[PATCH] drm/scheduler: Unwrap job dependencies

[PATCH] drm/scheduler: Unwrap job dependencies

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

Container fences have burner contexts, which makes the trick to store at
most one fence per context somewhat useless if we don't unwrap array or
chain fences.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/scheduler/sched_main.c | 47 ++++++++++++++++++--------
 1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 9762464e3f99..16b550949c57 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -52,6 +52,7 @@
 #include <linux/wait.h>
 #include <linux/sched.h>
 #include <linux/completion.h>
+#include <linux/dma-fence-unwrap.h>
 #include <linux/dma-resv.h>
 #include <uapi/linux/sched/types.h>
 
@@ -684,27 +685,14 @@ void drm_sched_job_arm(struct drm_sched_job *job)
 }
 EXPORT_SYMBOL(drm_sched_job_arm);
 
-/**
- * drm_sched_job_add_dependency - adds the fence as a job dependency
- * @job: scheduler job to add the dependencies to
- * @fence: the dma_fence to add to the list of dependencies.
- *
- * Note that @fence is consumed in both the success and error cases.
- *
- * Returns:
- * 0 on success, or an error on failing to expand the array.
- */
-int drm_sched_job_add_dependency(struct drm_sched_job *job,
-				 struct dma_fence *fence)
+static int drm_sched_job_add_single_dependency(struct drm_sched_job *job,
+					       struct dma_fence *fence)
 {
 	struct dma_fence *entry;
 	unsigned long index;
 	u32 id = 0;
 	int ret;
 
-	if (!fence)
-		return 0;
-
 	/* Deduplicate if we already depend on a fence from the same context.
 	 * This lets the size of the array of deps scale with the number of
 	 * engines involved, rather than the number of BOs.
@@ -728,6 +716,35 @@ int drm_sched_job_add_dependency(struct drm_sched_job *job,
 
 	return ret;
 }
+
+/**
+ * drm_sched_job_add_dependency - adds the fence as a job dependency
+ * @job: scheduler job to add the dependencies to
+ * @fence: the dma_fence to add to the list of dependencies.
+ *
+ * Note that @fence is consumed in both the success and error cases.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_add_dependency(struct drm_sched_job *job,
+				 struct dma_fence *fence)
+{
+	struct dma_fence_unwrap iter;
+	struct dma_fence *f;
+	int ret = 0;
+
+	dma_fence_unwrap_for_each (f, &iter, fence) {
+		dma_fence_get(f);
+		ret = drm_sched_job_add_single_dependency(job, f);
+		if (ret)
+			break;
+	}
+
+	dma_fence_put(fence);
+
+	return ret;
+}
 EXPORT_SYMBOL(drm_sched_job_add_dependency);
 
 /**
-- 
2.42.0

Re: [PATCH] drm/scheduler: Unwrap job dependencies

[Luben Tuikov]

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Hi,

On 2023-12-05 14:02, Rob Clark wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> Container fences have burner contexts, which makes the trick to store at
> most one fence per context somewhat useless if we don't unwrap array or
> chain fences.
> 
> Signed-off-by: Rob Clark <robdclark@chromium.org>

Link: https://lore.kernel.org/all/20230322224403.35742-1-robdclark@gmail.com/

Let's include a link to the original thread, as the main discussion can be found
therein.

Christian, could you review this patch please?

Thanks!
-- 
Regards,
Luben

> ---
>  drivers/gpu/drm/scheduler/sched_main.c | 47 ++++++++++++++++++--------
>  1 file changed, 32 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index 9762464e3f99..16b550949c57 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -52,6 +52,7 @@
>  #include <linux/wait.h>
>  #include <linux/sched.h>
>  #include <linux/completion.h>
> +#include <linux/dma-fence-unwrap.h>
>  #include <linux/dma-resv.h>
>  #include <uapi/linux/sched/types.h>
>  
> @@ -684,27 +685,14 @@ void drm_sched_job_arm(struct drm_sched_job *job)
>  }
>  EXPORT_SYMBOL(drm_sched_job_arm);
>  
> -/**
> - * drm_sched_job_add_dependency - adds the fence as a job dependency
> - * @job: scheduler job to add the dependencies to
> - * @fence: the dma_fence to add to the list of dependencies.
> - *
> - * Note that @fence is consumed in both the success and error cases.
> - *
> - * Returns:
> - * 0 on success, or an error on failing to expand the array.
> - */
> -int drm_sched_job_add_dependency(struct drm_sched_job *job,
> -				 struct dma_fence *fence)
> +static int drm_sched_job_add_single_dependency(struct drm_sched_job *job,
> +					       struct dma_fence *fence)
>  {
>  	struct dma_fence *entry;
>  	unsigned long index;
>  	u32 id = 0;
>  	int ret;
>  
> -	if (!fence)
> -		return 0;
> -
>  	/* Deduplicate if we already depend on a fence from the same context.
>  	 * This lets the size of the array of deps scale with the number of
>  	 * engines involved, rather than the number of BOs.
> @@ -728,6 +716,35 @@ int drm_sched_job_add_dependency(struct drm_sched_job *job,
>  
>  	return ret;
>  }
> +
> +/**
> + * drm_sched_job_add_dependency - adds the fence as a job dependency
> + * @job: scheduler job to add the dependencies to
> + * @fence: the dma_fence to add to the list of dependencies.
> + *
> + * Note that @fence is consumed in both the success and error cases.
> + *
> + * Returns:
> + * 0 on success, or an error on failing to expand the array.
> + */
> +int drm_sched_job_add_dependency(struct drm_sched_job *job,
> +				 struct dma_fence *fence)
> +{
> +	struct dma_fence_unwrap iter;
> +	struct dma_fence *f;
> +	int ret = 0;
> +
> +	dma_fence_unwrap_for_each (f, &iter, fence) {
> +		dma_fence_get(f);
> +		ret = drm_sched_job_add_single_dependency(job, f);
> +		if (ret)
> +			break;
> +	}
> +
> +	dma_fence_put(fence);
> +
> +	return ret;
> +}
>  EXPORT_SYMBOL(drm_sched_job_add_dependency);
>  
>  /**

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Re: [Linaro-mm-sig] [PATCH] drm/scheduler: Unwrap job dependencies

[Christian König]

Am 05.12.23 um 20:02 schrieb Rob Clark:
> From: Rob Clark <robdclark@chromium.org>
>
> Container fences have burner contexts, which makes the trick to store at
> most one fence per context somewhat useless if we don't unwrap array or
> chain fences.
>
> Signed-off-by: Rob Clark <robdclark@chromium.org>

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

> ---
>   drivers/gpu/drm/scheduler/sched_main.c | 47 ++++++++++++++++++--------
>   1 file changed, 32 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index 9762464e3f99..16b550949c57 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -52,6 +52,7 @@
>   #include <linux/wait.h>
>   #include <linux/sched.h>
>   #include <linux/completion.h>
> +#include <linux/dma-fence-unwrap.h>
>   #include <linux/dma-resv.h>
>   #include <uapi/linux/sched/types.h>
>   
> @@ -684,27 +685,14 @@ void drm_sched_job_arm(struct drm_sched_job *job)
>   }
>   EXPORT_SYMBOL(drm_sched_job_arm);
>   
> -/**
> - * drm_sched_job_add_dependency - adds the fence as a job dependency
> - * @job: scheduler job to add the dependencies to
> - * @fence: the dma_fence to add to the list of dependencies.
> - *
> - * Note that @fence is consumed in both the success and error cases.
> - *
> - * Returns:
> - * 0 on success, or an error on failing to expand the array.
> - */
> -int drm_sched_job_add_dependency(struct drm_sched_job *job,
> -				 struct dma_fence *fence)
> +static int drm_sched_job_add_single_dependency(struct drm_sched_job *job,
> +					       struct dma_fence *fence)
>   {
>   	struct dma_fence *entry;
>   	unsigned long index;
>   	u32 id = 0;
>   	int ret;
>   
> -	if (!fence)
> -		return 0;
> -
>   	/* Deduplicate if we already depend on a fence from the same context.
>   	 * This lets the size of the array of deps scale with the number of
>   	 * engines involved, rather than the number of BOs.
> @@ -728,6 +716,35 @@ int drm_sched_job_add_dependency(struct drm_sched_job *job,
>   
>   	return ret;
>   }
> +
> +/**
> + * drm_sched_job_add_dependency - adds the fence as a job dependency
> + * @job: scheduler job to add the dependencies to
> + * @fence: the dma_fence to add to the list of dependencies.
> + *
> + * Note that @fence is consumed in both the success and error cases.
> + *
> + * Returns:
> + * 0 on success, or an error on failing to expand the array.
> + */
> +int drm_sched_job_add_dependency(struct drm_sched_job *job,
> +				 struct dma_fence *fence)
> +{
> +	struct dma_fence_unwrap iter;
> +	struct dma_fence *f;
> +	int ret = 0;
> +
> +	dma_fence_unwrap_for_each (f, &iter, fence) {
> +		dma_fence_get(f);
> +		ret = drm_sched_job_add_single_dependency(job, f);
> +		if (ret)
> +			break;
> +	}
> +
> +	dma_fence_put(fence);
> +
> +	return ret;
> +}
>   EXPORT_SYMBOL(drm_sched_job_add_dependency);
>   
>   /**