On 2021-12-07 9:59 a.m., Philip Yang wrote:
For userptr bo, if adev is not in IOMMU isolation mode, multiple GPUs
use same system memory page dma mapping address, they can share the
original mem->bo in attachment to reduce dma address array memory usage.

Signed-off-by: Philip Yang <[email protected]>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 12 ++++++++----
  1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index b8490789eef4..03807ed1f6e2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -708,10 +708,14 @@ static int kfd_mem_attach(struct amdgpu_device *adev, 
struct kgd_mem *mem,
                pr_debug("\t add VA 0x%llx - 0x%llx to vm %p\n", va,
                         va + bo_size, vm);
- if (adev == bo_adev || (mem->domain == AMDGPU_GEM_DOMAIN_VRAM &&
-                                       amdgpu_xgmi_same_hive(adev, bo_adev))) {
-                       /* Mappings on the local GPU and VRAM mappings in the
-                        * local hive share the original BO
+               if (adev == bo_adev ||
+                   (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) &&
+                    !adev->iommu_isolation) ||
+                   (mem->domain == AMDGPU_GEM_DOMAIN_VRAM &&
+                    amdgpu_xgmi_same_hive(adev, bo_adev))) {

For the sake of readability I'd ignore the 80-column rule here (which isn't a hard rule any more). It could apply in the same way to GTT. This would be clearer:

+               if (adev == bo_adev ||
+                   (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) && 
adev->ram_is_direct_mapped) ||
+                   (mem->domain == AMDGPU_GEM_DOMAIN_VRAM && 
amdgpu_xgmi_same_hive(adev, bo_adev))) {

Regards,
  Felix


+                       /* Mappings on the local GPU, or VRAM mappings in the
+                        * local hive, or userptr mapping IOMMU is not isolation
+                        * mode share the original BO
                         */
                        attachment[i]->type = KFD_MEM_ATT_SHARED;
                        bo[i] = mem->bo;

Reply via email to