[igt-dev] [PATCH i-g-t] lib/i915: Fix gem_has_execlists to match description

Dixit, Ashutosh ashutosh.dixit at intel.com
Mon Oct 18 22:11:31 UTC 2021


On Mon, 18 Oct 2021 00:43:10 -0700, Tvrtko Ursulin wrote:
>
> >>> Don't we use ring submission on older platforms?
> >> Hmm, I wasn't aware that there was yet another submission method :/
> >>
> >> So execlist submission is only available for gen >= 8 as the code says,
> >> in
> >> case anyone knows?
> > Yes. Execlists was new feature of the hardware not all that long ago
> > (ELSP and all that). Gen8 sounds plausible.
>
> Yes Gen8+.
>
> > Of course, it all depends why the code is asking the question? Does it
> > really need to know what the submission hardware is? Or is it actually
> > asking about the scheduling algorithm (as is the case for
> > gem_exec_fair). Or something else entirely? The scheduler question is
> > going to change again when we move to using the DRM scheduler instead of
> > our own private one in the execlist code. Currently though, I would
> > assume we use the execlist scheduler for ring submission but certainly
> > not for GuC submission (because the scheduler is in the hardware).
>
> Nope, no scheduling with ringbuffer backend.
>
> There is I915_PARAM_HAS_SCHEDULER and respective IGT helpers to query what
> kind of scheduling is supported on the device in question.
>
> It will be on a test per test basis why it is asking the question and what
> would be the appropriate test.

This patch is abandoned in favor of:

https://patchwork.freedesktop.org/series/95906/

Would it be possible to get a review on that? Thanks.


More information about the igt-dev mailing list