Am 2021-11-22 um 7:39 a.m. schrieb Christian König:
> Partially revert commit 5f319c5c21b5909abb43d8aadc92a8aa549ee443.
>
> First of all this is illegal use of RCU to call dma_fence_enable_sw_signaling()
> since we don't hold a reference to the fence in question and can crash badly.
>
> Then the code doesn't seem to have the intended effect since only the
> exclusive fence is handled, but the KFD fences are always added as shared fence.
>
> Only keep the handling to throw away the content of SVM BOs.
>
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 30b7dde496fc..b9cd32d25bc0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -113,17 +113,8 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
>
> abo = ttm_to_amdgpu_bo(bo);
> if (abo->flags & AMDGPU_AMDKFD_CREATE_SVM_BO) {
> - struct dma_fence *fence;
> - struct dma_resv *resv = &bo->base._resv;
> -
> - rcu_read_lock();
> - fence = rcu_dereference(resv->fence_excl);
> - if (fence && !fence->ops->signaled)
> - dma_fence_enable_sw_signaling(fence);
> -
> placement->num_placement = 0;
> placement->num_busy_placement = 0;
> - rcu_read_unlock();
> return;
> }
>
