Commit 82abf337 authored Dec 07, 2018 by Eric Anholt Committed by Alex Deucher Feb 08, 2019

drm/sched: Always trace the dependencies we wait on, to fix a race.



The entity->dependency can go away completely once we've called
drm_sched_entity_add_dependency_cb() (if the cb is called before we
get around to tracing).  The tracepoint is more useful if we trace
every dependency instead of just ones that get callbacks installed,
anyway, so just do that.

Fixes any easy-to-produce OOPS when tracing the scheduler on V3D with
"perf record -a -e gpu_scheduler:.\* glxgears" and DEBUG_SLAB enabled.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

parent 78eb1ca4

drivers/gpu/drm/scheduler/sched_entity.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -440,14 +440,11 @@ struct drm_sched_job drm_sched_entity_pop_job(struct drm_sched_entity entity)

		while ((entity->dependency =
		sched->ops->dependency(sched_job, entity))) {
		trace_drm_sched_job_wait_dep(sched_job, entity->dependency);

		if (drm_sched_entity_add_dependency_cb(entity)) {

		trace_drm_sched_job_wait_dep(sched_job,
		entity->dependency);
		if (drm_sched_entity_add_dependency_cb(entity))
		return NULL;
		}
		}

		/* skip jobs from entity that marked guilty */
		if (entity->guilty && atomic_read(entity->guilty))

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