[Intel-gfx] [PATCH 1/2] drm/i915: Stop retiring requests from busy-ioctl

[Tvrtko Ursulin]

On 13/05/16 09:50, Chris Wilson wrote:
> On Fri, May 13, 2016 at 09:38:54AM +0100, Tvrtko Ursulin wrote:
>>
>> On 12/05/16 11:25, Chris Wilson wrote:
>>> In order to reduce the workload of the caller, we do not want to
>>> actually have to retire requests of others when checking the status of
>>> this object.
>>
>> Wrt the subject, and from wait ioctl as well.
>>
>> Also i915_gem_object_sync / i915_gem_execbuffer_move_to_gpu path
>> (execbuf) looks like it could still do the upto retiring so that
>> isn't only moving the thing around?
>>
>> And in general, commit does not say who was impacted by this and how much?
>
> Nothing much until we have them all removed. Please see the other
> patches! The end result in having a completely lockless busy-ioctl is a
> major improvement to a minor path... The impact is really only measured
> by reduced contention between clients, for which the busy-ioctl is
> mostly a victim.
>
> This was just an opportunistic change to reduce the numer of
> retire__upto when thinking about the bugfix in patch 2.

I don't mind the idea, just though it needs more explaining in the
commit and updated subject.

I don't know the reset path nearly well enough to comment on 2/2.

Regards,

Tvrtko