[Mesa-dev] [PATCH] winsys/amdgpu: Restrict allocation to GTT for small vram size

[Christian König]

Am 25.04.19 um 13:37 schrieb Agrawal, Akshu:
> To avoid evictions, use GTT only for allocation on devices with
> small vram size.
>
> Signed-off-by: Akshu Agrawal <akshu.agrawal at amd.com>
> ---
>   src/gallium/winsys/amdgpu/drm/amdgpu_bo.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c b/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c
> index 09cf9247755..aab801b6337 100644
> --- a/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c
> +++ b/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c
> @@ -486,8 +486,15 @@ static struct amdgpu_winsys_bo *amdgpu_create_bo(struct amdgpu_winsys *ws,
>          * shared with the OS, allow VRAM placements too. The idea is not to use
>          * VRAM usefully, but to use it so that it's not unused and wasted.
>          */
> -      if (!ws->info.has_dedicated_vram)
> +   if (!ws->info.has_dedicated_vram) {
> +      /* For devices having small VRAM size use GTT only to
> +       * avoid evictions.
> +       */
> +      if (ws->info.vram_size <= 16777216)
> +         request.preferred_heap = AMDGPU_GEM_DOMAIN_GTT;

Well that will certainly cause problems because it would result in 
scanout BOs to be forced into GTT.

Christian.

> +      else
>            request.preferred_heap |= AMDGPU_GEM_DOMAIN_GTT;
> +      }
>      }
>   
>      if (initial_domain & RADEON_DOMAIN_GTT)