From 975ca62a014cb9254e07acb63ea0b81177e32c58 Mon Sep 17 00:00:00 2001 From: Philipp Stanner Date: Thu, 23 Oct 2025 14:34:30 +0200 Subject: [PATCH] drm/sched: Add warning for removing hack in drm_sched_fini() 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. Acked-by: Pierre-Eric Pelloux-Prayer Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251023123429.139848-2-phasta@kernel.org --- 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 492e8af639dbe..2463ced2427a8 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -1425,7 +1425,7 @@ 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() @@ -1446,8 +1446,15 @@ 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]); } -- 2.47.3