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* [PATCH v5] drm: Don't free jobs in wait_event_interruptible()
@ 2019-10-25 10:51 ` Steven Price
  0 siblings, 0 replies; 4+ messages in thread
From: Steven Price @ 2019-10-25 10:51 UTC (permalink / raw)
  To: Daniel Vetter, David Airlie
  Cc: dri-devel, linux-kernel, Christian König, Alex Deucher,
	Andrey Grodzovsky, Erico Nunes, Sam Ravnborg, Sharat Masetty,
	Steven Price, Christian Gmeiner

drm_sched_cleanup_jobs() attempts to free finished jobs, however because
it is called as the condition of wait_event_interruptible() it must not
sleep. Unfortunately some free callbacks (notably for Panfrost) do sleep.

Instead let's rename drm_sched_cleanup_jobs() to
drm_sched_get_cleanup_job() and simply return a job for processing if
there is one. The caller can then call the free_job() callback outside
the wait_event_interruptible() where sleeping is possible before
re-checking and returning to sleep if necessary.

Tested-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Fixes: 5918045c4ed4 ("drm/scheduler: rework job destruction")
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v4:
 * Don't initialise job in drm_sched_get_cleanup_job()
 * Change while loop into if in drm_sched_main()

 drivers/gpu/drm/scheduler/sched_main.c | 43 ++++++++++++++------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 9a0ee74d82dc..d4cc7289147e 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -622,43 +622,41 @@ static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb)
 }
 
 /**
- * drm_sched_cleanup_jobs - destroy finished jobs
+ * drm_sched_get_cleanup_job - fetch the next finished job to be destroyed
  *
  * @sched: scheduler instance
  *
- * Remove all finished jobs from the mirror list and destroy them.
+ * Returns the next finished job from the mirror list (if there is one)
+ * ready for it to be destroyed.
  */
-static void drm_sched_cleanup_jobs(struct drm_gpu_scheduler *sched)
+static struct drm_sched_job *
+drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)
 {
+	struct drm_sched_job *job;
 	unsigned long flags;
 
 	/* Don't destroy jobs while the timeout worker is running */
 	if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
 	    !cancel_delayed_work(&sched->work_tdr))
-		return;
-
+		return NULL;
 
-	while (!list_empty(&sched->ring_mirror_list)) {
-		struct drm_sched_job *job;
+	spin_lock_irqsave(&sched->job_list_lock, flags);
 
-		job = list_first_entry(&sched->ring_mirror_list,
+	job = list_first_entry_or_null(&sched->ring_mirror_list,
 				       struct drm_sched_job, node);
-		if (!dma_fence_is_signaled(&job->s_fence->finished))
-			break;
 
-		spin_lock_irqsave(&sched->job_list_lock, flags);
+	if (job && dma_fence_is_signaled(&job->s_fence->finished)) {
 		/* remove job from ring_mirror_list */
 		list_del_init(&job->node);
-		spin_unlock_irqrestore(&sched->job_list_lock, flags);
-
-		sched->ops->free_job(job);
+	} else {
+		job = NULL;
+		/* queue timeout for next job */
+		drm_sched_start_timeout(sched);
 	}
 
-	/* queue timeout for next job */
-	spin_lock_irqsave(&sched->job_list_lock, flags);
-	drm_sched_start_timeout(sched);
 	spin_unlock_irqrestore(&sched->job_list_lock, flags);
 
+	return job;
 }
 
 /**
@@ -698,12 +696,19 @@ static int drm_sched_main(void *param)
 		struct drm_sched_fence *s_fence;
 		struct drm_sched_job *sched_job;
 		struct dma_fence *fence;
+		struct drm_sched_job *cleanup_job = NULL;
 
 		wait_event_interruptible(sched->wake_up_worker,
-					 (drm_sched_cleanup_jobs(sched),
+					 (cleanup_job = drm_sched_get_cleanup_job(sched)) ||
 					 (!drm_sched_blocked(sched) &&
 					  (entity = drm_sched_select_entity(sched))) ||
-					 kthread_should_stop()));
+					 kthread_should_stop());
+
+		if (cleanup_job) {
+			sched->ops->free_job(cleanup_job);
+			/* queue timeout for next job */
+			drm_sched_start_timeout(sched);
+		}
 
 		if (!entity)
 			continue;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH v5] drm: Don't free jobs in wait_event_interruptible()
@ 2019-10-25 10:51 ` Steven Price
  0 siblings, 0 replies; 4+ messages in thread
From: Steven Price @ 2019-10-25 10:51 UTC (permalink / raw)
  To: Daniel Vetter, David Airlie
  Cc: Sharat Masetty, linux-kernel, dri-devel, Steven Price,
	Alex Deucher, Sam Ravnborg, Christian König, Erico Nunes

drm_sched_cleanup_jobs() attempts to free finished jobs, however because
it is called as the condition of wait_event_interruptible() it must not
sleep. Unfortunately some free callbacks (notably for Panfrost) do sleep.

Instead let's rename drm_sched_cleanup_jobs() to
drm_sched_get_cleanup_job() and simply return a job for processing if
there is one. The caller can then call the free_job() callback outside
the wait_event_interruptible() where sleeping is possible before
re-checking and returning to sleep if necessary.

Tested-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Fixes: 5918045c4ed4 ("drm/scheduler: rework job destruction")
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v4:
 * Don't initialise job in drm_sched_get_cleanup_job()
 * Change while loop into if in drm_sched_main()

 drivers/gpu/drm/scheduler/sched_main.c | 43 ++++++++++++++------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 9a0ee74d82dc..d4cc7289147e 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -622,43 +622,41 @@ static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb)
 }
 
 /**
- * drm_sched_cleanup_jobs - destroy finished jobs
+ * drm_sched_get_cleanup_job - fetch the next finished job to be destroyed
  *
  * @sched: scheduler instance
  *
- * Remove all finished jobs from the mirror list and destroy them.
+ * Returns the next finished job from the mirror list (if there is one)
+ * ready for it to be destroyed.
  */
-static void drm_sched_cleanup_jobs(struct drm_gpu_scheduler *sched)
+static struct drm_sched_job *
+drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)
 {
+	struct drm_sched_job *job;
 	unsigned long flags;
 
 	/* Don't destroy jobs while the timeout worker is running */
 	if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
 	    !cancel_delayed_work(&sched->work_tdr))
-		return;
-
+		return NULL;
 
-	while (!list_empty(&sched->ring_mirror_list)) {
-		struct drm_sched_job *job;
+	spin_lock_irqsave(&sched->job_list_lock, flags);
 
-		job = list_first_entry(&sched->ring_mirror_list,
+	job = list_first_entry_or_null(&sched->ring_mirror_list,
 				       struct drm_sched_job, node);
-		if (!dma_fence_is_signaled(&job->s_fence->finished))
-			break;
 
-		spin_lock_irqsave(&sched->job_list_lock, flags);
+	if (job && dma_fence_is_signaled(&job->s_fence->finished)) {
 		/* remove job from ring_mirror_list */
 		list_del_init(&job->node);
-		spin_unlock_irqrestore(&sched->job_list_lock, flags);
-
-		sched->ops->free_job(job);
+	} else {
+		job = NULL;
+		/* queue timeout for next job */
+		drm_sched_start_timeout(sched);
 	}
 
-	/* queue timeout for next job */
-	spin_lock_irqsave(&sched->job_list_lock, flags);
-	drm_sched_start_timeout(sched);
 	spin_unlock_irqrestore(&sched->job_list_lock, flags);
 
+	return job;
 }
 
 /**
@@ -698,12 +696,19 @@ static int drm_sched_main(void *param)
 		struct drm_sched_fence *s_fence;
 		struct drm_sched_job *sched_job;
 		struct dma_fence *fence;
+		struct drm_sched_job *cleanup_job = NULL;
 
 		wait_event_interruptible(sched->wake_up_worker,
-					 (drm_sched_cleanup_jobs(sched),
+					 (cleanup_job = drm_sched_get_cleanup_job(sched)) ||
 					 (!drm_sched_blocked(sched) &&
 					  (entity = drm_sched_select_entity(sched))) ||
-					 kthread_should_stop()));
+					 kthread_should_stop());
+
+		if (cleanup_job) {
+			sched->ops->free_job(cleanup_job);
+			/* queue timeout for next job */
+			drm_sched_start_timeout(sched);
+		}
 
 		if (!entity)
 			continue;
-- 
2.20.1

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH v5] drm: Don't free jobs in wait_event_interruptible()
@ 2019-10-25 11:00   ` Koenig, Christian
  0 siblings, 0 replies; 4+ messages in thread
From: Koenig, Christian @ 2019-10-25 11:00 UTC (permalink / raw)
  To: Steven Price, Daniel Vetter, David Airlie
  Cc: dri-devel, linux-kernel, Deucher, Alexander, Grodzovsky, Andrey,
	Erico Nunes, Sam Ravnborg, Sharat Masetty, Christian Gmeiner

Am 25.10.19 um 12:51 schrieb Steven Price:
> drm_sched_cleanup_jobs() attempts to free finished jobs, however because
> it is called as the condition of wait_event_interruptible() it must not
> sleep. Unfortunately some free callbacks (notably for Panfrost) do sleep.
>
> Instead let's rename drm_sched_cleanup_jobs() to
> drm_sched_get_cleanup_job() and simply return a job for processing if
> there is one. The caller can then call the free_job() callback outside
> the wait_event_interruptible() where sleeping is possible before
> re-checking and returning to sleep if necessary.
>
> Tested-by: Christian Gmeiner <christian.gmeiner@gmail.com>
> Fixes: 5918045c4ed4 ("drm/scheduler: rework job destruction")
> Signed-off-by: Steven Price <steven.price@arm.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

Going to pick that up for drm-misc-next.

Thanks for the help,
Christian.

> ---
> Changes since v4:
>   * Don't initialise job in drm_sched_get_cleanup_job()
>   * Change while loop into if in drm_sched_main()
>
>   drivers/gpu/drm/scheduler/sched_main.c | 43 ++++++++++++++------------
>   1 file changed, 24 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index 9a0ee74d82dc..d4cc7289147e 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -622,43 +622,41 @@ static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb)
>   }
>   
>   /**
> - * drm_sched_cleanup_jobs - destroy finished jobs
> + * drm_sched_get_cleanup_job - fetch the next finished job to be destroyed
>    *
>    * @sched: scheduler instance
>    *
> - * Remove all finished jobs from the mirror list and destroy them.
> + * Returns the next finished job from the mirror list (if there is one)
> + * ready for it to be destroyed.
>    */
> -static void drm_sched_cleanup_jobs(struct drm_gpu_scheduler *sched)
> +static struct drm_sched_job *
> +drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)
>   {
> +	struct drm_sched_job *job;
>   	unsigned long flags;
>   
>   	/* Don't destroy jobs while the timeout worker is running */
>   	if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
>   	    !cancel_delayed_work(&sched->work_tdr))
> -		return;
> -
> +		return NULL;
>   
> -	while (!list_empty(&sched->ring_mirror_list)) {
> -		struct drm_sched_job *job;
> +	spin_lock_irqsave(&sched->job_list_lock, flags);
>   
> -		job = list_first_entry(&sched->ring_mirror_list,
> +	job = list_first_entry_or_null(&sched->ring_mirror_list,
>   				       struct drm_sched_job, node);
> -		if (!dma_fence_is_signaled(&job->s_fence->finished))
> -			break;
>   
> -		spin_lock_irqsave(&sched->job_list_lock, flags);
> +	if (job && dma_fence_is_signaled(&job->s_fence->finished)) {
>   		/* remove job from ring_mirror_list */
>   		list_del_init(&job->node);
> -		spin_unlock_irqrestore(&sched->job_list_lock, flags);
> -
> -		sched->ops->free_job(job);
> +	} else {
> +		job = NULL;
> +		/* queue timeout for next job */
> +		drm_sched_start_timeout(sched);
>   	}
>   
> -	/* queue timeout for next job */
> -	spin_lock_irqsave(&sched->job_list_lock, flags);
> -	drm_sched_start_timeout(sched);
>   	spin_unlock_irqrestore(&sched->job_list_lock, flags);
>   
> +	return job;
>   }
>   
>   /**
> @@ -698,12 +696,19 @@ static int drm_sched_main(void *param)
>   		struct drm_sched_fence *s_fence;
>   		struct drm_sched_job *sched_job;
>   		struct dma_fence *fence;
> +		struct drm_sched_job *cleanup_job = NULL;
>   
>   		wait_event_interruptible(sched->wake_up_worker,
> -					 (drm_sched_cleanup_jobs(sched),
> +					 (cleanup_job = drm_sched_get_cleanup_job(sched)) ||
>   					 (!drm_sched_blocked(sched) &&
>   					  (entity = drm_sched_select_entity(sched))) ||
> -					 kthread_should_stop()));
> +					 kthread_should_stop());
> +
> +		if (cleanup_job) {
> +			sched->ops->free_job(cleanup_job);
> +			/* queue timeout for next job */
> +			drm_sched_start_timeout(sched);
> +		}
>   
>   		if (!entity)
>   			continue;


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH v5] drm: Don't free jobs in wait_event_interruptible()
@ 2019-10-25 11:00   ` Koenig, Christian
  0 siblings, 0 replies; 4+ messages in thread
From: Koenig, Christian @ 2019-10-25 11:00 UTC (permalink / raw)
  To: Steven Price, Daniel Vetter, David Airlie
  Cc: Sharat Masetty, linux-kernel, dri-devel, Deucher, Alexander,
	Sam Ravnborg, Erico Nunes

Am 25.10.19 um 12:51 schrieb Steven Price:
> drm_sched_cleanup_jobs() attempts to free finished jobs, however because
> it is called as the condition of wait_event_interruptible() it must not
> sleep. Unfortunately some free callbacks (notably for Panfrost) do sleep.
>
> Instead let's rename drm_sched_cleanup_jobs() to
> drm_sched_get_cleanup_job() and simply return a job for processing if
> there is one. The caller can then call the free_job() callback outside
> the wait_event_interruptible() where sleeping is possible before
> re-checking and returning to sleep if necessary.
>
> Tested-by: Christian Gmeiner <christian.gmeiner@gmail.com>
> Fixes: 5918045c4ed4 ("drm/scheduler: rework job destruction")
> Signed-off-by: Steven Price <steven.price@arm.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

Going to pick that up for drm-misc-next.

Thanks for the help,
Christian.

> ---
> Changes since v4:
>   * Don't initialise job in drm_sched_get_cleanup_job()
>   * Change while loop into if in drm_sched_main()
>
>   drivers/gpu/drm/scheduler/sched_main.c | 43 ++++++++++++++------------
>   1 file changed, 24 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index 9a0ee74d82dc..d4cc7289147e 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -622,43 +622,41 @@ static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb)
>   }
>   
>   /**
> - * drm_sched_cleanup_jobs - destroy finished jobs
> + * drm_sched_get_cleanup_job - fetch the next finished job to be destroyed
>    *
>    * @sched: scheduler instance
>    *
> - * Remove all finished jobs from the mirror list and destroy them.
> + * Returns the next finished job from the mirror list (if there is one)
> + * ready for it to be destroyed.
>    */
> -static void drm_sched_cleanup_jobs(struct drm_gpu_scheduler *sched)
> +static struct drm_sched_job *
> +drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)
>   {
> +	struct drm_sched_job *job;
>   	unsigned long flags;
>   
>   	/* Don't destroy jobs while the timeout worker is running */
>   	if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
>   	    !cancel_delayed_work(&sched->work_tdr))
> -		return;
> -
> +		return NULL;
>   
> -	while (!list_empty(&sched->ring_mirror_list)) {
> -		struct drm_sched_job *job;
> +	spin_lock_irqsave(&sched->job_list_lock, flags);
>   
> -		job = list_first_entry(&sched->ring_mirror_list,
> +	job = list_first_entry_or_null(&sched->ring_mirror_list,
>   				       struct drm_sched_job, node);
> -		if (!dma_fence_is_signaled(&job->s_fence->finished))
> -			break;
>   
> -		spin_lock_irqsave(&sched->job_list_lock, flags);
> +	if (job && dma_fence_is_signaled(&job->s_fence->finished)) {
>   		/* remove job from ring_mirror_list */
>   		list_del_init(&job->node);
> -		spin_unlock_irqrestore(&sched->job_list_lock, flags);
> -
> -		sched->ops->free_job(job);
> +	} else {
> +		job = NULL;
> +		/* queue timeout for next job */
> +		drm_sched_start_timeout(sched);
>   	}
>   
> -	/* queue timeout for next job */
> -	spin_lock_irqsave(&sched->job_list_lock, flags);
> -	drm_sched_start_timeout(sched);
>   	spin_unlock_irqrestore(&sched->job_list_lock, flags);
>   
> +	return job;
>   }
>   
>   /**
> @@ -698,12 +696,19 @@ static int drm_sched_main(void *param)
>   		struct drm_sched_fence *s_fence;
>   		struct drm_sched_job *sched_job;
>   		struct dma_fence *fence;
> +		struct drm_sched_job *cleanup_job = NULL;
>   
>   		wait_event_interruptible(sched->wake_up_worker,
> -					 (drm_sched_cleanup_jobs(sched),
> +					 (cleanup_job = drm_sched_get_cleanup_job(sched)) ||
>   					 (!drm_sched_blocked(sched) &&
>   					  (entity = drm_sched_select_entity(sched))) ||
> -					 kthread_should_stop()));
> +					 kthread_should_stop());
> +
> +		if (cleanup_job) {
> +			sched->ops->free_job(cleanup_job);
> +			/* queue timeout for next job */
> +			drm_sched_start_timeout(sched);
> +		}
>   
>   		if (!entity)
>   			continue;

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dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-10-25 11:00 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-25 10:51 [PATCH v5] drm: Don't free jobs in wait_event_interruptible() Steven Price
2019-10-25 10:51 ` Steven Price
2019-10-25 11:00 ` Koenig, Christian
2019-10-25 11:00   ` Koenig, Christian

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