[PATCH v2 2/3] drm/amdgpu: Use preemptible placement for KFD

[Christian König]

Am 21.05.21 um 04:22 schrieb Felix Kuehling:
> KFD userptr BOs and SG BOs used for DMA mappings can be preempted with
> CWSR. Therefore we can use preemptible placement and avoid unwanted
> evictions due to GTT accounting.
>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>

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

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> index 928e8d57cd08..2b8b89535198 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> @@ -621,8 +621,8 @@ kfd_mem_attach_userptr(struct amdgpu_device *adev, struct kgd_mem *mem,
>   
>   	ret = amdgpu_gem_object_create(adev, bo_size, 1,
>   				       AMDGPU_GEM_DOMAIN_CPU,
> -				       0, ttm_bo_type_sg,
> -				       mem->bo->tbo.base.resv,
> +				       AMDGPU_GEM_CREATE_PREEMPTIBLE,
> +				       ttm_bo_type_sg, mem->bo->tbo.base.resv,
>   				       &gobj);
>   	if (ret)
>   		return ret;
> @@ -662,6 +662,7 @@ kfd_mem_attach_dmabuf(struct amdgpu_device *adev, struct kgd_mem *mem,
>   	dma_buf_put(mem->dmabuf);
>   
>   	*bo = gem_to_amdgpu_bo(gobj);
> +	(*bo)->flags |= AMDGPU_GEM_CREATE_PREEMPTIBLE;
>   	(*bo)->parent = amdgpu_bo_ref(mem->bo);
>   
>   	return 0;
> @@ -1410,7 +1411,7 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
>   	} else if (flags & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {
>   		domain = AMDGPU_GEM_DOMAIN_GTT;
>   		alloc_domain = AMDGPU_GEM_DOMAIN_CPU;
> -		alloc_flags = 0;
> +		alloc_flags = AMDGPU_GEM_CREATE_PREEMPTIBLE;
>   		if (!offset || !*offset)
>   			return -EINVAL;
>   		user_addr = untagged_addr(*offset);