From bf8bbaefaa6ae0a07971ea57b3208df60e8ad0a4 Mon Sep 17 00:00:00 2001 From: Philipp Stanner Date: Thu, 10 Jul 2025 14:54:06 +0200 Subject: drm/sched: Avoid memory leaks with cancel_job() callback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since its inception, the GPU scheduler can leak memory if the driver calls drm_sched_fini() while there are still jobs in flight. The simplest way to solve this in a backwards compatible manner is by adding a new callback, drm_sched_backend_ops.cancel_job(), which instructs the driver to signal the hardware fence associated with the job. Afterwards, the scheduler can safely use the established free_job() callback for freeing the job. Implement the new backend_ops callback cancel_job(). Suggested-by: Tvrtko Ursulin Link: https://lore.kernel.org/dri-devel/20250418113211.69956-1-tvrtko.ursulin@igalia.com/ Reviewed-by: Maíra Canal Acked-by: Tvrtko Ursulin Signed-off-by: Philipp Stanner Link: https://lore.kernel.org/r/20250710125412.128476-4-phasta@kernel.org --- include/drm/gpu_scheduler.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include') diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index e62a7214e052..190844370f48 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -512,6 +512,24 @@ struct drm_sched_backend_ops { * and it's time to clean it up. */ void (*free_job)(struct drm_sched_job *sched_job); + + /** + * @cancel_job: Used by the scheduler to guarantee remaining jobs' fences + * get signaled in drm_sched_fini(). + * + * Used by the scheduler to cancel all jobs that have not been executed + * with &struct drm_sched_backend_ops.run_job by the time + * drm_sched_fini() gets invoked. + * + * Drivers need to signal the passed job's hardware fence with an + * appropriate error code (e.g., -ECANCELED) in this callback. They + * must not free the job. + * + * The scheduler will only call this callback once it stopped calling + * all other callbacks forever, with the exception of &struct + * drm_sched_backend_ops.free_job. + */ + void (*cancel_job)(struct drm_sched_job *sched_job); }; /** -- cgit v1.2.3