[PATCH 1/4] drm/amdgpu: Optimization of critical section

[Christian König]

Am 12.06.2017 um 22:31 schrieb Alex Xie:
> This patch is to move a loop of unref BOs and
> several memory free function calls out of
> critical sections.
>
> Signed-off-by: Alex Xie <AlexBin.Xie at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
> index a664987..02c138f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
> @@ -75,9 +75,12 @@ static void amdgpu_bo_list_destroy(struct amdgpu_fpriv *fpriv, int id)
>   		/* Another user may have a reference to this list still */
>   		mutex_lock(&list->lock);
>   		mutex_unlock(&list->lock);
> +		mutex_unlock(&fpriv->bo_list_lock);
>   		amdgpu_bo_list_free(list);
>   	}
> -	mutex_unlock(&fpriv->bo_list_lock);
> +	else {
> +		mutex_unlock(&fpriv->bo_list_lock);
> +	}

You could move the unlock of bo_list_lock even before the if.

But since you pointed it out there is quite a bug in this function:
>                 /* Another user may have a reference to this list still */
>                 mutex_lock(&list->lock);
>                 mutex_unlock(&list->lock);
Not sure if that is still up to date, but that use case used to be 
illegal with mutexes.

Christian.

>   }
>   
>   static int amdgpu_bo_list_set(struct amdgpu_device *adev,