winsys/amdgpu: always allow GTT placements on APUs
authorMarek Olšák <marek.olsak@amd.com>
Wed, 21 Mar 2018 20:10:29 +0000 (16:10 -0400)
committerMarek Olšák <marek.olsak@amd.com>
Mon, 26 Mar 2018 23:23:30 +0000 (19:23 -0400)
Reviewed-by: Christian König <christian.koenig@amd.com>
src/gallium/winsys/amdgpu/drm/amdgpu_bo.c

index 7740b46b7b9ef21b1c9931f495faaf2cc465b457..22b5a73143d24249c454caebcc907e20aff0d914 100644 (file)
@@ -409,14 +409,12 @@ static struct amdgpu_winsys_bo *amdgpu_create_bo(struct amdgpu_winsys *ws,
    if (initial_domain & RADEON_DOMAIN_GTT)
       request.preferred_heap |= AMDGPU_GEM_DOMAIN_GTT;
 
-   /* If VRAM is just stolen system memory, allow both VRAM and
-    * GTT, whichever has free space. If a buffer is evicted from
-    * VRAM to GTT, it will stay there.
-    *
-    * DRM 3.6.0 has good BO move throttling, so we can allow VRAM-only
-    * placements even with a low amount of stolen VRAM.
+   /* Since VRAM and GTT have almost the same performance on APUs, we could
+    * just set GTT. However, in order to decrease GTT(RAM) usage, which is
+    * 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 && ws->info.drm_minor < 6)
+   if (!ws->info.has_dedicated_vram)
       request.preferred_heap |= AMDGPU_GEM_DOMAIN_GTT;
 
    if (flags & RADEON_FLAG_NO_CPU_ACCESS)