Re: [PATCH v2 13/20] drm/amdgpu: use multiple entities in amdgpu_move_blit

Christian König
2025-11-17T09:12:53Z

On 11/13/25 17:05, Pierre-Eric Pelloux-Prayer wrote:
> Thanks to "drm/ttm: rework pipelined eviction fence handling", ttm
> can deal correctly with moves and evictions being executed from
> different contexts.
>
> Create several entities and use them in a round-robin fashion.
>
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 13 ++++++++++---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 1 +
> 2 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 486c701d0d5b..6c333dba7a35 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -401,6 +401,7 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
> {
> struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
> struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
> + struct amdgpu_ttm_buffer_entity *entity;
> struct amdgpu_copy_mem src, dst;
> struct dma_fence *fence = NULL;
> int r;
> @@ -412,8 +413,12 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
> src.offset = 0;
> dst.offset = 0;
>
> + int e = atomic_inc_return(&adev->mman.next_move_entity) %
> + adev->mman.num_move_entities;
> + entity = &adev->mman.move_entities[e];

Similar to clears this could be a sepatate function, but not a must have.

Reviewed-by: Christian König <christian.koenig@amd.com> either way.

Regards,
Christian.

> +
> r = amdgpu_ttm_copy_mem_to_mem(adev,
> - &adev->mman.move_entities[0],
> + entity,
> &src, &dst,
> new_mem->size,
> amdgpu_bo_encrypted(abo),
> @@ -426,7 +431,7 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
> (abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE)) {
> struct dma_fence *wipe_fence = NULL;
>
> - r = amdgpu_fill_buffer(&adev->mman.move_entities[0],
> + r = amdgpu_fill_buffer(entity,
> abo, 0, NULL, &wipe_fence, fence,
> AMDGPU_KERNEL_JOB_ID_MOVE_BLIT);
> if (r) {
> @@ -2179,7 +2184,8 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
> struct ttm_resource_manager *man = ttm_manager_type(&adev->mman.bdev, TTM_PL_VRAM);
> uint64_t size;
> int r, i, j;
> - u32 num_clear_entities, num_move_entities, windows, w;
> + u32 num_clear_entities, num_move_entities;
> + u32 windows, w;
>
> num_clear_entities = adev->sdma.num_instances;
> num_move_entities = MIN(adev->sdma.num_instances, TTM_NUM_MOVE_FENCES);
> @@ -2205,6 +2211,7 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
> }
>
> adev->mman.num_move_entities = num_move_entities;
> + atomic_set(&adev->mman.next_move_entity, 0);
> for (i = 0; i < num_move_entities; i++) {
> r = drm_sched_entity_init(&adev->mman.move_entities[i].base,
> DRM_SCHED_PRIORITY_NORMAL, &sched,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> index 781b0bdca56c..4844f001f590 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> @@ -76,6 +76,7 @@ struct amdgpu_mman {
> atomic_t next_clear_entity;
> u32 num_clear_entities;
> struct amdgpu_ttm_buffer_entity move_entities[TTM_NUM_MOVE_FENCES];
> + atomic_t next_move_entity;
> u32 num_move_entities;
>
> struct amdgpu_vram_mgr vram_mgr;