[PATCH v4 0/7] Use DRM scheduler for delayed GT TLB invalidations

[Matthew Brost]

MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

      Use the DRM scheduler for delayed GT TLB invalidations, which properly
fixes the issue raised in [1]. GT TLB fences have their own dma-fence
context, so even if the invalidations are ordered, the dma-resv/DRM
scheduler cannot squash the fences. This results in O(M*N*N) complexity
in the garbage collector, where M is the number of ranges in the garbage
collector and N is the number of pending GT TLB invalidations. After
this change, the resulting complexity in O(M*C) where C is the number of
TLB invalidation contexts (i.e., number of exec queue, GTs tuples) with
an invalidation in flight.

Admittedly, it's quite a lot of code, but the series includes extensive
kernel documentation and clear code comments. It introduces a generic
dependency scheduler that can be reused in the future and is logically
much cleaner than the previous open-coded solution for delaying GT TLB
invalidations until a bind job completes.

v2:
 - Various cleanup covered in detail in change logs
 - Use a per-GT ordered workqueue as DRM scheduler workqueue
 - Remove unused ftrace points
v3:
 - Address Stuarts feedback
 - Fix kernel doc, minor cleanups
v4:
 - Rebase

Matt

[1] https://patchwork.freedesktop.org/patch/658370/?series=150188&rev=1

Matthew Brost (7):
  drm/xe: Explicitly mark migration queues with flag
  drm/xe: Add generic dependecy jobs / scheduler
  drm/xe: Create ordered workqueue for GT TLB invalidation jobs
  drm/xe: Add dependency scheduler for GT TLB invalidations to bind
    queues
  drm/xe: Add GT TLB invalidation jobs
  drm/xe: Use GT TLB invalidation jobs in PT layer
  drm/xe: Remove unused GT TLB invalidation trace points

 drivers/gpu/drm/xe/Makefile                 |   2 +
 drivers/gpu/drm/xe/xe_dep_job_types.h       |  29 +++
 drivers/gpu/drm/xe/xe_dep_scheduler.c       | 143 ++++++++++
 drivers/gpu/drm/xe/xe_dep_scheduler.h       |  21 ++
 drivers/gpu/drm/xe/xe_exec_queue.c          |  48 ++++
 drivers/gpu/drm/xe/xe_exec_queue_types.h    |  15 ++
 drivers/gpu/drm/xe/xe_gt_tlb_inval_job.c    | 274 ++++++++++++++++++++
 drivers/gpu/drm/xe/xe_gt_tlb_inval_job.h    |  34 +++
 drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c |   8 +
 drivers/gpu/drm/xe/xe_gt_types.h            |   2 +
 drivers/gpu/drm/xe/xe_migrate.c             |  42 ++-
 drivers/gpu/drm/xe/xe_migrate.h             |  13 +
 drivers/gpu/drm/xe/xe_pt.c                  | 178 +++++--------
 drivers/gpu/drm/xe/xe_trace.h               |  16 --
 14 files changed, 700 insertions(+), 125 deletions(-)
 create mode 100644 drivers/gpu/drm/xe/xe_dep_job_types.h
 create mode 100644 drivers/gpu/drm/xe/xe_dep_scheduler.c
 create mode 100644 drivers/gpu/drm/xe/xe_dep_scheduler.h
 create mode 100644 drivers/gpu/drm/xe/xe_gt_tlb_inval_job.c
 create mode 100644 drivers/gpu/drm/xe/xe_gt_tlb_inval_job.h

-- 
2.34.1