From: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
To: dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
linux-pci@vger.kernel.org, ckoenig.leichtzumerken@gmail.com,
daniel.vetter@ffwll.ch, Harry.Wentland@amd.com
Cc: ppaalanen@gmail.com, Alexander.Deucher@amd.com,
gregkh@linuxfoundation.org, helgaas@kernel.org,
Felix.Kuehling@amd.com,
"Andrey Grodzovsky" <andrey.grodzovsky@amd.com>,
"Christian König" <christian.koenig@amd.com>
Subject: [PATCH v7 13/16] drm/scheduler: Fix hang when sched_entity released
Date: Wed, 12 May 2021 10:26:45 -0400 [thread overview]
Message-ID: <20210512142648.666476-14-andrey.grodzovsky@amd.com> (raw)
In-Reply-To: <20210512142648.666476-1-andrey.grodzovsky@amd.com>
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 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);
--
2.25.1
next prev parent reply other threads:[~2021-05-12 14:27 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-12 14:26 [PATCH v7 00/16] RFC Support hot device unplug in amdgpu Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 01/16] drm/ttm: Remap all page faults to per process dummy page Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 02/16] drm/amdgpu: Split amdgpu_device_fini into early and late Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 03/16] drm/amdkfd: Split kfd suspend from device exit Andrey Grodzovsky
2021-05-12 20:33 ` Felix Kuehling
2021-05-12 20:38 ` Andrey Grodzovsky
2021-05-20 3:20 ` [PATCH] drm/amdgpu: Add early fini callback Andrey Grodzovsky
2021-05-20 3:29 ` Felix Kuehling
2021-05-20 3:58 ` Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 04/16] " Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 05/16] drm/amdgpu: Handle IOMMU enabled case Andrey Grodzovsky
2021-05-14 14:41 ` Andrey Grodzovsky
2021-05-14 16:25 ` Felix Kuehling
2021-05-14 16:26 ` Andrey Grodzovsky
2021-05-17 14:38 ` [PATCH] " Andrey Grodzovsky
2021-05-17 14:48 ` Felix Kuehling
2021-05-12 14:26 ` [PATCH v7 06/16] drm/amdgpu: Remap all page faults to per process dummy page Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 07/16] PCI: Add support for dev_groups to struct pci_driver Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 08/16] drm/amdgpu: Convert driver sysfs attributes to static attributes Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 09/16] drm/amdgpu: Guard against write accesses after device removal Andrey Grodzovsky
2021-05-12 20:17 ` Alex Deucher
2021-05-12 20:30 ` Andrey Grodzovsky
2021-05-12 20:50 ` Alex Deucher
2021-05-13 14:47 ` Andrey Grodzovsky
2021-05-13 14:54 ` Alex Deucher
2021-05-12 14:26 ` [PATCH v7 10/16] drm/sched: Make timeout timer rearm conditional Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 11/16] drm/amdgpu: Prevent any job recoveries after device is unplugged Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 12/16] drm/amdgpu: Fix hang on device removal Andrey Grodzovsky
2021-05-14 14:42 ` Andrey Grodzovsky
2021-05-17 14:40 ` Andrey Grodzovsky
2021-05-17 17:39 ` Alex Deucher
2021-05-17 19:39 ` Christian König
2021-05-17 19:46 ` Andrey Grodzovsky
2021-05-17 19:54 ` Christian König
2021-05-12 14:26 ` Andrey Grodzovsky [this message]
2021-05-18 14:07 ` [PATCH v7 13/16] drm/scheduler: Fix hang when sched_entity released Christian König
2021-05-18 15:03 ` Andrey Grodzovsky
2021-05-18 15:15 ` Christian König
2021-05-18 16:17 ` Andrey Grodzovsky
2021-05-18 16:33 ` Christian König
2021-05-18 17:43 ` Andrey Grodzovsky
2021-05-18 18:02 ` Christian König
2021-05-18 18:09 ` Andrey Grodzovsky
2021-05-18 18:13 ` Christian König
2021-05-18 18:48 ` Andrey Grodzovsky
2021-05-18 20:56 ` Andrey Grodzovsky
2021-05-19 10:57 ` Christian König
2021-05-19 11:03 ` Andrey Grodzovsky
2021-05-19 11:46 ` Christian König
2021-05-19 11:51 ` Andrey Grodzovsky
2021-05-19 11:56 ` Christian König
2021-05-19 14:14 ` [PATCH] drm/sched: Avoid data corruptions Andrey Grodzovsky
2021-05-19 14:15 ` Christian König
2021-05-12 14:26 ` [PATCH v7 14/16] drm/amd/display: Remove superfluous drm_mode_config_cleanup Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 15/16] drm/amdgpu: Verify DMA opearations from device are done Andrey Grodzovsky
2021-05-12 14:26 ` [PATCH v7 16/16] drm/amdgpu: Unmap all MMIO mappings Andrey Grodzovsky
2021-05-14 14:42 ` Andrey Grodzovsky
2021-05-17 14:41 ` Andrey Grodzovsky
2021-05-17 17:43 ` Alex Deucher
2021-05-17 18:46 ` Andrey Grodzovsky
2021-05-17 18:56 ` Alex Deucher
2021-05-17 19:22 ` Andrey Grodzovsky
2021-05-17 19:31 ` [PATCH] " Andrey Grodzovsky
2021-05-18 14:01 ` Andrey Grodzovsky
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