Mesa (master): winsys/amdgpu: always allow GTT placements on APUs

[Marek Olšák]

Module: Mesa
Branch: master
Commit: 7d2079908d9ef05ec3f35b7078833e57846cab5b
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7d2079908d9ef05ec3f35b7078833e57846cab5b

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Wed Mar 21 16:10:29 2018 -0400

winsys/amdgpu: always allow GTT placements on APUs

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

---

 src/gallium/winsys/amdgpu/drm/amdgpu_bo.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c b/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c
index 7740b46b7b..22b5a73143 100644
--- a/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c
+++ b/src/gallium/winsys/amdgpu/drm/amdgpu_bo.c
@@ -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)