On Thu, Sep 05, 2024 at 04:51:18PM +0200, Antonino Maniscalco wrote: > This series implements preemption for A7XX targets, which allows the GPU to > switch to an higher priority ring when work is pushed to it, reducing latency > for high priority submissions. > > This series enables L1 preemption with skip_save_restore which requires > the following userspace patches to function: > > https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30544 > > A flag is added to `msm_submitqueue_create` to only allow submissions > from compatible userspace to be preempted, therefore maintaining > compatibility. > > Preemption is currently only enabled by default on A750, it can be > enabled on other targets through the `enable_preemption` module > parameter. This is because more testing is required on other targets. > > For testing on other HW it is sufficient to set that parameter to a > value of 1, then using the branch of mesa linked above, `TU_DEBUG=hiprio` > allows to run any application as high priority therefore preempting > submissions from other applications. > > The `msm_gpu_preemption_trigger` and `msm_gpu_preemption_irq` traces > added in this series can be used to observe preemption's behavior as > well as measuring preemption latency. > > Some commits from this series are based on a previous series to enable > preemption on A6XX targets: > > https://lkml.kernel.org/1520489185-21828-1-git-send-email-smasetty@xxxxxxxxxxxxxx > > Signed-off-by: Antonino Maniscalco <antomani103@xxxxxxxxx> Antonino, can you please test this once with per-process pt disabled to ensure that is not broken? It is handy sometimes while debugging. We just need to remove "adreno-smmu" compatible string from gpu smmu node in DT. -Akhil. > --- > Changes in v3: > - Added documentation about preemption > - Use quirks to determine which target supports preemption > - Add a module parameter to force disabling or enabling preemption > - Clear postamble when profiling > - Define A6XX_CP_CONTEXT_SWITCH_CNTL_LEVEL fields in a6xx.xml > - Make preemption records MAP_PRIV > - Removed user ctx record (NON_PRIV) and patch 2/9 as it's not needed > anymore > - Link to v2: https://lore.kernel.org/r/20240830-preemption-a750-t-v2-0-86aeead2cd80@xxxxxxxxx > > Changes in v2: > - Added preept_record_size for X185 in PATCH 3/7 > - Added patches to reset perf counters > - Dropped unused defines > - Dropped unused variable (fixes warning) > - Only enable preemption on a750 > - Reject MSM_SUBMITQUEUE_ALLOW_PREEMPT for unsupported targets > - Added Akhil's Reviewed-By tags to patches 1/9,2/9,3/9 > - Added Neil's Tested-By tags > - Added explanation for UAPI changes in commit message > - Link to v1: https://lore.kernel.org/r/20240815-preemption-a750-t-v1-0-7bda26c34037@xxxxxxxxx > > --- > Antonino Maniscalco (10): > drm/msm: Fix bv_fence being used as bv_rptr > drm/msm: Add a `preempt_record_size` field > drm/msm: Add CONTEXT_SWITCH_CNTL bitfields > drm/msm/A6xx: Implement preemption for A7XX targets > drm/msm/A6xx: Sync relevant adreno_pm4.xml changes > drm/msm/A6xx: Use posamble to reset counters on preemption > drm/msm/A6xx: Add traces for preemption > drm/msm/A6XX: Add a flag to allow preemption to submitqueue_create > drm/msm/A6xx: Enable preemption for A750 > Documentation: document adreno preemption > > Documentation/gpu/msm-preemption.rst | 98 +++++ > drivers/gpu/drm/msm/Makefile | 1 + > drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 7 +- > drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 331 +++++++++++++++- > drivers/gpu/drm/msm/adreno/a6xx_gpu.h | 166 ++++++++ > drivers/gpu/drm/msm/adreno/a6xx_preempt.c | 430 +++++++++++++++++++++ > drivers/gpu/drm/msm/adreno/adreno_gpu.h | 9 +- > drivers/gpu/drm/msm/msm_drv.c | 4 + > drivers/gpu/drm/msm/msm_gpu_trace.h | 28 ++ > drivers/gpu/drm/msm/msm_ringbuffer.h | 8 + > drivers/gpu/drm/msm/msm_submitqueue.c | 3 + > drivers/gpu/drm/msm/registers/adreno/a6xx.xml | 7 +- > .../gpu/drm/msm/registers/adreno/adreno_pm4.xml | 39 +- > include/uapi/drm/msm_drm.h | 5 +- > 14 files changed, 1094 insertions(+), 42 deletions(-) > --- > base-commit: 7c626ce4bae1ac14f60076d00eafe71af30450ba > change-id: 20240815-preemption-a750-t-fcee9a844b39 > > Best regards, > -- > Antonino Maniscalco <antomani103@xxxxxxxxx> >
