10-05 17:12:35) > On Thu, Oct 05, 2017 at 03:30:12PM +0100, Chris Wilson wrote: > > Quoting Daniel Vetter (2017-10-05 15:09:48) > > > stop_machine is not really a locking primitive we should use, except > > > when the hw folks tell us the hw is broken and that's the

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-06 Thread Tvrtko Ursulin
On 05/10/2017 17:24, Daniel Vetter wrote: On Thu, Oct 05, 2017 at 03:55:19PM +0100, Tvrtko Ursulin wrote: On 05/10/2017 15:09, Daniel Vetter wrote: stop_machine is not really a locking primitive we should use, except when the hw folks tell us the hw is broken and that's the only way to work

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-05 Thread Daniel Vetter
On Thu, Oct 05, 2017 at 03:55:19PM +0100, Tvrtko Ursulin wrote: > > On 05/10/2017 15:09, Daniel Vetter wrote: > > stop_machine is not really a locking primitive we should use, except > > when the hw folks tell us the hw is broken and that's the only way to > > work around it. > > > > This patch

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-05 Thread Daniel Vetter
On Thu, Oct 05, 2017 at 03:30:12PM +0100, Chris Wilson wrote: > Quoting Daniel Vetter (2017-10-05 15:09:48) > > stop_machine is not really a locking primitive we should use, except > > when the hw folks tell us the hw is broken and that's the only way to > > work around it. > > > > This patch

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-05 Thread Tvrtko Ursulin
On 05/10/2017 15:09, Daniel Vetter wrote: stop_machine is not really a locking primitive we should use, except when the hw folks tell us the hw is broken and that's the only way to work around it. This patch here is just a suggestion for how to fix it up, possible changes needed to make it

Re: [Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-05 Thread Chris Wilson
Quoting Daniel Vetter (2017-10-05 15:09:48) > stop_machine is not really a locking primitive we should use, except > when the hw folks tell us the hw is broken and that's the only way to > work around it. > > This patch here is just a suggestion for how to fix it up, possible > changes needed to

[Intel-gfx] [PATCH] drm/i915: Use rcu instead of stop_machine

2017-10-05 Thread Daniel Vetter
stop_machine is not really a locking primitive we should use, except when the hw folks tell us the hw is broken and that's the only way to work around it. This patch here is just a suggestion for how to fix it up, possible changes needed to make it actually work: - Set the nop_submit_request