The assembled developers agreed at the X.Org Developers Conference 2025 that the hack added for amdgpu in drm_sched_fini() shall be removed. It shouldn't be needed by amdgpu anymore.
As it's unclear whether all drivers really follow the life time rule of entities having to be torn down before their scheduler, it is reasonable to warn for a while before removing the hack. Add a warning in drm_sched_fini() that fires if an entity is still active. Signed-off-by: Philipp Stanner <[email protected]> --- Changes in v3: - Add a READ_ONCE() + comment to make the warning slightly less horrible. Changes in v2: - Fix broken brackets. --- drivers/gpu/drm/scheduler/sched_main.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 46119aacb809..31039b08c7b9 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -1419,7 +1419,7 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched) struct drm_sched_rq *rq = sched->sched_rq[i]; spin_lock(&rq->lock); - list_for_each_entry(s_entity, &rq->entities, list) + list_for_each_entry(s_entity, &rq->entities, list) { /* * Prevents reinsertion and marks job_queue as idle, * it will be removed from the rq in drm_sched_entity_fini() @@ -1440,8 +1440,15 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched) * For now, this remains a potential race in all * drivers that keep entities alive for longer than * the scheduler. + * + * The READ_ONCE() is there to make the lockless read + * (warning about the lockless write below) slightly + * less broken... */ + if (!READ_ONCE(s_entity->stopped)) + dev_warn(sched->dev, "Tearing down scheduler with active entities!\n"); s_entity->stopped = true; + } spin_unlock(&rq->lock); kfree(sched->sched_rq[i]); } -- 2.49.0
