On Fri, May 19, 2017 at 9:03 AM, Michel Dänzer <michel at daenzer.net> wrote: > On 19/05/17 12:04 PM, John Brooks wrote: >> Set GTT as the busy placement for newly created BOs that have the >> AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED flag, so that they don't cause >> established BOs to be evicted from visible VRAM. > > This is an interesting idea, but there are some issues with this patch. > > >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c >> index 365883d..655718a 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c >> @@ -392,6 +392,17 @@ int amdgpu_bo_create_restricted(struct amdgpu_device *adev, >> #endif >> >> amdgpu_fill_placement_to_bo(bo, placement); >> + >> + /* This is a new BO that wants to be CPU-visible; set GTT as the busy >> + * placement so that it does not evict established BOs from visible VRAM. >> + */ >> + if (domain & (AMDGPU_GEM_DOMAIN_VRAM | AMDGPU_GEM_DOMAIN_GTT) && > > Should be something like > > if (domain == (AMDGPU_GEM_DOMAIN_VRAM | AMDGPU_GEM_DOMAIN_GTT) && > > otherwise it would also match e.g. BOs with domain == > AMDGPU_GEM_DOMAIN_GTT and the AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED > flag set (not that this makes sense, but there's nothing to prevent it). I think it should be like this, which trivially rules out GTT and VRAM|GTT cases: if (domain == AMDGPU_GEM_DOMAIN_VRAM && Marek
