[1/3] dma-buf/sync_file: cleanup fence merging a bit

Message ID 20220426124637.329764-1-christian.koenig@amd.com (mailing list archive)
State Not Applicable
Headers
Series [1/3] dma-buf/sync_file: cleanup fence merging a bit |

Commit Message

Christian König April 26, 2022, 12:46 p.m. UTC
  krealloc_array() ignores attempts to reduce the array size, so the attempt
to save memory is completely pointless here.

Also move testing for the no fence case into sync_file_set_fence(), this
way we don't even touch the fence array when we don't have any fences.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/sync_file.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)
  

Comments

Daniel Vetter May 4, 2022, 8:34 a.m. UTC | #1
On Tue, Apr 26, 2022 at 02:46:35PM +0200, Christian König wrote:
> krealloc_array() ignores attempts to reduce the array size, so the attempt
> to save memory is completely pointless here.
> 
> Also move testing for the no fence case into sync_file_set_fence(), this
> way we don't even touch the fence array when we don't have any fences.
> 
> Signed-off-by: Christian König <christian.koenig@amd.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
>  drivers/dma-buf/sync_file.c | 21 +++++++--------------
>  1 file changed, 7 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
> index 514d213261df..0fe564539166 100644
> --- a/drivers/dma-buf/sync_file.c
> +++ b/drivers/dma-buf/sync_file.c
> @@ -157,9 +157,15 @@ static int sync_file_set_fence(struct sync_file *sync_file,
>  	 * we already own a new reference to the fence. For num_fence > 1
>  	 * we own the reference of the dma_fence_array creation.
>  	 */
> -	if (num_fences == 1) {
> +
> +	if (num_fences == 0) {
> +		sync_file->fence = dma_fence_get_stub();
> +		kfree(fences);
> +
> +	} else if (num_fences == 1) {
>  		sync_file->fence = fences[0];
>  		kfree(fences);
> +
>  	} else {
>  		array = dma_fence_array_create(num_fences, fences,
>  					       dma_fence_context_alloc(1),
> @@ -261,19 +267,6 @@ static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
>  		}
>  	}
>  
> -	if (index == 0)
> -		fences[index++] = dma_fence_get_stub();
> -
> -	if (num_fences > index) {
> -		struct dma_fence **tmp;
> -
> -		/* Keep going even when reducing the size failed */
> -		tmp = krealloc_array(fences, index, sizeof(*fences),
> -				     GFP_KERNEL);
> -		if (tmp)
> -			fences = tmp;
> -	}
> -
>  	if (sync_file_set_fence(sync_file, fences, index) < 0)
>  		goto err_put_fences;
>  
> -- 
> 2.25.1
>
  

Patch

diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index 514d213261df..0fe564539166 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -157,9 +157,15 @@  static int sync_file_set_fence(struct sync_file *sync_file,
 	 * we already own a new reference to the fence. For num_fence > 1
 	 * we own the reference of the dma_fence_array creation.
 	 */
-	if (num_fences == 1) {
+
+	if (num_fences == 0) {
+		sync_file->fence = dma_fence_get_stub();
+		kfree(fences);
+
+	} else if (num_fences == 1) {
 		sync_file->fence = fences[0];
 		kfree(fences);
+
 	} else {
 		array = dma_fence_array_create(num_fences, fences,
 					       dma_fence_context_alloc(1),
@@ -261,19 +267,6 @@  static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
 		}
 	}
 
-	if (index == 0)
-		fences[index++] = dma_fence_get_stub();
-
-	if (num_fences > index) {
-		struct dma_fence **tmp;
-
-		/* Keep going even when reducing the size failed */
-		tmp = krealloc_array(fences, index, sizeof(*fences),
-				     GFP_KERNEL);
-		if (tmp)
-			fences = tmp;
-	}
-
 	if (sync_file_set_fence(sync_file, fences, index) < 0)
 		goto err_put_fences;