Am 10.09.2018 um 11:34 schrieb Emily Deng:
> It will ramdomly have the dead lock issue when test TDR:
> 1. amdgpu_device_handle_vram_lost gets the lock shadow_list_lock
> 2. amdgpu_bo_create locked the bo's resv lock
> 3. amdgpu_bo_create_shadow is waiting for the shadow_list_lock
> 4. amdgpu_device_recover_vram_from_shadow is waiting for the bo's resv
> lock.
>
> v2:
> Make a local copy of the list
>
> Signed-off-by: Emily Deng <Emily.Deng at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 12 +++++++++++-
> drivers/gpu/drm/amd/amdgpu/amdgpu_object.h | 1 +
> 2 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index acfc63e..2b9f597 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3006,6 +3006,9 @@ static int amdgpu_device_handle_vram_lost(struct amdgpu_device *adev)
> long r = 1;
> int i = 0;
> long tmo;
> + struct list_head local_shadow_list;
> +
> + INIT_LIST_HEAD(&local_shadow_list);
>
> if (amdgpu_sriov_runtime(adev))
> tmo = msecs_to_jiffies(8000);
> @@ -3013,8 +3016,15 @@ static int amdgpu_device_handle_vram_lost(struct amdgpu_device *adev)
> tmo = msecs_to_jiffies(100);
>
> DRM_INFO("recover vram bo from shadow start\n");
> +
> mutex_lock(&adev->shadow_list_lock);
> list_for_each_entry_safe(bo, tmp, &adev->shadow_list, shadow_list) {
> + amdgpu_bo_ref(bo);
> + list_add_tail(&bo->copy_shadow_list, &local_shadow_list);
> + }
Please don't add an extra copy_shadow_list field to amdgpu_bo.
Instead just use bo->shadow list for this. When you hold a reference to
the BO it should not be removed from the shadow list.
Additional to that you can just use list_splice_init() to move the whole
shadow list to your local list.
Christian.
> + mutex_unlock(&adev->shadow_list_lock);
> +
> + list_for_each_entry_safe(bo, tmp, &local_shadow_list, copy_shadow_list) {
> next = NULL;
> amdgpu_device_recover_vram_from_shadow(adev, ring, bo, &next);
> if (fence) {
> @@ -3033,8 +3043,8 @@ static int amdgpu_device_handle_vram_lost(struct amdgpu_device *adev)
>
> dma_fence_put(fence);
> fence = next;
> + amdgpu_bo_unref(&bo);
> }
> - mutex_unlock(&adev->shadow_list_lock);
>
> if (fence) {
> r = dma_fence_wait_timeout(fence, false, tmo);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> index 907fdf4..cfee16c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> @@ -103,6 +103,7 @@ struct amdgpu_bo {
> struct list_head mn_list;
> struct list_head shadow_list;
> };
> + struct list_head copy_shadow_list;
>
> struct kgd_mem *kfd_bo;
> };
