On Thu, May 27, 2021 at 09:41:46AM +0100, Tvrtko Ursulin wrote: > > On 26/05/2021 19:15, Matthew Brost wrote: > > On Wed, May 26, 2021 at 10:25:13AM +0100, Tvrtko Ursulin wrote: > > > > > > On 25/05/2021 18:01, Matthew Brost wrote: > > > > On Tue, May 25, 2021 at 10:52:01AM +0100, Tvrtko Ursulin wrote: > > > > > > > > > > On 06/05/2021 20:14, Matthew Brost wrote: > > > > > > Disable semaphores when using GuC scheduling as semaphores are broken in > > > > > > the current GuC firmware. > > > > > > > > > > What is "current"? Given that the patch itself is like year and a half old. > > > > > > > > > > > > > Stale comment. Semaphore work with the firmware we just haven't enabled > > > > them in the i915 with GuC submission as this an optimization and not > > > > required for functionality. > > > > > > How will the updated commit message look in terms of remaining reasons why > > > semaphores won't/can't be enabled? > > > > > > > Semaphores are an optimization and not required for basic GuC submission > > to work properly. Disable until we have time to do the implementation to > > enable semaphores and tune them for performance. > > > > > They were a nice performance win on some media workloads although granted a > > > lot of tweaking was required to find a good balance on when to use them and > > > when not to. > > > > > > > The same tweaking would have to be done for with GuC submission. Let's > > get basic submission then tweak for performance. > > I don't have fundamental complaints as longs as commit message is improved > and it is understood the absence of semaphores is extremely likely to > regress transcode performance tests. Latter probably doesn't matter (for > some definition of it) unless either there will be a platform where both GuC > and execlists can be supported, or there will be two separate platforms > similar in hw performance in theory, both relevant to transcode customers, > one using execlists and one using GuC. > Sounds good. Already have this commit message updated in my branch and will be included in the next post. Matt > Regards, > > Tvrtko > >
