[v6,00/15] dma-fence: Deadline awareness

Message

Rob Clark Feb. 24, 2023, 8:01 p.m. UTC

From: Rob Clark <[e-mail]>


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.

Rob Clark (15):
  dma-buf/dma-fence: Add deadline awareness
  dma-buf/fence-array: Add fence deadline support
  dma-buf/fence-chain: Add fence deadline support
  dma-buf/dma-resv: Add a way to set fence deadline
  dma-buf/sync_file: Add SET_DEADLINE ioctl
  dma-buf/sync_file: Support (E)POLLPRI
  dma-buf/sw_sync: Add fence deadline support
  drm/scheduler: Add fence deadline support
  drm/syncobj: Add deadline support for syncobj waits
  drm/vblank: Add helper to get next vblank time
  drm/atomic-helper: Set fence deadline for vblank
  drm/msm: Add deadline based boost support
  drm/msm: Add wait-boost support
  drm/msm/atomic: Switch to vblank_start helper
  drm/i915: Add deadline based boost support

 drivers/dma-buf/dma-fence-array.c       | 11 ++++
 drivers/dma-buf/dma-fence-chain.c       | 12 ++++
 drivers/dma-buf/dma-fence.c             | 20 +++++++
 drivers/dma-buf/dma-resv.c              | 22 ++++++++
 drivers/dma-buf/sw_sync.c               | 58 +++++++++++++++++++
 drivers/dma-buf/sync_debug.h            |  2 +
 drivers/dma-buf/sync_file.c             | 27 +++++++++
 drivers/gpu/drm/drm_atomic_helper.c     | 36 ++++++++++++
 drivers/gpu/drm/drm_syncobj.c           | 64 ++++++++++++++++-----
 drivers/gpu/drm/drm_vblank.c            | 52 ++++++++++++++---
 drivers/gpu/drm/i915/i915_request.c     | 20 +++++++
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 15 -----
 drivers/gpu/drm/msm/msm_atomic.c        |  8 ++-
 drivers/gpu/drm/msm/msm_drv.c           | 12 ++--
 drivers/gpu/drm/msm/msm_fence.c         | 74 +++++++++++++++++++++++++
 drivers/gpu/drm/msm/msm_fence.h         | 20 +++++++
 drivers/gpu/drm/msm/msm_gem.c           |  5 ++
 drivers/gpu/drm/msm/msm_kms.h           |  8 ---
 drivers/gpu/drm/scheduler/sched_fence.c | 46 +++++++++++++++
 drivers/gpu/drm/scheduler/sched_main.c  |  2 +-
 include/drm/drm_vblank.h                |  1 +
 include/drm/gpu_scheduler.h             | 17 ++++++
 include/linux/dma-fence.h               | 19 +++++++
 include/linux/dma-resv.h                |  2 +
 include/uapi/drm/drm.h                  | 17 ++++++
 include/uapi/drm/msm_drm.h              | 14 ++++-
 include/uapi/linux/sync_file.h          | 26 +++++++++
 27 files changed, 555 insertions(+), 55 deletions(-)