Re: [PATCH v7 00/15] dma-fence: Deadline awareness

[Rob Clark]

On Tue, Feb 28, 2023 at 4:43 AM Bagas Sanjaya <bagasdotme@xxxxxxxxx> wrote:
>
> On Mon, Feb 27, 2023 at 11:35:06AM -0800, Rob Clark wrote:
> > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> >
> > This series adds a deadline hint to fences, so realtime deadlines
> > such as vblank can be communicated to the fence signaller for power/
> > frequency management decisions.
> >
> > This is partially inspired by a trick i915 does, but implemented
> > via dma-fence for a couple of reasons:
> >
> > 1) To continue to be able to use the atomic helpers
> > 2) To support cases where display and gpu are different drivers
> >
> > This iteration adds a dma-fence ioctl to set a deadline (both to
> > support igt-tests, and compositors which delay decisions about which
> > client buffer to display), and a sw_sync ioctl to read back the
> > deadline.  IGT tests utilizing these can be found at:
> >
> >   https://gitlab.freedesktop.org/robclark/igt-gpu-tools/-/commits/fence-deadline
> >
> >
> > v1: https://patchwork.freedesktop.org/series/93035/
> > v2: Move filtering out of later deadlines to fence implementation
> >     to avoid increasing the size of dma_fence
> > v3: Add support in fence-array and fence-chain; Add some uabi to
> >     support igt tests and userspace compositors.
> > v4: Rebase, address various comments, and add syncobj deadline
> >     support, and sync_file EPOLLPRI based on experience with perf/
> >     freq issues with clvk compute workloads on i915 (anv)
> > v5: Clarify that this is a hint as opposed to a more hard deadline
> >     guarantee, switch to using u64 ns values in UABI (still absolute
> >     CLOCK_MONOTONIC values), drop syncobj related cap and driver
> >     feature flag in favor of allowing count_handles==0 for probing
> >     kernel support.
> > v6: Re-work vblank helper to calculate time of _start_ of vblank,
> >     and work correctly if the last vblank event was more than a
> >     frame ago.  Add (mostly unrelated) drm/msm patch which also
> >     uses the vblank helper.  Use dma_fence_chain_contained().  More
> >     verbose syncobj UABI comments.  Drop DMA_FENCE_FLAG_HAS_DEADLINE_BIT.
> > v7: Fix kbuild complaints about vblank helper.  Add more docs.
> >
>
> I want to apply this series for testing, but it can't be applied cleanly
> on current drm-misc tree. On what tree (and commit) is this series based
> on?

You can find my branch here:

https://gitlab.freedesktop.org/robclark/msm/-/commits/dma-fence/deadline

BR,
-R