Re: [Nouveau] [PATCH 09/17] drm/radeon: use common fence implementation for fences

Christian König
2014-07-23T09:48:09Z

Am 23.07.2014 11:44, schrieb Daniel Vetter:
> On Wed, Jul 23, 2014 at 11:39 AM, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>> The scheduler needs to keep track of a lot of fences, so I think we'll
>> have to register callbacks, not a simple wait function. We must keep
>> track of all the non-i915 fences for all oustanding batches. Also, the
>> scheduler doesn't eliminate the hw queue, only keep it much slower so
>> that we can sneak in higher priority things.
>>
>> Really, scheduler or not is orthogonal.
> Also see my other comment about interactions between wait_fence and
> the i915 reset logic. We can't actually use it from within the
> scheduler code since that would deadlock.

Yeah, I see. You would need some way to abort the waiting on other
devices fences in case of a lockup.

What about an userspace thread to offload waiting and command submission to?

Just playing with ideas right now,
Christian.

> -Daniel