[PATCH] drm/amdgpu: once more fix the call oder in amdgpu_ttm_move()

Alex Deucher alexdeucher at gmail.com
Thu Mar 21 21:01:01 UTC 2024


On Thu, Mar 21, 2024 at 8:52 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> This reverts drm/amdgpu: fix ftrace event amdgpu_bo_move always move
> on same heap. The basic problem here is that after the move the old
> location is simply not available any more.
>
> Some fixes where suggested, but essentially we should call the move

where -> were

> notification before actually moving things because only this way we have
> the correct order for DMA-buf and VM move notifications as well.
>
> Also rework the statistic handling so that we don't update the eviction
> counter before the move.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 15 +++----
>  drivers/gpu/drm/amd/amdgpu/amdgpu_object.h |  4 +-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    | 48 ++++++++++++----------
>  3 files changed, 37 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 425cebcc5cbf..eb7d824763b9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -1245,19 +1245,20 @@ int amdgpu_bo_get_metadata(struct amdgpu_bo *bo, void *buffer,
>   * amdgpu_bo_move_notify - notification about a memory move
>   * @bo: pointer to a buffer object
>   * @evict: if this move is evicting the buffer from the graphics address space
> + * @new_mem: new resource for backing the BO
>   *
>   * Marks the corresponding &amdgpu_bo buffer object as invalid, also performs
>   * bookkeeping.
>   * TTM driver callback which is called when ttm moves a buffer.
>   */
> -void amdgpu_bo_move_notify(struct ttm_buffer_object *bo, bool evict)
> +void amdgpu_bo_move_notify(struct ttm_buffer_object *bo,
> +                          bool evict,
> +                          struct ttm_resource *new_mem)
>  {
>         struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
> +       struct ttm_resource *old_mem = bo->resource;
>         struct amdgpu_bo *abo;
>
> -       if (!amdgpu_bo_is_amdgpu_bo(bo))
> -               return;
> -
>         abo = ttm_to_amdgpu_bo(bo);
>         amdgpu_vm_bo_invalidate(adev, abo, evict);
>
> @@ -1267,9 +1268,9 @@ void amdgpu_bo_move_notify(struct ttm_buffer_object *bo, bool evict)
>             bo->resource->mem_type != TTM_PL_SYSTEM)
>                 dma_buf_move_notify(abo->tbo.base.dma_buf);
>
> -       /* remember the eviction */
> -       if (evict)
> -               atomic64_inc(&adev->num_evictions);
> +       /* move_notify is called before move happens */
> +       trace_amdgpu_bo_move(abo, new_mem ? new_mem->mem_type : -1,
> +                            old_mem ? old_mem->mem_type : -1);
>  }
>
>  void amdgpu_bo_get_memory(struct amdgpu_bo *bo,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> index a3ea8a82db23..d28e21baef16 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> @@ -344,7 +344,9 @@ int amdgpu_bo_set_metadata (struct amdgpu_bo *bo, void *metadata,
>  int amdgpu_bo_get_metadata(struct amdgpu_bo *bo, void *buffer,
>                            size_t buffer_size, uint32_t *metadata_size,
>                            uint64_t *flags);
> -void amdgpu_bo_move_notify(struct ttm_buffer_object *bo, bool evict);
> +void amdgpu_bo_move_notify(struct ttm_buffer_object *bo,
> +                          bool evict,
> +                          struct ttm_resource *new_mem);
>  void amdgpu_bo_release_notify(struct ttm_buffer_object *bo);
>  vm_fault_t amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo);
>  void amdgpu_bo_fence(struct amdgpu_bo *bo, struct dma_fence *fence,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index a5ceec7820cf..460b23918bfc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -471,14 +471,16 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>
>         if (!old_mem || (old_mem->mem_type == TTM_PL_SYSTEM &&
>                          bo->ttm == NULL)) {
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_bo_move_null(bo, new_mem);
> -               goto out;
> +               return 0;
>         }
>         if (old_mem->mem_type == TTM_PL_SYSTEM &&
>             (new_mem->mem_type == TTM_PL_TT ||
>              new_mem->mem_type == AMDGPU_PL_PREEMPT)) {
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_bo_move_null(bo, new_mem);
> -               goto out;
> +               return 0;
>         }
>         if ((old_mem->mem_type == TTM_PL_TT ||
>              old_mem->mem_type == AMDGPU_PL_PREEMPT) &&
> @@ -488,9 +490,10 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>                         return r;
>
>                 amdgpu_ttm_backend_unbind(bo->bdev, bo->ttm);
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_resource_free(bo, &bo->resource);
>                 ttm_bo_assign_mem(bo, new_mem);
> -               goto out;
> +               return 0;
>         }
>
>         if (old_mem->mem_type == AMDGPU_PL_GDS ||
> @@ -502,8 +505,9 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>             new_mem->mem_type == AMDGPU_PL_OA ||
>             new_mem->mem_type == AMDGPU_PL_DOORBELL) {
>                 /* Nothing to save here */
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_bo_move_null(bo, new_mem);
> -               goto out;
> +               return 0;
>         }
>
>         if (bo->type == ttm_bo_type_device &&
> @@ -515,22 +519,23 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>                 abo->flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
>         }
>
> -       if (adev->mman.buffer_funcs_enabled) {
> -               if (((old_mem->mem_type == TTM_PL_SYSTEM &&
> -                     new_mem->mem_type == TTM_PL_VRAM) ||
> -                    (old_mem->mem_type == TTM_PL_VRAM &&
> -                     new_mem->mem_type == TTM_PL_SYSTEM))) {
> -                       hop->fpfn = 0;
> -                       hop->lpfn = 0;
> -                       hop->mem_type = TTM_PL_TT;
> -                       hop->flags = TTM_PL_FLAG_TEMPORARY;
> -                       return -EMULTIHOP;
> -               }
> +       if (adev->mman.buffer_funcs_enabled &&
> +           ((old_mem->mem_type == TTM_PL_SYSTEM &&
> +             new_mem->mem_type == TTM_PL_VRAM) ||
> +            (old_mem->mem_type == TTM_PL_VRAM &&
> +             new_mem->mem_type == TTM_PL_SYSTEM))) {
> +               hop->fpfn = 0;
> +               hop->lpfn = 0;
> +               hop->mem_type = TTM_PL_TT;
> +               hop->flags = TTM_PL_FLAG_TEMPORARY;
> +               return -EMULTIHOP;
> +       }
>
> +       amdgpu_bo_move_notify(bo, evict, new_mem);
> +       if (adev->mman.buffer_funcs_enabled)
>                 r = amdgpu_move_blit(bo, evict, new_mem, old_mem);
> -       } else {
> +       else
>                 r = -ENODEV;
> -       }
>
>         if (r) {
>                 /* Check that all memory is CPU accessible */
> @@ -545,11 +550,10 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>                         return r;
>         }
>
> -       trace_amdgpu_bo_move(abo, new_mem->mem_type, old_mem->mem_type);
> -out:
> -       /* update statistics */
> +       /* update statistics after the move */
> +       if (evict)
> +               atomic64_inc(&adev->num_evictions);
>         atomic64_add(bo->base.size, &adev->num_bytes_moved);
> -       amdgpu_bo_move_notify(bo, evict);
>         return 0;
>  }
>
> @@ -1551,7 +1555,7 @@ static int amdgpu_ttm_access_memory(struct ttm_buffer_object *bo,
>  static void
>  amdgpu_bo_delete_mem_notify(struct ttm_buffer_object *bo)
>  {
> -       amdgpu_bo_move_notify(bo, false);
> +       amdgpu_bo_move_notify(bo, false, NULL);
>  }
>
>  static struct ttm_device_funcs amdgpu_bo_driver = {
> --
> 2.34.1
>


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