From: Philipp Stanner Date: Fri, 7 Nov 2025 13:57:00 +0000 (+0100) Subject: drm/todo: Add section with task for GPU scheduler X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9d56cbaf12037e8ce7ead9f8f8f9000e4784f2eb;p=thirdparty%2Fkernel%2Flinux.git drm/todo: Add section with task for GPU scheduler The GPU scheduler has a great many problems and deserves its own TODO section. Add a section and a first task describing the problem of drm_sched_resubmit_jobs() being deprecated without a successor. Acked-by: Dave Airlie Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251107135701.244659-3-phasta@kernel.org --- diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 9013ced318cb9..572a5611dd0ca 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -878,6 +878,37 @@ Contact: Christian König Level: Starter +DRM GPU Scheduler +================= + +Provide a universal successor for drm_sched_resubmit_jobs() +----------------------------------------------------------- + +drm_sched_resubmit_jobs() is deprecated. Main reason being that it leads to +reinitializing dma_fences. See that function's docu for details. The better +approach for valid resubmissions by amdgpu and Xe is (apparently) to figure out +which job (and, through association: which entity) caused the hang. Then, the +job's buffer data, together with all other jobs' buffer data currently in the +same hardware ring, must be invalidated. This can for example be done by +overwriting it. amdgpu currently determines which jobs are in the ring and need +to be overwritten by keeping copies of the job. Xe obtains that information by +directly accessing drm_sched's pending_list. + +Tasks: + +1. implement scheduler functionality through which the driver can obtain the + information which *broken* jobs are currently in the hardware ring. +2. Such infrastructure would then typically be used in + drm_sched_backend_ops.timedout_job(). Document that. +3. Port a driver as first user. +4. Document the new alternative in the docu of deprecated + drm_sched_resubmit_jobs(). + +Contact: Christian König + Philipp Stanner + +Level: Advanced + Outside DRM ===========