Am 29.04.21 um 19:06 schrieb Andrey Grodzovsky:
On 2021-04-29 3:18 a.m., Christian König wrote:
I need to take another look at this part when I don't have a massive headache any more.
Maybe split the patch set up into different parts, something like:
- Adding general infrastructure.
- Making sure all memory is unpolated.
- Job and fence handling
I am not sure you mean this patch here, maybe another one ? Also note you already RBed it.
No what I meant was to send out the patches before this one as #1 and #2.
That is the easier stuff which can easily go into the drm-misc-next or amd-staging-drm-next branch.
The scheduler stuff certainly need to go into drm-misc-next.
Christian.
Andrey
Christian.
Am 28.04.21 um 17:11 schrieb Andrey Grodzovsky:
Problem: If scheduler is already stopped by the time sched_entity is released and entity's job_queue not empty I encountred a hang in drm_sched_entity_flush. This is because drm_sched_entity_is_idle never becomes false.
Fix: In drm_sched_fini detach all sched_entities from the scheduler's run queues. This will satisfy drm_sched_entity_is_idle. Also wakeup all those processes stuck in sched_entity flushing as the scheduler main thread which wakes them up is stopped by now.
v2: Reverse order of drm_sched_rq_remove_entity and marking s_entity as stopped to prevent reinserion back to rq due to race.
v3: Drop drm_sched_rq_remove_entity, only modify entity->stopped and check for it in drm_sched_entity_is_idle
Signed-off-by: Andrey Grodzovsky andrey.grodzovsky@amd.com Reviewed-by: Christian König christian.koenig@amd.com
drivers/gpu/drm/scheduler/sched_entity.c | 3 ++- drivers/gpu/drm/scheduler/sched_main.c | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index f0790e9471d1..cb58f692dad9 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -116,7 +116,8 @@ static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity) rmb(); /* for list_empty to work without lock */ if (list_empty(&entity->list) || - spsc_queue_count(&entity->job_queue) == 0) + spsc_queue_count(&entity->job_queue) == 0 || + entity->stopped) return true; return false; diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 908b0b56032d..ba087354d0a8 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -897,9 +897,33 @@ EXPORT_SYMBOL(drm_sched_init); */ void drm_sched_fini(struct drm_gpu_scheduler *sched) { + struct drm_sched_entity *s_entity; + int i;
if (sched->thread) kthread_stop(sched->thread); + for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { + struct drm_sched_rq *rq = &sched->sched_rq[i];
+ if (!rq) + continue;
+ spin_lock(&rq->lock); + list_for_each_entry(s_entity, &rq->entities, list) + /* + * Prevents reinsertion and marks job_queue as idle, + * it will removed from rq in drm_sched_entity_fini + * eventually + */ + s_entity->stopped = true; + spin_unlock(&rq->lock);
+ }
+ /* Wakeup everyone stuck in drm_sched_entity_flush for this scheduler */ + wake_up_all(&sched->job_scheduled);
/* Confirm no work left behind accessing device structures */ cancel_delayed_work_sync(&sched->work_tdr);