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author | Andrey Grodzovsky <andrey.grodzovsky@amd.com> | 2021-05-12 17:26:45 +0300 |
---|---|---|
committer | Andrey Grodzovsky <andrey.grodzovsky@amd.com> | 2021-05-20 06:50:28 +0300 |
commit | c61cdbdbffc169dc7f1e6fe94dfffaf574fe672a (patch) | |
tree | 85afb04a7616d4cb2ba53226779f5cb2f3410ac6 /drivers/gpu/drm/scheduler | |
parent | 54a85db8dea486c89467abe7540100a41bcc9b74 (diff) | |
download | linux-c61cdbdbffc169dc7f1e6fe94dfffaf574fe672a.tar.xz |
drm/scheduler: Fix hang when sched_entity released
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>
Link: https://patchwork.freedesktop.org/patch/msgid/20210512142648.666476-14-andrey.grodzovsky@amd.com
Diffstat (limited to 'drivers/gpu/drm/scheduler')
-rw-r--r-- | drivers/gpu/drm/scheduler/sched_entity.c | 3 | ||||
-rw-r--r-- | drivers/gpu/drm/scheduler/sched_main.c | 24 |
2 files changed, 26 insertions, 1 deletions
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 0249c7450188..2e93e881b65f 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 8d1211e87101..a2a953693b45 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -898,9 +898,33 @@ 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); |