[PATCH v4 1/2] drm/sched: Refactor ring mirror list handling.

[PATCH v4 1/2] drm/sched: Refactor ring mirror list handling.

[Andrey Grodzovsky]

Decauple sched threads stop and start and ring mirror
list handling from the policy of what to do about the
guilty jobs.
When stoppping the sched thread and detaching sched fences
from non signaled HW fenes wait for all signaled HW fences
to complete before rerunning the jobs.

v2: Fix resubmission of guilty job into HW after refactoring.

v4:
Full restart for all the jobs, not only from guilty ring.
Extract karma increase into standalone function.

Suggested-by: Christian Koenig <Christian.Koenig@amd.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  17 +--
 drivers/gpu/drm/etnaviv/etnaviv_sched.c    |   8 +-
 drivers/gpu/drm/scheduler/sched_main.c     | 164 +++++++++++++++++------------
 drivers/gpu/drm/v3d/v3d_sched.c            |   9 +-
 include/drm/gpu_scheduler.h                |   9 +-
 5 files changed, 118 insertions(+), 89 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 8a078f4..8ac4f43 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3298,12 +3298,7 @@ static int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
 		if (!ring || !ring->sched.thread)
 			continue;
 
-		kthread_park(ring->sched.thread);
-
-		if (job && job->base.sched != &ring->sched)
-			continue;
-
-		drm_sched_hw_job_reset(&ring->sched, job ? &job->base : NULL);
+		drm_sched_stop(&ring->sched, job ? &job->base : NULL);
 
 		/* after all hw jobs are reset, hw fence is meaningless, so force_completion */
 		amdgpu_fence_driver_force_completion(ring);
@@ -3454,14 +3449,10 @@ static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev,
 		if (!ring || !ring->sched.thread)
 			continue;
 
-		/* only need recovery sched of the given job's ring
-		 * or all rings (in the case @job is NULL)
-		 * after above amdgpu_reset accomplished
-		 */
-		if ((!job || job->base.sched == &ring->sched) && !adev->asic_reset_res)
-			drm_sched_job_recovery(&ring->sched);
+		if (!adev->asic_reset_res)
+			drm_sched_resubmit_jobs(&ring->sched);
 
-		kthread_unpark(ring->sched.thread);
+		drm_sched_start(&ring->sched, !adev->asic_reset_res);
 	}
 
 	if (!amdgpu_device_has_dc_support(adev)) {
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
index 49a6763..d7075cd 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
@@ -109,16 +109,16 @@ static void etnaviv_sched_timedout_job(struct drm_sched_job *sched_job)
 	}
 
 	/* block scheduler */
-	kthread_park(gpu->sched.thread);
-	drm_sched_hw_job_reset(&gpu->sched, sched_job);
+	drm_sched_stop(&gpu->sched, sched_job);
 
 	/* get the GPU back into the init state */
 	etnaviv_core_dump(gpu);
 	etnaviv_gpu_recover_hang(gpu);
 
+	drm_sched_resubmit_jobs(&gpu->sched);
+
 	/* restart scheduler after GPU is usable again */
-	drm_sched_job_recovery(&gpu->sched);
-	kthread_unpark(gpu->sched.thread);
+	drm_sched_start(&gpu->sched, true);
 }
 
 static void etnaviv_sched_free_job(struct drm_sched_job *sched_job)
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index dbb6906..1cf9541 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -60,8 +60,6 @@
 
 static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb);
 
-static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job);
-
 /**
  * drm_sched_rq_init - initialize a given run queue struct
  *
@@ -335,6 +333,41 @@ static void drm_sched_job_timedout(struct work_struct *work)
 	spin_unlock_irqrestore(&sched->job_list_lock, flags);
 }
 
+static void drm_sched_increase_karma(struct drm_sched_job *bad)
+{
+	int i;
+	struct drm_sched_entity *tmp;
+	struct drm_sched_entity *entity;
+	struct drm_gpu_scheduler *sched = bad->sched;
+
+	/* don't increase @bad's karma if it's from KERNEL RQ,
+	 * because sometimes GPU hang would cause kernel jobs (like VM updating jobs)
+	 * corrupt but keep in mind that kernel jobs always considered good.
+	 */
+	if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
+		atomic_inc(&bad->karma);
+		for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL;
+		     i++) {
+			struct drm_sched_rq *rq = &sched->sched_rq[i];
+
+			spin_lock(&rq->lock);
+			list_for_each_entry_safe(entity, tmp, &rq->entities, list) {
+				if (bad->s_fence->scheduled.context ==
+				    entity->fence_context) {
+					if (atomic_read(&bad->karma) >
+					    bad->sched->hang_limit)
+						if (entity->guilty)
+							atomic_set(entity->guilty, 1);
+					break;
+				}
+			}
+			spin_unlock(&rq->lock);
+			if (&entity->list != &rq->entities)
+				break;
+		}
+	}
+}
+
 /**
  * drm_sched_hw_job_reset - stop the scheduler if it contains the bad job
  *
@@ -342,12 +375,15 @@ static void drm_sched_job_timedout(struct work_struct *work)
  * @bad: bad scheduler job
  *
  */
-void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
+void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
 {
 	struct drm_sched_job *s_job;
-	struct drm_sched_entity *entity, *tmp;
 	unsigned long flags;
-	int i;
+	struct list_head wait_list;
+
+	kthread_park(sched->thread);
+
+	INIT_LIST_HEAD(&wait_list);
 
 	spin_lock_irqsave(&sched->job_list_lock, flags);
 	list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, node) {
@@ -357,35 +393,28 @@ void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_jo
 			dma_fence_put(s_job->s_fence->parent);
 			s_job->s_fence->parent = NULL;
 			atomic_dec(&sched->hw_rq_count);
+		} else {
+			/* TODO Is it get/put neccessey here ? */
+			dma_fence_get(&s_job->s_fence->finished);
+			list_add(&s_job->finish_node, &wait_list);
 		}
 	}
 	spin_unlock_irqrestore(&sched->job_list_lock, flags);
 
-	if (bad && bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
-		atomic_inc(&bad->karma);
-		/* don't increase @bad's karma if it's from KERNEL RQ,
-		 * becuase sometimes GPU hang would cause kernel jobs (like VM updating jobs)
-		 * corrupt but keep in mind that kernel jobs always considered good.
-		 */
-		for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL; i++ ) {
-			struct drm_sched_rq *rq = &sched->sched_rq[i];
-
-			spin_lock(&rq->lock);
-			list_for_each_entry_safe(entity, tmp, &rq->entities, list) {
-				if (bad->s_fence->scheduled.context == entity->fence_context) {
-				    if (atomic_read(&bad->karma) > bad->sched->hang_limit)
-						if (entity->guilty)
-							atomic_set(entity->guilty, 1);
-					break;
-				}
-			}
-			spin_unlock(&rq->lock);
-			if (&entity->list != &rq->entities)
-				break;
-		}
+	/*
+	 * Verify all the signaled jobs in mirror list are removed from the ring
+	 * We rely on the fact that any finish_work in progress will wait for this
+	 * handler to complete before releasing all of the jobs we iterate.
+	 */
+	list_for_each_entry(s_job, &wait_list, finish_node) {
+		dma_fence_wait(&s_job->s_fence->finished, false);
+		dma_fence_put(&s_job->s_fence->finished);
 	}
+
+	if (bad)
+		drm_sched_increase_karma(bad);
 }
-EXPORT_SYMBOL(drm_sched_hw_job_reset);
+EXPORT_SYMBOL(drm_sched_stop);
 
 /**
  * drm_sched_job_recovery - recover jobs after a reset
@@ -393,33 +422,21 @@ EXPORT_SYMBOL(drm_sched_hw_job_reset);
  * @sched: scheduler instance
  *
  */
-void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
+void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery)
 {
 	struct drm_sched_job *s_job, *tmp;
-	bool found_guilty = false;
 	unsigned long flags;
 	int r;
 
+	if (!full_recovery)
+		goto unpark;
+
 	spin_lock_irqsave(&sched->job_list_lock, flags);
 	list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
 		struct drm_sched_fence *s_fence = s_job->s_fence;
-		struct dma_fence *fence;
-		uint64_t guilty_context;
-
-		if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) {
-			found_guilty = true;
-			guilty_context = s_job->s_fence->scheduled.context;
-		}
-
-		if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
-			dma_fence_set_error(&s_fence->finished, -ECANCELED);
-
-		spin_unlock_irqrestore(&sched->job_list_lock, flags);
-		fence = sched->ops->run_job(s_job);
-		atomic_inc(&sched->hw_rq_count);
+		struct dma_fence *fence = s_job->s_fence->parent;
 
 		if (fence) {
-			s_fence->parent = dma_fence_get(fence);
 			r = dma_fence_add_callback(fence, &s_fence->cb,
 						   drm_sched_process_job);
 			if (r == -ENOENT)
@@ -427,18 +444,47 @@ void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
 			else if (r)
 				DRM_ERROR("fence add callback failed (%d)\n",
 					  r);
-			dma_fence_put(fence);
-		} else {
-			if (s_fence->finished.error < 0)
-				drm_sched_expel_job_unlocked(s_job);
+		} else
 			drm_sched_process_job(NULL, &s_fence->cb);
-		}
-		spin_lock_irqsave(&sched->job_list_lock, flags);
 	}
+
 	drm_sched_start_timeout(sched);
 	spin_unlock_irqrestore(&sched->job_list_lock, flags);
+
+unpark:
+	kthread_unpark(sched->thread);
 }
-EXPORT_SYMBOL(drm_sched_job_recovery);
+EXPORT_SYMBOL(drm_sched_start);
+
+/**
+ * drm_sched_resubmit_jobs - helper to relunch job from mirror ring list
+ *
+ * @sched: scheduler instance
+ *
+ */
+void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched)
+{
+	struct drm_sched_job *s_job, *tmp;
+	uint64_t guilty_context;
+	bool found_guilty = false;
+
+	/*TODO DO we need spinlock here ? */
+	list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
+		struct drm_sched_fence *s_fence = s_job->s_fence;
+
+		if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) {
+			found_guilty = true;
+			guilty_context = s_job->s_fence->scheduled.context;
+		}
+
+		if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
+			dma_fence_set_error(&s_fence->finished, -ECANCELED);
+
+		s_job->s_fence->parent = sched->ops->run_job(s_job);
+		atomic_inc(&sched->hw_rq_count);
+	}
+}
+EXPORT_SYMBOL(drm_sched_resubmit_jobs);
 
 /**
  * drm_sched_job_init - init a scheduler job
@@ -634,26 +680,14 @@ static int drm_sched_main(void *param)
 				DRM_ERROR("fence add callback failed (%d)\n",
 					  r);
 			dma_fence_put(fence);
-		} else {
-			if (s_fence->finished.error < 0)
-				drm_sched_expel_job_unlocked(sched_job);
+		} else
 			drm_sched_process_job(NULL, &s_fence->cb);
-		}
 
 		wake_up(&sched->job_scheduled);
 	}
 	return 0;
 }
 
-static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job)
-{
-	struct drm_gpu_scheduler *sched = s_job->sched;
-
-	spin_lock(&sched->job_list_lock);
-	list_del_init(&s_job->node);
-	spin_unlock(&sched->job_list_lock);
-}
-
 /**
  * drm_sched_init - Init a gpu scheduler instance
  *
diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
index 445b2ef..aaa10b0 100644
--- a/drivers/gpu/drm/v3d/v3d_sched.c
+++ b/drivers/gpu/drm/v3d/v3d_sched.c
@@ -178,18 +178,19 @@ v3d_job_timedout(struct drm_sched_job *sched_job)
 	for (q = 0; q < V3D_MAX_QUEUES; q++) {
 		struct drm_gpu_scheduler *sched = &v3d->queue[q].sched;
 
-		kthread_park(sched->thread);
-		drm_sched_hw_job_reset(sched, (sched_job->sched == sched ?
+		drm_sched_stop(sched, (sched_job->sched == sched ?
 					       sched_job : NULL));
 	}
 
 	/* get the GPU back into the init state */
 	v3d_reset(v3d);
 
+	for (q = 0; q < V3D_MAX_QUEUES; q++)
+		drm_sched_resubmit_jobs(sched_job->sched);
+
 	/* Unblock schedulers and restart their jobs. */
 	for (q = 0; q < V3D_MAX_QUEUES; q++) {
-		drm_sched_job_recovery(&v3d->queue[q].sched);
-		kthread_unpark(v3d->queue[q].sched.thread);
+		drm_sched_start(&v3d->queue[q].sched, true);
 	}
 
 	mutex_unlock(&v3d->reset_lock);
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index 47e1979..441384c 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -175,6 +175,7 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
  *               finished to remove the job from the
  *               @drm_gpu_scheduler.ring_mirror_list.
  * @node: used to append this struct to the @drm_gpu_scheduler.ring_mirror_list.
+ * @finish_node: used in a list to wait on before resetting the scheduler
  * @id: a unique id assigned to each job scheduled on the scheduler.
  * @karma: increment on every hang caused by this job. If this exceeds the hang
  *         limit of the scheduler then the job is marked guilty and will not
@@ -193,6 +194,7 @@ struct drm_sched_job {
 	struct dma_fence_cb		finish_cb;
 	struct work_struct		finish_work;
 	struct list_head		node;
+	struct list_head		finish_node;
 	uint64_t			id;
 	atomic_t			karma;
 	enum drm_sched_priority		s_priority;
@@ -298,9 +300,10 @@ int drm_sched_job_init(struct drm_sched_job *job,
 		       void *owner);
 void drm_sched_job_cleanup(struct drm_sched_job *job);
 void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
-void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched,
-			    struct drm_sched_job *job);
-void drm_sched_job_recovery(struct drm_gpu_scheduler *sched);
+void drm_sched_stop(struct drm_gpu_scheduler *sched,
+		    struct drm_sched_job *job);
+void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery);
+void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
 bool drm_sched_dependency_optimized(struct dma_fence* fence,
 				    struct drm_sched_entity *entity);
 void drm_sched_fault(struct drm_gpu_scheduler *sched);
-- 
2.7.4

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[PATCH v4 2/2] drm/sched: Rework HW fence processing.

[Andrey Grodzovsky]

Expedite job deletion from ring mirror list to the HW fence signal
callback instead from finish_work, together with waiting for all
such fences to signal in drm_sched_stop we garantee that
already signaled job will not be processed twice.
Remove the sched finish fence callback and just submit finish_work
directly from the HW fence callback.

v2: Fix comments.

v3: Attach  hw fence cb to sched_job

Suggested-by: Christian Koenig <Christian.Koenig@amd.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
---
 drivers/gpu/drm/scheduler/sched_main.c | 55 +++++++++++++++++-----------------
 include/drm/gpu_scheduler.h            |  6 ++--
 2 files changed, 29 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 1cf9541..40df9b9 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -284,8 +284,6 @@ static void drm_sched_job_finish(struct work_struct *work)
 	cancel_delayed_work_sync(&sched->work_tdr);
 
 	spin_lock_irqsave(&sched->job_list_lock, flags);
-	/* remove job from ring_mirror_list */
-	list_del_init(&s_job->node);
 	/* queue TDR for next job */
 	drm_sched_start_timeout(sched);
 	spin_unlock_irqrestore(&sched->job_list_lock, flags);
@@ -293,22 +291,11 @@ static void drm_sched_job_finish(struct work_struct *work)
 	sched->ops->free_job(s_job);
 }
 
-static void drm_sched_job_finish_cb(struct dma_fence *f,
-				    struct dma_fence_cb *cb)
-{
-	struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
-						 finish_cb);
-	schedule_work(&job->finish_work);
-}
-
 static void drm_sched_job_begin(struct drm_sched_job *s_job)
 {
 	struct drm_gpu_scheduler *sched = s_job->sched;
 	unsigned long flags;
 
-	dma_fence_add_callback(&s_job->s_fence->finished, &s_job->finish_cb,
-			       drm_sched_job_finish_cb);
-
 	spin_lock_irqsave(&sched->job_list_lock, flags);
 	list_add_tail(&s_job->node, &sched->ring_mirror_list);
 	drm_sched_start_timeout(sched);
@@ -389,7 +376,7 @@ void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
 	list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, node) {
 		if (s_job->s_fence->parent &&
 		    dma_fence_remove_callback(s_job->s_fence->parent,
-					      &s_job->s_fence->cb)) {
+					      &s_job->cb)) {
 			dma_fence_put(s_job->s_fence->parent);
 			s_job->s_fence->parent = NULL;
 			atomic_dec(&sched->hw_rq_count);
@@ -425,31 +412,34 @@ EXPORT_SYMBOL(drm_sched_stop);
 void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery)
 {
 	struct drm_sched_job *s_job, *tmp;
-	unsigned long flags;
 	int r;
 
 	if (!full_recovery)
 		goto unpark;
 
-	spin_lock_irqsave(&sched->job_list_lock, flags);
+	/*
+	 * Locking the list is not required here as the sched thread is parked
+	 * so no new jobs are being pushed in to HW and in drm_sched_stop we
+	 * flushed all the jobs who were still in mirror list but who already
+	 * signaled and removed them self from the list. Also concurrent
+	 * GPU recovers can't run in parallel.
+	 */
 	list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
-		struct drm_sched_fence *s_fence = s_job->s_fence;
 		struct dma_fence *fence = s_job->s_fence->parent;
 
 		if (fence) {
-			r = dma_fence_add_callback(fence, &s_fence->cb,
+			r = dma_fence_add_callback(fence, &s_job->cb,
 						   drm_sched_process_job);
 			if (r == -ENOENT)
-				drm_sched_process_job(fence, &s_fence->cb);
+				drm_sched_process_job(fence, &s_job->cb);
 			else if (r)
 				DRM_ERROR("fence add callback failed (%d)\n",
 					  r);
 		} else
-			drm_sched_process_job(NULL, &s_fence->cb);
+			drm_sched_process_job(NULL, &s_job->cb);
 	}
 
 	drm_sched_start_timeout(sched);
-	spin_unlock_irqrestore(&sched->job_list_lock, flags);
 
 unpark:
 	kthread_unpark(sched->thread);
@@ -598,18 +588,27 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched)
  */
 static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb)
 {
-	struct drm_sched_fence *s_fence =
-		container_of(cb, struct drm_sched_fence, cb);
+	struct drm_sched_job *s_job = container_of(cb, struct drm_sched_job, cb);
+	struct drm_sched_fence *s_fence = s_job->s_fence;
 	struct drm_gpu_scheduler *sched = s_fence->sched;
+	unsigned long flags;
+
+	cancel_delayed_work(&sched->work_tdr);
 
-	dma_fence_get(&s_fence->finished);
 	atomic_dec(&sched->hw_rq_count);
 	atomic_dec(&sched->num_jobs);
+
+	spin_lock_irqsave(&sched->job_list_lock, flags);
+	/* remove job from ring_mirror_list */
+	list_del_init(&s_job->node);
+	spin_unlock_irqrestore(&sched->job_list_lock, flags);
+
 	drm_sched_fence_finished(s_fence);
 
 	trace_drm_sched_process_job(s_fence);
-	dma_fence_put(&s_fence->finished);
 	wake_up_interruptible(&sched->wake_up_worker);
+
+	schedule_work(&s_job->finish_work);
 }
 
 /**
@@ -672,16 +671,16 @@ static int drm_sched_main(void *param)
 
 		if (fence) {
 			s_fence->parent = dma_fence_get(fence);
-			r = dma_fence_add_callback(fence, &s_fence->cb,
+			r = dma_fence_add_callback(fence, &sched_job->cb,
 						   drm_sched_process_job);
 			if (r == -ENOENT)
-				drm_sched_process_job(fence, &s_fence->cb);
+				drm_sched_process_job(fence, &sched_job->cb);
 			else if (r)
 				DRM_ERROR("fence add callback failed (%d)\n",
 					  r);
 			dma_fence_put(fence);
 		} else
-			drm_sched_process_job(NULL, &s_fence->cb);
+			drm_sched_process_job(NULL, &sched_job->cb);
 
 		wake_up(&sched->job_scheduled);
 	}
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index 441384c..c5bbf4e 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -138,10 +138,6 @@ struct drm_sched_fence {
 	struct dma_fence		finished;
 
         /**
-         * @cb: the callback for the parent fence below.
-         */
-	struct dma_fence_cb		cb;
-        /**
          * @parent: the fence returned by &drm_sched_backend_ops.run_job
          * when scheduling the job on hardware. We signal the
          * &drm_sched_fence.finished fence once parent is signalled.
@@ -182,6 +178,7 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
  *         be scheduled further.
  * @s_priority: the priority of the job.
  * @entity: the entity to which this job belongs.
+ * @cb: the callback for the parent fence in s_fence.
  *
  * A job is created by the driver using drm_sched_job_init(), and
  * should call drm_sched_entity_push_job() once it wants the scheduler
@@ -199,6 +196,7 @@ struct drm_sched_job {
 	atomic_t			karma;
 	enum drm_sched_priority		s_priority;
 	struct drm_sched_entity  *entity;
+	struct dma_fence_cb		cb;
 };
 
 static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
-- 
2.7.4

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Re: [PATCH v4 1/2] drm/sched: Refactor ring mirror list handling.

[Christian König]

Am 17.12.18 um 20:51 schrieb Andrey Grodzovsky:
> Decauple sched threads stop and start and ring mirror
> list handling from the policy of what to do about the
> guilty jobs.
> When stoppping the sched thread and detaching sched fences
> from non signaled HW fenes wait for all signaled HW fences
> to complete before rerunning the jobs.
>
> v2: Fix resubmission of guilty job into HW after refactoring.
>
> v4:
> Full restart for all the jobs, not only from guilty ring.
> Extract karma increase into standalone function.
>
> Suggested-by: Christian Koenig <Christian.Koenig@amd.com>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  17 +--
>   drivers/gpu/drm/etnaviv/etnaviv_sched.c    |   8 +-
>   drivers/gpu/drm/scheduler/sched_main.c     | 164 +++++++++++++++++------------
>   drivers/gpu/drm/v3d/v3d_sched.c            |   9 +-
>   include/drm/gpu_scheduler.h                |   9 +-
>   5 files changed, 118 insertions(+), 89 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 8a078f4..8ac4f43 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3298,12 +3298,7 @@ static int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
>   		if (!ring || !ring->sched.thread)
>   			continue;
>   
> -		kthread_park(ring->sched.thread);
> -
> -		if (job && job->base.sched != &ring->sched)
> -			continue;
> -
> -		drm_sched_hw_job_reset(&ring->sched, job ? &job->base : NULL);
> +		drm_sched_stop(&ring->sched, job ? &job->base : NULL);
>   
>   		/* after all hw jobs are reset, hw fence is meaningless, so force_completion */
>   		amdgpu_fence_driver_force_completion(ring);
> @@ -3454,14 +3449,10 @@ static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev,
>   		if (!ring || !ring->sched.thread)
>   			continue;
>   
> -		/* only need recovery sched of the given job's ring
> -		 * or all rings (in the case @job is NULL)
> -		 * after above amdgpu_reset accomplished
> -		 */
> -		if ((!job || job->base.sched == &ring->sched) && !adev->asic_reset_res)
> -			drm_sched_job_recovery(&ring->sched);
> +		if (!adev->asic_reset_res)
> +			drm_sched_resubmit_jobs(&ring->sched);
>   
> -		kthread_unpark(ring->sched.thread);
> +		drm_sched_start(&ring->sched, !adev->asic_reset_res);
>   	}
>   
>   	if (!amdgpu_device_has_dc_support(adev)) {
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> index 49a6763..d7075cd 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> @@ -109,16 +109,16 @@ static void etnaviv_sched_timedout_job(struct drm_sched_job *sched_job)
>   	}
>   
>   	/* block scheduler */
> -	kthread_park(gpu->sched.thread);
> -	drm_sched_hw_job_reset(&gpu->sched, sched_job);
> +	drm_sched_stop(&gpu->sched, sched_job);
>   
>   	/* get the GPU back into the init state */
>   	etnaviv_core_dump(gpu);
>   	etnaviv_gpu_recover_hang(gpu);
>   
> +	drm_sched_resubmit_jobs(&gpu->sched);
> +
>   	/* restart scheduler after GPU is usable again */
> -	drm_sched_job_recovery(&gpu->sched);
> -	kthread_unpark(gpu->sched.thread);
> +	drm_sched_start(&gpu->sched, true);
>   }
>   
>   static void etnaviv_sched_free_job(struct drm_sched_job *sched_job)
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index dbb6906..1cf9541 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -60,8 +60,6 @@
>   
>   static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb);
>   
> -static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job);
> -
>   /**
>    * drm_sched_rq_init - initialize a given run queue struct
>    *
> @@ -335,6 +333,41 @@ static void drm_sched_job_timedout(struct work_struct *work)
>   	spin_unlock_irqrestore(&sched->job_list_lock, flags);
>   }
>   
> +static void drm_sched_increase_karma(struct drm_sched_job *bad)
> +{
> +	int i;
> +	struct drm_sched_entity *tmp;
> +	struct drm_sched_entity *entity;
> +	struct drm_gpu_scheduler *sched = bad->sched;
> +
> +	/* don't increase @bad's karma if it's from KERNEL RQ,
> +	 * because sometimes GPU hang would cause kernel jobs (like VM updating jobs)
> +	 * corrupt but keep in mind that kernel jobs always considered good.
> +	 */
> +	if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
> +		atomic_inc(&bad->karma);
> +		for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL;
> +		     i++) {
> +			struct drm_sched_rq *rq = &sched->sched_rq[i];
> +
> +			spin_lock(&rq->lock);
> +			list_for_each_entry_safe(entity, tmp, &rq->entities, list) {
> +				if (bad->s_fence->scheduled.context ==
> +				    entity->fence_context) {
> +					if (atomic_read(&bad->karma) >
> +					    bad->sched->hang_limit)
> +						if (entity->guilty)
> +							atomic_set(entity->guilty, 1);
> +					break;
> +				}
> +			}
> +			spin_unlock(&rq->lock);
> +			if (&entity->list != &rq->entities)
> +				break;
> +		}
> +	}
> +}
> +
>   /**
>    * drm_sched_hw_job_reset - stop the scheduler if it contains the bad job
>    *
> @@ -342,12 +375,15 @@ static void drm_sched_job_timedout(struct work_struct *work)
>    * @bad: bad scheduler job
>    *
>    */
> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
> +void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
>   {
>   	struct drm_sched_job *s_job;
> -	struct drm_sched_entity *entity, *tmp;
>   	unsigned long flags;
> -	int i;
> +	struct list_head wait_list;
> +
> +	kthread_park(sched->thread);
> +
> +	INIT_LIST_HEAD(&wait_list);
>   
>   	spin_lock_irqsave(&sched->job_list_lock, flags);
>   	list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, node) {
> @@ -357,35 +393,28 @@ void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_jo
>   			dma_fence_put(s_job->s_fence->parent);
>   			s_job->s_fence->parent = NULL;
>   			atomic_dec(&sched->hw_rq_count);
> +		} else {
> +			/* TODO Is it get/put neccessey here ? */
> +			dma_fence_get(&s_job->s_fence->finished);
> +			list_add(&s_job->finish_node, &wait_list);
>   		}
>   	}
>   	spin_unlock_irqrestore(&sched->job_list_lock, flags);
>   
> -	if (bad && bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
> -		atomic_inc(&bad->karma);
> -		/* don't increase @bad's karma if it's from KERNEL RQ,
> -		 * becuase sometimes GPU hang would cause kernel jobs (like VM updating jobs)
> -		 * corrupt but keep in mind that kernel jobs always considered good.
> -		 */
> -		for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL; i++ ) {
> -			struct drm_sched_rq *rq = &sched->sched_rq[i];
> -
> -			spin_lock(&rq->lock);
> -			list_for_each_entry_safe(entity, tmp, &rq->entities, list) {
> -				if (bad->s_fence->scheduled.context == entity->fence_context) {
> -				    if (atomic_read(&bad->karma) > bad->sched->hang_limit)
> -						if (entity->guilty)
> -							atomic_set(entity->guilty, 1);
> -					break;
> -				}
> -			}
> -			spin_unlock(&rq->lock);
> -			if (&entity->list != &rq->entities)
> -				break;
> -		}
> +	/*
> +	 * Verify all the signaled jobs in mirror list are removed from the ring
> +	 * We rely on the fact that any finish_work in progress will wait for this
> +	 * handler to complete before releasing all of the jobs we iterate.
> +	 */
> +	list_for_each_entry(s_job, &wait_list, finish_node) {
> +		dma_fence_wait(&s_job->s_fence->finished, false);
> +		dma_fence_put(&s_job->s_fence->finished);
>   	}

Mhm, thinking more about it that approach won't work.

Only the scheduler instance with the timeout will block on the GPU reset 
to finish before freeing up s_job.

The job_list_lock will protect us, but as soon as that is dropped we are 
potentially working with freed up jobs here.

Maybe your idea of just waiting for the last finished fence to signal 
wasn't so bad after all. This way you only need to grab the last one and 
wait for it.

And since fences are reference counted we also don't run into any 
problems because of that.

> +
> +	if (bad)
> +		drm_sched_increase_karma(bad);

Better export drm_sched_increase_karma() and let the drivers call that 
implicitly.

Regards,
Christian.

>   }
> -EXPORT_SYMBOL(drm_sched_hw_job_reset);
> +EXPORT_SYMBOL(drm_sched_stop);
>   
>   /**
>    * drm_sched_job_recovery - recover jobs after a reset
> @@ -393,33 +422,21 @@ EXPORT_SYMBOL(drm_sched_hw_job_reset);
>    * @sched: scheduler instance
>    *
>    */
> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery)
>   {
>   	struct drm_sched_job *s_job, *tmp;
> -	bool found_guilty = false;
>   	unsigned long flags;
>   	int r;
>   
> +	if (!full_recovery)
> +		goto unpark;
> +
>   	spin_lock_irqsave(&sched->job_list_lock, flags);
>   	list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
>   		struct drm_sched_fence *s_fence = s_job->s_fence;
> -		struct dma_fence *fence;
> -		uint64_t guilty_context;
> -
> -		if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) {
> -			found_guilty = true;
> -			guilty_context = s_job->s_fence->scheduled.context;
> -		}
> -
> -		if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
> -			dma_fence_set_error(&s_fence->finished, -ECANCELED);
> -
> -		spin_unlock_irqrestore(&sched->job_list_lock, flags);
> -		fence = sched->ops->run_job(s_job);
> -		atomic_inc(&sched->hw_rq_count);
> +		struct dma_fence *fence = s_job->s_fence->parent;
>   
>   		if (fence) {
> -			s_fence->parent = dma_fence_get(fence);
>   			r = dma_fence_add_callback(fence, &s_fence->cb,
>   						   drm_sched_process_job);
>   			if (r == -ENOENT)
> @@ -427,18 +444,47 @@ void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
>   			else if (r)
>   				DRM_ERROR("fence add callback failed (%d)\n",
>   					  r);
> -			dma_fence_put(fence);
> -		} else {
> -			if (s_fence->finished.error < 0)
> -				drm_sched_expel_job_unlocked(s_job);
> +		} else
>   			drm_sched_process_job(NULL, &s_fence->cb);
> -		}
> -		spin_lock_irqsave(&sched->job_list_lock, flags);
>   	}
> +
>   	drm_sched_start_timeout(sched);
>   	spin_unlock_irqrestore(&sched->job_list_lock, flags);
> +
> +unpark:
> +	kthread_unpark(sched->thread);
>   }
> -EXPORT_SYMBOL(drm_sched_job_recovery);
> +EXPORT_SYMBOL(drm_sched_start);
> +
> +/**
> + * drm_sched_resubmit_jobs - helper to relunch job from mirror ring list
> + *
> + * @sched: scheduler instance
> + *
> + */
> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched)
> +{
> +	struct drm_sched_job *s_job, *tmp;
> +	uint64_t guilty_context;
> +	bool found_guilty = false;
> +
> +	/*TODO DO we need spinlock here ? */
> +	list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
> +		struct drm_sched_fence *s_fence = s_job->s_fence;
> +
> +		if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) {
> +			found_guilty = true;
> +			guilty_context = s_job->s_fence->scheduled.context;
> +		}
> +
> +		if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
> +			dma_fence_set_error(&s_fence->finished, -ECANCELED);
> +
> +		s_job->s_fence->parent = sched->ops->run_job(s_job);
> +		atomic_inc(&sched->hw_rq_count);
> +	}
> +}
> +EXPORT_SYMBOL(drm_sched_resubmit_jobs);
>   
>   /**
>    * drm_sched_job_init - init a scheduler job
> @@ -634,26 +680,14 @@ static int drm_sched_main(void *param)
>   				DRM_ERROR("fence add callback failed (%d)\n",
>   					  r);
>   			dma_fence_put(fence);
> -		} else {
> -			if (s_fence->finished.error < 0)
> -				drm_sched_expel_job_unlocked(sched_job);
> +		} else
>   			drm_sched_process_job(NULL, &s_fence->cb);
> -		}
>   
>   		wake_up(&sched->job_scheduled);
>   	}
>   	return 0;
>   }
>   
> -static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job)
> -{
> -	struct drm_gpu_scheduler *sched = s_job->sched;
> -
> -	spin_lock(&sched->job_list_lock);
> -	list_del_init(&s_job->node);
> -	spin_unlock(&sched->job_list_lock);
> -}
> -
>   /**
>    * drm_sched_init - Init a gpu scheduler instance
>    *
> diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
> index 445b2ef..aaa10b0 100644
> --- a/drivers/gpu/drm/v3d/v3d_sched.c
> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
> @@ -178,18 +178,19 @@ v3d_job_timedout(struct drm_sched_job *sched_job)
>   	for (q = 0; q < V3D_MAX_QUEUES; q++) {
>   		struct drm_gpu_scheduler *sched = &v3d->queue[q].sched;
>   
> -		kthread_park(sched->thread);
> -		drm_sched_hw_job_reset(sched, (sched_job->sched == sched ?
> +		drm_sched_stop(sched, (sched_job->sched == sched ?
>   					       sched_job : NULL));
>   	}
>   
>   	/* get the GPU back into the init state */
>   	v3d_reset(v3d);
>   
> +	for (q = 0; q < V3D_MAX_QUEUES; q++)
> +		drm_sched_resubmit_jobs(sched_job->sched);
> +
>   	/* Unblock schedulers and restart their jobs. */
>   	for (q = 0; q < V3D_MAX_QUEUES; q++) {
> -		drm_sched_job_recovery(&v3d->queue[q].sched);
> -		kthread_unpark(v3d->queue[q].sched.thread);
> +		drm_sched_start(&v3d->queue[q].sched, true);
>   	}
>   
>   	mutex_unlock(&v3d->reset_lock);
> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
> index 47e1979..441384c 100644
> --- a/include/drm/gpu_scheduler.h
> +++ b/include/drm/gpu_scheduler.h
> @@ -175,6 +175,7 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
>    *               finished to remove the job from the
>    *               @drm_gpu_scheduler.ring_mirror_list.
>    * @node: used to append this struct to the @drm_gpu_scheduler.ring_mirror_list.
> + * @finish_node: used in a list to wait on before resetting the scheduler
>    * @id: a unique id assigned to each job scheduled on the scheduler.
>    * @karma: increment on every hang caused by this job. If this exceeds the hang
>    *         limit of the scheduler then the job is marked guilty and will not
> @@ -193,6 +194,7 @@ struct drm_sched_job {
>   	struct dma_fence_cb		finish_cb;
>   	struct work_struct		finish_work;
>   	struct list_head		node;
> +	struct list_head		finish_node;
>   	uint64_t			id;
>   	atomic_t			karma;
>   	enum drm_sched_priority		s_priority;
> @@ -298,9 +300,10 @@ int drm_sched_job_init(struct drm_sched_job *job,
>   		       void *owner);
>   void drm_sched_job_cleanup(struct drm_sched_job *job);
>   void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched,
> -			    struct drm_sched_job *job);
> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched);
> +void drm_sched_stop(struct drm_gpu_scheduler *sched,
> +		    struct drm_sched_job *job);
> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery);
> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
>   bool drm_sched_dependency_optimized(struct dma_fence* fence,
>   				    struct drm_sched_entity *entity);
>   void drm_sched_fault(struct drm_gpu_scheduler *sched);

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Re: [PATCH v4 1/2] drm/sched: Refactor ring mirror list handling.

[Grodzovsky, Andrey]

On 12/19/2018 11:21 AM, Christian König wrote:
> Am 17.12.18 um 20:51 schrieb Andrey Grodzovsky:
>> Decauple sched threads stop and start and ring mirror
>> list handling from the policy of what to do about the
>> guilty jobs.
>> When stoppping the sched thread and detaching sched fences
>> from non signaled HW fenes wait for all signaled HW fences
>> to complete before rerunning the jobs.
>>
>> v2: Fix resubmission of guilty job into HW after refactoring.
>>
>> v4:
>> Full restart for all the jobs, not only from guilty ring.
>> Extract karma increase into standalone function.
>>
>> Suggested-by: Christian Koenig <Christian.Koenig@amd.com>
>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  17 +--
>>   drivers/gpu/drm/etnaviv/etnaviv_sched.c    |   8 +-
>>   drivers/gpu/drm/scheduler/sched_main.c     | 164 
>> +++++++++++++++++------------
>>   drivers/gpu/drm/v3d/v3d_sched.c            |   9 +-
>>   include/drm/gpu_scheduler.h                |   9 +-
>>   5 files changed, 118 insertions(+), 89 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 8a078f4..8ac4f43 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -3298,12 +3298,7 @@ static int amdgpu_device_pre_asic_reset(struct 
>> amdgpu_device *adev,
>>           if (!ring || !ring->sched.thread)
>>               continue;
>>   -        kthread_park(ring->sched.thread);
>> -
>> -        if (job && job->base.sched != &ring->sched)
>> -            continue;
>> -
>> -        drm_sched_hw_job_reset(&ring->sched, job ? &job->base : NULL);
>> +        drm_sched_stop(&ring->sched, job ? &job->base : NULL);
>>             /* after all hw jobs are reset, hw fence is meaningless, 
>> so force_completion */
>>           amdgpu_fence_driver_force_completion(ring);
>> @@ -3454,14 +3449,10 @@ static void 
>> amdgpu_device_post_asic_reset(struct amdgpu_device *adev,
>>           if (!ring || !ring->sched.thread)
>>               continue;
>>   -        /* only need recovery sched of the given job's ring
>> -         * or all rings (in the case @job is NULL)
>> -         * after above amdgpu_reset accomplished
>> -         */
>> -        if ((!job || job->base.sched == &ring->sched) && 
>> !adev->asic_reset_res)
>> -            drm_sched_job_recovery(&ring->sched);
>> +        if (!adev->asic_reset_res)
>> +            drm_sched_resubmit_jobs(&ring->sched);
>>   -        kthread_unpark(ring->sched.thread);
>> +        drm_sched_start(&ring->sched, !adev->asic_reset_res);
>>       }
>>         if (!amdgpu_device_has_dc_support(adev)) {
>> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c 
>> b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>> index 49a6763..d7075cd 100644
>> --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>> @@ -109,16 +109,16 @@ static void etnaviv_sched_timedout_job(struct 
>> drm_sched_job *sched_job)
>>       }
>>         /* block scheduler */
>> -    kthread_park(gpu->sched.thread);
>> -    drm_sched_hw_job_reset(&gpu->sched, sched_job);
>> +    drm_sched_stop(&gpu->sched, sched_job);
>>         /* get the GPU back into the init state */
>>       etnaviv_core_dump(gpu);
>>       etnaviv_gpu_recover_hang(gpu);
>>   +    drm_sched_resubmit_jobs(&gpu->sched);
>> +
>>       /* restart scheduler after GPU is usable again */
>> -    drm_sched_job_recovery(&gpu->sched);
>> -    kthread_unpark(gpu->sched.thread);
>> +    drm_sched_start(&gpu->sched, true);
>>   }
>>     static void etnaviv_sched_free_job(struct drm_sched_job *sched_job)
>> diff --git a/drivers/gpu/drm/scheduler/sched_main.c 
>> b/drivers/gpu/drm/scheduler/sched_main.c
>> index dbb6906..1cf9541 100644
>> --- a/drivers/gpu/drm/scheduler/sched_main.c
>> +++ b/drivers/gpu/drm/scheduler/sched_main.c
>> @@ -60,8 +60,6 @@
>>     static void drm_sched_process_job(struct dma_fence *f, struct 
>> dma_fence_cb *cb);
>>   -static void drm_sched_expel_job_unlocked(struct drm_sched_job 
>> *s_job);
>> -
>>   /**
>>    * drm_sched_rq_init - initialize a given run queue struct
>>    *
>> @@ -335,6 +333,41 @@ static void drm_sched_job_timedout(struct 
>> work_struct *work)
>>       spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>   }
>>   +static void drm_sched_increase_karma(struct drm_sched_job *bad)
>> +{
>> +    int i;
>> +    struct drm_sched_entity *tmp;
>> +    struct drm_sched_entity *entity;
>> +    struct drm_gpu_scheduler *sched = bad->sched;
>> +
>> +    /* don't increase @bad's karma if it's from KERNEL RQ,
>> +     * because sometimes GPU hang would cause kernel jobs (like VM 
>> updating jobs)
>> +     * corrupt but keep in mind that kernel jobs always considered 
>> good.
>> +     */
>> +    if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
>> +        atomic_inc(&bad->karma);
>> +        for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL;
>> +             i++) {
>> +            struct drm_sched_rq *rq = &sched->sched_rq[i];
>> +
>> +            spin_lock(&rq->lock);
>> +            list_for_each_entry_safe(entity, tmp, &rq->entities, 
>> list) {
>> +                if (bad->s_fence->scheduled.context ==
>> +                    entity->fence_context) {
>> +                    if (atomic_read(&bad->karma) >
>> +                        bad->sched->hang_limit)
>> +                        if (entity->guilty)
>> +                            atomic_set(entity->guilty, 1);
>> +                    break;
>> +                }
>> +            }
>> +            spin_unlock(&rq->lock);
>> +            if (&entity->list != &rq->entities)
>> +                break;
>> +        }
>> +    }
>> +}
>> +
>>   /**
>>    * drm_sched_hw_job_reset - stop the scheduler if it contains the 
>> bad job
>>    *
>> @@ -342,12 +375,15 @@ static void drm_sched_job_timedout(struct 
>> work_struct *work)
>>    * @bad: bad scheduler job
>>    *
>>    */
>> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct 
>> drm_sched_job *bad)
>> +void drm_sched_stop(struct drm_gpu_scheduler *sched, struct 
>> drm_sched_job *bad)
>>   {
>>       struct drm_sched_job *s_job;
>> -    struct drm_sched_entity *entity, *tmp;
>>       unsigned long flags;
>> -    int i;
>> +    struct list_head wait_list;
>> +
>> +    kthread_park(sched->thread);
>> +
>> +    INIT_LIST_HEAD(&wait_list);
>>         spin_lock_irqsave(&sched->job_list_lock, flags);
>>       list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, 
>> node) {
>> @@ -357,35 +393,28 @@ void drm_sched_hw_job_reset(struct 
>> drm_gpu_scheduler *sched, struct drm_sched_jo
>>               dma_fence_put(s_job->s_fence->parent);
>>               s_job->s_fence->parent = NULL;
>>               atomic_dec(&sched->hw_rq_count);
>> +        } else {
>> +            /* TODO Is it get/put neccessey here ? */
>> +            dma_fence_get(&s_job->s_fence->finished);
>> +            list_add(&s_job->finish_node, &wait_list);
>>           }
>>       }
>>       spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>   -    if (bad && bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
>> -        atomic_inc(&bad->karma);
>> -        /* don't increase @bad's karma if it's from KERNEL RQ,
>> -         * becuase sometimes GPU hang would cause kernel jobs (like 
>> VM updating jobs)
>> -         * corrupt but keep in mind that kernel jobs always 
>> considered good.
>> -         */
>> -        for (i = DRM_SCHED_PRIORITY_MIN; i < 
>> DRM_SCHED_PRIORITY_KERNEL; i++ ) {
>> -            struct drm_sched_rq *rq = &sched->sched_rq[i];
>> -
>> -            spin_lock(&rq->lock);
>> -            list_for_each_entry_safe(entity, tmp, &rq->entities, 
>> list) {
>> -                if (bad->s_fence->scheduled.context == 
>> entity->fence_context) {
>> -                    if (atomic_read(&bad->karma) > 
>> bad->sched->hang_limit)
>> -                        if (entity->guilty)
>> -                            atomic_set(entity->guilty, 1);
>> -                    break;
>> -                }
>> -            }
>> -            spin_unlock(&rq->lock);
>> -            if (&entity->list != &rq->entities)
>> -                break;
>> -        }
>> +    /*
>> +     * Verify all the signaled jobs in mirror list are removed from 
>> the ring
>> +     * We rely on the fact that any finish_work in progress will 
>> wait for this
>> +     * handler to complete before releasing all of the jobs we iterate.
>> +     */
>> +    list_for_each_entry(s_job, &wait_list, finish_node) {
>> +        dma_fence_wait(&s_job->s_fence->finished, false);
>> +        dma_fence_put(&s_job->s_fence->finished);
>>       }
>
> Mhm, thinking more about it that approach won't work.
>
> Only the scheduler instance with the timeout will block on the GPU 
> reset to finish before freeing up s_job.
>
> The job_list_lock will protect us, but as soon as that is dropped we 
> are potentially working with freed up jobs here.
>
> Maybe your idea of just waiting for the last finished fence to signal 
> wasn't so bad after all. This way you only need to grab the last one 
> and wait for it.

I was concerned with relying on the assumption saying that  if last job 
(it's fence actually) in ring_mirror_list  is signaled then necessary 
all the previous jobs/fences in the list have already signaled   - does 
the order of submission into HW ring (same as order of insertion into 
ring_mirror_list ) implies necessary same order of job/fence completion 
? I know we talked about it already but I still not sure, is this 
ALWAYS  true ?

What about instead of using the jobs as elements for the wait_list we 
can just locally here dynamically allocate some
struct fence_cont {
     struct list_head  node;
     struct dma_fence        *finished;
}
and then we can iterate that list and wait for the fence to signal 
without worrying for the jobs being already released ?

Andrey

>
> And since fences are reference counted we also don't run into any 
> problems because of that.
>
>> +
>> +    if (bad)
>> +        drm_sched_increase_karma(bad);
>
> Better export drm_sched_increase_karma() and let the drivers call that 
> implicitly.
>
> Regards,
> Christian.
>
>>   }
>> -EXPORT_SYMBOL(drm_sched_hw_job_reset);
>> +EXPORT_SYMBOL(drm_sched_stop);
>>     /**
>>    * drm_sched_job_recovery - recover jobs after a reset
>> @@ -393,33 +422,21 @@ EXPORT_SYMBOL(drm_sched_hw_job_reset);
>>    * @sched: scheduler instance
>>    *
>>    */
>> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
>> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool 
>> full_recovery)
>>   {
>>       struct drm_sched_job *s_job, *tmp;
>> -    bool found_guilty = false;
>>       unsigned long flags;
>>       int r;
>>   +    if (!full_recovery)
>> +        goto unpark;
>> +
>>       spin_lock_irqsave(&sched->job_list_lock, flags);
>>       list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, 
>> node) {
>>           struct drm_sched_fence *s_fence = s_job->s_fence;
>> -        struct dma_fence *fence;
>> -        uint64_t guilty_context;
>> -
>> -        if (!found_guilty && atomic_read(&s_job->karma) > 
>> sched->hang_limit) {
>> -            found_guilty = true;
>> -            guilty_context = s_job->s_fence->scheduled.context;
>> -        }
>> -
>> -        if (found_guilty && s_job->s_fence->scheduled.context == 
>> guilty_context)
>> -            dma_fence_set_error(&s_fence->finished, -ECANCELED);
>> -
>> -        spin_unlock_irqrestore(&sched->job_list_lock, flags);
>> -        fence = sched->ops->run_job(s_job);
>> -        atomic_inc(&sched->hw_rq_count);
>> +        struct dma_fence *fence = s_job->s_fence->parent;
>>             if (fence) {
>> -            s_fence->parent = dma_fence_get(fence);
>>               r = dma_fence_add_callback(fence, &s_fence->cb,
>>                              drm_sched_process_job);
>>               if (r == -ENOENT)
>> @@ -427,18 +444,47 @@ void drm_sched_job_recovery(struct 
>> drm_gpu_scheduler *sched)
>>               else if (r)
>>                   DRM_ERROR("fence add callback failed (%d)\n",
>>                         r);
>> -            dma_fence_put(fence);
>> -        } else {
>> -            if (s_fence->finished.error < 0)
>> -                drm_sched_expel_job_unlocked(s_job);
>> +        } else
>>               drm_sched_process_job(NULL, &s_fence->cb);
>> -        }
>> -        spin_lock_irqsave(&sched->job_list_lock, flags);
>>       }
>> +
>>       drm_sched_start_timeout(sched);
>>       spin_unlock_irqrestore(&sched->job_list_lock, flags);
>> +
>> +unpark:
>> +    kthread_unpark(sched->thread);
>>   }
>> -EXPORT_SYMBOL(drm_sched_job_recovery);
>> +EXPORT_SYMBOL(drm_sched_start);
>> +
>> +/**
>> + * drm_sched_resubmit_jobs - helper to relunch job from mirror ring 
>> list
>> + *
>> + * @sched: scheduler instance
>> + *
>> + */
>> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched)
>> +{
>> +    struct drm_sched_job *s_job, *tmp;
>> +    uint64_t guilty_context;
>> +    bool found_guilty = false;
>> +
>> +    /*TODO DO we need spinlock here ? */
>> +    list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, 
>> node) {
>> +        struct drm_sched_fence *s_fence = s_job->s_fence;
>> +
>> +        if (!found_guilty && atomic_read(&s_job->karma) > 
>> sched->hang_limit) {
>> +            found_guilty = true;
>> +            guilty_context = s_job->s_fence->scheduled.context;
>> +        }
>> +
>> +        if (found_guilty && s_job->s_fence->scheduled.context == 
>> guilty_context)
>> +            dma_fence_set_error(&s_fence->finished, -ECANCELED);
>> +
>> +        s_job->s_fence->parent = sched->ops->run_job(s_job);
>> +        atomic_inc(&sched->hw_rq_count);
>> +    }
>> +}
>> +EXPORT_SYMBOL(drm_sched_resubmit_jobs);
>>     /**
>>    * drm_sched_job_init - init a scheduler job
>> @@ -634,26 +680,14 @@ static int drm_sched_main(void *param)
>>                   DRM_ERROR("fence add callback failed (%d)\n",
>>                         r);
>>               dma_fence_put(fence);
>> -        } else {
>> -            if (s_fence->finished.error < 0)
>> -                drm_sched_expel_job_unlocked(sched_job);
>> +        } else
>>               drm_sched_process_job(NULL, &s_fence->cb);
>> -        }
>>             wake_up(&sched->job_scheduled);
>>       }
>>       return 0;
>>   }
>>   -static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job)
>> -{
>> -    struct drm_gpu_scheduler *sched = s_job->sched;
>> -
>> -    spin_lock(&sched->job_list_lock);
>> -    list_del_init(&s_job->node);
>> -    spin_unlock(&sched->job_list_lock);
>> -}
>> -
>>   /**
>>    * drm_sched_init - Init a gpu scheduler instance
>>    *
>> diff --git a/drivers/gpu/drm/v3d/v3d_sched.c 
>> b/drivers/gpu/drm/v3d/v3d_sched.c
>> index 445b2ef..aaa10b0 100644
>> --- a/drivers/gpu/drm/v3d/v3d_sched.c
>> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
>> @@ -178,18 +178,19 @@ v3d_job_timedout(struct drm_sched_job *sched_job)
>>       for (q = 0; q < V3D_MAX_QUEUES; q++) {
>>           struct drm_gpu_scheduler *sched = &v3d->queue[q].sched;
>>   -        kthread_park(sched->thread);
>> -        drm_sched_hw_job_reset(sched, (sched_job->sched == sched ?
>> +        drm_sched_stop(sched, (sched_job->sched == sched ?
>>                              sched_job : NULL));
>>       }
>>         /* get the GPU back into the init state */
>>       v3d_reset(v3d);
>>   +    for (q = 0; q < V3D_MAX_QUEUES; q++)
>> +        drm_sched_resubmit_jobs(sched_job->sched);
>> +
>>       /* Unblock schedulers and restart their jobs. */
>>       for (q = 0; q < V3D_MAX_QUEUES; q++) {
>> -        drm_sched_job_recovery(&v3d->queue[q].sched);
>> -        kthread_unpark(v3d->queue[q].sched.thread);
>> +        drm_sched_start(&v3d->queue[q].sched, true);
>>       }
>>         mutex_unlock(&v3d->reset_lock);
>> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
>> index 47e1979..441384c 100644
>> --- a/include/drm/gpu_scheduler.h
>> +++ b/include/drm/gpu_scheduler.h
>> @@ -175,6 +175,7 @@ struct drm_sched_fence *to_drm_sched_fence(struct 
>> dma_fence *f);
>>    *               finished to remove the job from the
>>    *               @drm_gpu_scheduler.ring_mirror_list.
>>    * @node: used to append this struct to the 
>> @drm_gpu_scheduler.ring_mirror_list.
>> + * @finish_node: used in a list to wait on before resetting the 
>> scheduler
>>    * @id: a unique id assigned to each job scheduled on the scheduler.
>>    * @karma: increment on every hang caused by this job. If this 
>> exceeds the hang
>>    *         limit of the scheduler then the job is marked guilty and 
>> will not
>> @@ -193,6 +194,7 @@ struct drm_sched_job {
>>       struct dma_fence_cb        finish_cb;
>>       struct work_struct        finish_work;
>>       struct list_head        node;
>> +    struct list_head        finish_node;
>>       uint64_t            id;
>>       atomic_t            karma;
>>       enum drm_sched_priority        s_priority;
>> @@ -298,9 +300,10 @@ int drm_sched_job_init(struct drm_sched_job *job,
>>                  void *owner);
>>   void drm_sched_job_cleanup(struct drm_sched_job *job);
>>   void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
>> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched,
>> -                struct drm_sched_job *job);
>> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched);
>> +void drm_sched_stop(struct drm_gpu_scheduler *sched,
>> +            struct drm_sched_job *job);
>> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool 
>> full_recovery);
>> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
>>   bool drm_sched_dependency_optimized(struct dma_fence* fence,
>>                       struct drm_sched_entity *entity);
>>   void drm_sched_fault(struct drm_gpu_scheduler *sched);
>
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Re: [PATCH v4 1/2] drm/sched: Refactor ring mirror list handling.

[Koenig, Christian]

Am 19.12.18 um 18:32 schrieb Grodzovsky, Andrey:
>
> On 12/19/2018 11:21 AM, Christian König wrote:
>> Am 17.12.18 um 20:51 schrieb Andrey Grodzovsky:
>>> Decauple sched threads stop and start and ring mirror
>>> list handling from the policy of what to do about the
>>> guilty jobs.
>>> When stoppping the sched thread and detaching sched fences
>>> from non signaled HW fenes wait for all signaled HW fences
>>> to complete before rerunning the jobs.
>>>
>>> v2: Fix resubmission of guilty job into HW after refactoring.
>>>
>>> v4:
>>> Full restart for all the jobs, not only from guilty ring.
>>> Extract karma increase into standalone function.
>>>
>>> Suggested-by: Christian Koenig <Christian.Koenig@amd.com>
>>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
>>> ---
>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  17 +--
>>>    drivers/gpu/drm/etnaviv/etnaviv_sched.c    |   8 +-
>>>    drivers/gpu/drm/scheduler/sched_main.c     | 164
>>> +++++++++++++++++------------
>>>    drivers/gpu/drm/v3d/v3d_sched.c            |   9 +-
>>>    include/drm/gpu_scheduler.h                |   9 +-
>>>    5 files changed, 118 insertions(+), 89 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> index 8a078f4..8ac4f43 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -3298,12 +3298,7 @@ static int amdgpu_device_pre_asic_reset(struct
>>> amdgpu_device *adev,
>>>            if (!ring || !ring->sched.thread)
>>>                continue;
>>>    -        kthread_park(ring->sched.thread);
>>> -
>>> -        if (job && job->base.sched != &ring->sched)
>>> -            continue;
>>> -
>>> -        drm_sched_hw_job_reset(&ring->sched, job ? &job->base : NULL);
>>> +        drm_sched_stop(&ring->sched, job ? &job->base : NULL);
>>>              /* after all hw jobs are reset, hw fence is meaningless,
>>> so force_completion */
>>>            amdgpu_fence_driver_force_completion(ring);
>>> @@ -3454,14 +3449,10 @@ static void
>>> amdgpu_device_post_asic_reset(struct amdgpu_device *adev,
>>>            if (!ring || !ring->sched.thread)
>>>                continue;
>>>    -        /* only need recovery sched of the given job's ring
>>> -         * or all rings (in the case @job is NULL)
>>> -         * after above amdgpu_reset accomplished
>>> -         */
>>> -        if ((!job || job->base.sched == &ring->sched) &&
>>> !adev->asic_reset_res)
>>> -            drm_sched_job_recovery(&ring->sched);
>>> +        if (!adev->asic_reset_res)
>>> +            drm_sched_resubmit_jobs(&ring->sched);
>>>    -        kthread_unpark(ring->sched.thread);
>>> +        drm_sched_start(&ring->sched, !adev->asic_reset_res);
>>>        }
>>>          if (!amdgpu_device_has_dc_support(adev)) {
>>> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> index 49a6763..d7075cd 100644
>>> --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> @@ -109,16 +109,16 @@ static void etnaviv_sched_timedout_job(struct
>>> drm_sched_job *sched_job)
>>>        }
>>>          /* block scheduler */
>>> -    kthread_park(gpu->sched.thread);
>>> -    drm_sched_hw_job_reset(&gpu->sched, sched_job);
>>> +    drm_sched_stop(&gpu->sched, sched_job);
>>>          /* get the GPU back into the init state */
>>>        etnaviv_core_dump(gpu);
>>>        etnaviv_gpu_recover_hang(gpu);
>>>    +    drm_sched_resubmit_jobs(&gpu->sched);
>>> +
>>>        /* restart scheduler after GPU is usable again */
>>> -    drm_sched_job_recovery(&gpu->sched);
>>> -    kthread_unpark(gpu->sched.thread);
>>> +    drm_sched_start(&gpu->sched, true);
>>>    }
>>>      static void etnaviv_sched_free_job(struct drm_sched_job *sched_job)
>>> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
>>> b/drivers/gpu/drm/scheduler/sched_main.c
>>> index dbb6906..1cf9541 100644
>>> --- a/drivers/gpu/drm/scheduler/sched_main.c
>>> +++ b/drivers/gpu/drm/scheduler/sched_main.c
>>> @@ -60,8 +60,6 @@
>>>      static void drm_sched_process_job(struct dma_fence *f, struct
>>> dma_fence_cb *cb);
>>>    -static void drm_sched_expel_job_unlocked(struct drm_sched_job
>>> *s_job);
>>> -
>>>    /**
>>>     * drm_sched_rq_init - initialize a given run queue struct
>>>     *
>>> @@ -335,6 +333,41 @@ static void drm_sched_job_timedout(struct
>>> work_struct *work)
>>>        spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>>    }
>>>    +static void drm_sched_increase_karma(struct drm_sched_job *bad)
>>> +{
>>> +    int i;
>>> +    struct drm_sched_entity *tmp;
>>> +    struct drm_sched_entity *entity;
>>> +    struct drm_gpu_scheduler *sched = bad->sched;
>>> +
>>> +    /* don't increase @bad's karma if it's from KERNEL RQ,
>>> +     * because sometimes GPU hang would cause kernel jobs (like VM
>>> updating jobs)
>>> +     * corrupt but keep in mind that kernel jobs always considered
>>> good.
>>> +     */
>>> +    if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
>>> +        atomic_inc(&bad->karma);
>>> +        for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL;
>>> +             i++) {
>>> +            struct drm_sched_rq *rq = &sched->sched_rq[i];
>>> +
>>> +            spin_lock(&rq->lock);
>>> +            list_for_each_entry_safe(entity, tmp, &rq->entities,
>>> list) {
>>> +                if (bad->s_fence->scheduled.context ==
>>> +                    entity->fence_context) {
>>> +                    if (atomic_read(&bad->karma) >
>>> +                        bad->sched->hang_limit)
>>> +                        if (entity->guilty)
>>> +                            atomic_set(entity->guilty, 1);
>>> +                    break;
>>> +                }
>>> +            }
>>> +            spin_unlock(&rq->lock);
>>> +            if (&entity->list != &rq->entities)
>>> +                break;
>>> +        }
>>> +    }
>>> +}
>>> +
>>>    /**
>>>     * drm_sched_hw_job_reset - stop the scheduler if it contains the
>>> bad job
>>>     *
>>> @@ -342,12 +375,15 @@ static void drm_sched_job_timedout(struct
>>> work_struct *work)
>>>     * @bad: bad scheduler job
>>>     *
>>>     */
>>> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct
>>> drm_sched_job *bad)
>>> +void drm_sched_stop(struct drm_gpu_scheduler *sched, struct
>>> drm_sched_job *bad)
>>>    {
>>>        struct drm_sched_job *s_job;
>>> -    struct drm_sched_entity *entity, *tmp;
>>>        unsigned long flags;
>>> -    int i;
>>> +    struct list_head wait_list;
>>> +
>>> +    kthread_park(sched->thread);
>>> +
>>> +    INIT_LIST_HEAD(&wait_list);
>>>          spin_lock_irqsave(&sched->job_list_lock, flags);
>>>        list_for_each_entry_reverse(s_job, &sched->ring_mirror_list,
>>> node) {
>>> @@ -357,35 +393,28 @@ void drm_sched_hw_job_reset(struct
>>> drm_gpu_scheduler *sched, struct drm_sched_jo
>>>                dma_fence_put(s_job->s_fence->parent);
>>>                s_job->s_fence->parent = NULL;
>>>                atomic_dec(&sched->hw_rq_count);
>>> +        } else {
>>> +            /* TODO Is it get/put neccessey here ? */
>>> +            dma_fence_get(&s_job->s_fence->finished);
>>> +            list_add(&s_job->finish_node, &wait_list);
>>>            }
>>>        }
>>>        spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>>    -    if (bad && bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
>>> -        atomic_inc(&bad->karma);
>>> -        /* don't increase @bad's karma if it's from KERNEL RQ,
>>> -         * becuase sometimes GPU hang would cause kernel jobs (like
>>> VM updating jobs)
>>> -         * corrupt but keep in mind that kernel jobs always
>>> considered good.
>>> -         */
>>> -        for (i = DRM_SCHED_PRIORITY_MIN; i <
>>> DRM_SCHED_PRIORITY_KERNEL; i++ ) {
>>> -            struct drm_sched_rq *rq = &sched->sched_rq[i];
>>> -
>>> -            spin_lock(&rq->lock);
>>> -            list_for_each_entry_safe(entity, tmp, &rq->entities,
>>> list) {
>>> -                if (bad->s_fence->scheduled.context ==
>>> entity->fence_context) {
>>> -                    if (atomic_read(&bad->karma) >
>>> bad->sched->hang_limit)
>>> -                        if (entity->guilty)
>>> -                            atomic_set(entity->guilty, 1);
>>> -                    break;
>>> -                }
>>> -            }
>>> -            spin_unlock(&rq->lock);
>>> -            if (&entity->list != &rq->entities)
>>> -                break;
>>> -        }
>>> +    /*
>>> +     * Verify all the signaled jobs in mirror list are removed from
>>> the ring
>>> +     * We rely on the fact that any finish_work in progress will
>>> wait for this
>>> +     * handler to complete before releasing all of the jobs we iterate.
>>> +     */
>>> +    list_for_each_entry(s_job, &wait_list, finish_node) {
>>> +        dma_fence_wait(&s_job->s_fence->finished, false);
>>> +        dma_fence_put(&s_job->s_fence->finished);
>>>        }
>> Mhm, thinking more about it that approach won't work.
>>
>> Only the scheduler instance with the timeout will block on the GPU
>> reset to finish before freeing up s_job.
>>
>> The job_list_lock will protect us, but as soon as that is dropped we
>> are potentially working with freed up jobs here.
>>
>> Maybe your idea of just waiting for the last finished fence to signal
>> wasn't so bad after all. This way you only need to grab the last one
>> and wait for it.
> I was concerned with relying on the assumption saying that  if last job
> (it's fence actually) in ring_mirror_list  is signaled then necessary
> all the previous jobs/fences in the list have already signaled   - does
> the order of submission into HW ring (same as order of insertion into
> ring_mirror_list ) implies necessary same order of job/fence completion
> ? I know we talked about it already but I still not sure, is this
> ALWAYS  true ?

Well it is always true that the hw fence signals in order.

The problem here is that I'm not 100% sure if that's also true for the 
scheduler fence.

E.g. when we signal the scheduler fence from the callback (like we 
should), then it should not be a problem.

> What about instead of using the jobs as elements for the wait_list we
> can just locally here dynamically allocate some
> struct fence_cont {
>       struct list_head  node;
>       struct dma_fence        *finished;
> }
> and then we can iterate that list and wait for the fence to signal
> without worrying for the jobs being already released ?

If we can't signal the scheduler fence from the hw fence callback I 
would rather say do a multi step approach.

E.g. walk over the list of jobs and remove the callbacks.

If you find a job which is already signaled you remember the fence, 
abort and add the callbacks again.

Drop the lock, wait for the fence and then try again to remove the 
callbacks.

Christian.

>
> Andrey
>
>> And since fences are reference counted we also don't run into any
>> problems because of that.
>>
>>> +
>>> +    if (bad)
>>> +        drm_sched_increase_karma(bad);
>> Better export drm_sched_increase_karma() and let the drivers call that
>> implicitly.
>>
>> Regards,
>> Christian.
>>
>>>    }
>>> -EXPORT_SYMBOL(drm_sched_hw_job_reset);
>>> +EXPORT_SYMBOL(drm_sched_stop);
>>>      /**
>>>     * drm_sched_job_recovery - recover jobs after a reset
>>> @@ -393,33 +422,21 @@ EXPORT_SYMBOL(drm_sched_hw_job_reset);
>>>     * @sched: scheduler instance
>>>     *
>>>     */
>>> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
>>> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool
>>> full_recovery)
>>>    {
>>>        struct drm_sched_job *s_job, *tmp;
>>> -    bool found_guilty = false;
>>>        unsigned long flags;
>>>        int r;
>>>    +    if (!full_recovery)
>>> +        goto unpark;
>>> +
>>>        spin_lock_irqsave(&sched->job_list_lock, flags);
>>>        list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list,
>>> node) {
>>>            struct drm_sched_fence *s_fence = s_job->s_fence;
>>> -        struct dma_fence *fence;
>>> -        uint64_t guilty_context;
>>> -
>>> -        if (!found_guilty && atomic_read(&s_job->karma) >
>>> sched->hang_limit) {
>>> -            found_guilty = true;
>>> -            guilty_context = s_job->s_fence->scheduled.context;
>>> -        }
>>> -
>>> -        if (found_guilty && s_job->s_fence->scheduled.context ==
>>> guilty_context)
>>> -            dma_fence_set_error(&s_fence->finished, -ECANCELED);
>>> -
>>> -        spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> -        fence = sched->ops->run_job(s_job);
>>> -        atomic_inc(&sched->hw_rq_count);
>>> +        struct dma_fence *fence = s_job->s_fence->parent;
>>>              if (fence) {
>>> -            s_fence->parent = dma_fence_get(fence);
>>>                r = dma_fence_add_callback(fence, &s_fence->cb,
>>>                               drm_sched_process_job);
>>>                if (r == -ENOENT)
>>> @@ -427,18 +444,47 @@ void drm_sched_job_recovery(struct
>>> drm_gpu_scheduler *sched)
>>>                else if (r)
>>>                    DRM_ERROR("fence add callback failed (%d)\n",
>>>                          r);
>>> -            dma_fence_put(fence);
>>> -        } else {
>>> -            if (s_fence->finished.error < 0)
>>> -                drm_sched_expel_job_unlocked(s_job);
>>> +        } else
>>>                drm_sched_process_job(NULL, &s_fence->cb);
>>> -        }
>>> -        spin_lock_irqsave(&sched->job_list_lock, flags);
>>>        }
>>> +
>>>        drm_sched_start_timeout(sched);
>>>        spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> +
>>> +unpark:
>>> +    kthread_unpark(sched->thread);
>>>    }
>>> -EXPORT_SYMBOL(drm_sched_job_recovery);
>>> +EXPORT_SYMBOL(drm_sched_start);
>>> +
>>> +/**
>>> + * drm_sched_resubmit_jobs - helper to relunch job from mirror ring
>>> list
>>> + *
>>> + * @sched: scheduler instance
>>> + *
>>> + */
>>> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched)
>>> +{
>>> +    struct drm_sched_job *s_job, *tmp;
>>> +    uint64_t guilty_context;
>>> +    bool found_guilty = false;
>>> +
>>> +    /*TODO DO we need spinlock here ? */
>>> +    list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list,
>>> node) {
>>> +        struct drm_sched_fence *s_fence = s_job->s_fence;
>>> +
>>> +        if (!found_guilty && atomic_read(&s_job->karma) >
>>> sched->hang_limit) {
>>> +            found_guilty = true;
>>> +            guilty_context = s_job->s_fence->scheduled.context;
>>> +        }
>>> +
>>> +        if (found_guilty && s_job->s_fence->scheduled.context ==
>>> guilty_context)
>>> +            dma_fence_set_error(&s_fence->finished, -ECANCELED);
>>> +
>>> +        s_job->s_fence->parent = sched->ops->run_job(s_job);
>>> +        atomic_inc(&sched->hw_rq_count);
>>> +    }
>>> +}
>>> +EXPORT_SYMBOL(drm_sched_resubmit_jobs);
>>>      /**
>>>     * drm_sched_job_init - init a scheduler job
>>> @@ -634,26 +680,14 @@ static int drm_sched_main(void *param)
>>>                    DRM_ERROR("fence add callback failed (%d)\n",
>>>                          r);
>>>                dma_fence_put(fence);
>>> -        } else {
>>> -            if (s_fence->finished.error < 0)
>>> -                drm_sched_expel_job_unlocked(sched_job);
>>> +        } else
>>>                drm_sched_process_job(NULL, &s_fence->cb);
>>> -        }
>>>              wake_up(&sched->job_scheduled);
>>>        }
>>>        return 0;
>>>    }
>>>    -static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job)
>>> -{
>>> -    struct drm_gpu_scheduler *sched = s_job->sched;
>>> -
>>> -    spin_lock(&sched->job_list_lock);
>>> -    list_del_init(&s_job->node);
>>> -    spin_unlock(&sched->job_list_lock);
>>> -}
>>> -
>>>    /**
>>>     * drm_sched_init - Init a gpu scheduler instance
>>>     *
>>> diff --git a/drivers/gpu/drm/v3d/v3d_sched.c
>>> b/drivers/gpu/drm/v3d/v3d_sched.c
>>> index 445b2ef..aaa10b0 100644
>>> --- a/drivers/gpu/drm/v3d/v3d_sched.c
>>> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
>>> @@ -178,18 +178,19 @@ v3d_job_timedout(struct drm_sched_job *sched_job)
>>>        for (q = 0; q < V3D_MAX_QUEUES; q++) {
>>>            struct drm_gpu_scheduler *sched = &v3d->queue[q].sched;
>>>    -        kthread_park(sched->thread);
>>> -        drm_sched_hw_job_reset(sched, (sched_job->sched == sched ?
>>> +        drm_sched_stop(sched, (sched_job->sched == sched ?
>>>                               sched_job : NULL));
>>>        }
>>>          /* get the GPU back into the init state */
>>>        v3d_reset(v3d);
>>>    +    for (q = 0; q < V3D_MAX_QUEUES; q++)
>>> +        drm_sched_resubmit_jobs(sched_job->sched);
>>> +
>>>        /* Unblock schedulers and restart their jobs. */
>>>        for (q = 0; q < V3D_MAX_QUEUES; q++) {
>>> -        drm_sched_job_recovery(&v3d->queue[q].sched);
>>> -        kthread_unpark(v3d->queue[q].sched.thread);
>>> +        drm_sched_start(&v3d->queue[q].sched, true);
>>>        }
>>>          mutex_unlock(&v3d->reset_lock);
>>> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
>>> index 47e1979..441384c 100644
>>> --- a/include/drm/gpu_scheduler.h
>>> +++ b/include/drm/gpu_scheduler.h
>>> @@ -175,6 +175,7 @@ struct drm_sched_fence *to_drm_sched_fence(struct
>>> dma_fence *f);
>>>     *               finished to remove the job from the
>>>     *               @drm_gpu_scheduler.ring_mirror_list.
>>>     * @node: used to append this struct to the
>>> @drm_gpu_scheduler.ring_mirror_list.
>>> + * @finish_node: used in a list to wait on before resetting the
>>> scheduler
>>>     * @id: a unique id assigned to each job scheduled on the scheduler.
>>>     * @karma: increment on every hang caused by this job. If this
>>> exceeds the hang
>>>     *         limit of the scheduler then the job is marked guilty and
>>> will not
>>> @@ -193,6 +194,7 @@ struct drm_sched_job {
>>>        struct dma_fence_cb        finish_cb;
>>>        struct work_struct        finish_work;
>>>        struct list_head        node;
>>> +    struct list_head        finish_node;
>>>        uint64_t            id;
>>>        atomic_t            karma;
>>>        enum drm_sched_priority        s_priority;
>>> @@ -298,9 +300,10 @@ int drm_sched_job_init(struct drm_sched_job *job,
>>>                   void *owner);
>>>    void drm_sched_job_cleanup(struct drm_sched_job *job);
>>>    void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
>>> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched,
>>> -                struct drm_sched_job *job);
>>> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched);
>>> +void drm_sched_stop(struct drm_gpu_scheduler *sched,
>>> +            struct drm_sched_job *job);
>>> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool
>>> full_recovery);
>>> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
>>>    bool drm_sched_dependency_optimized(struct dma_fence* fence,
>>>                        struct drm_sched_entity *entity);
>>>    void drm_sched_fault(struct drm_gpu_scheduler *sched);
>> _______________________________________________
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>> amd-gfx@lists.freedesktop.org
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