[Intel-gfx] Reconfigurable OA queries

[Chris Wilson]

Quoting Lionel Landwerlin (2019-10-09 00:14:41)
> On 09/10/2019 00:40, Chris Wilson wrote:
> > This is Lionel's work to enable OA for Vulkan, greatly bastardised on
> > top of the struct_mutex removal. It claims to be doing the right
> > thing...
> > -Chris
> >
> >
> Thanks a lot of picking this up.
> 
> I'm aware of an issue with patch 9 as I can see requests with perf 
> queries being preempted. Looking into that, but not quite there yet.

Outside of the masking issue where a later request on the same context
will mask the nopreempt request, if that nopreempt flag is set on the
last submitted request to ELSP[0], we will not allow that context to be
preempted before we consider the request to be completed.

> I think there is a dependency issue with patch 8. We also use 
> cliprects_ptr for fences.

Hmm, I was expecting the flag validation to be in the first patch to add
extension parsing, but we are missing the test if both flags are set,
reject the execbuf.

> If we start reusing it for extended parameters, we need to make fences 
> the first extended param.

Why?
-Chris