Re: [PATCH 07/10] drm/ttm: use ttm_bo_lru_for_each_reserved_guarded in evict_all

[Thomas Hellström]

On Fri, 2026-07-03 at 18:31 +0200, Natalie Vock wrote:
> From: Christian König <christian.koenig@xxxxxxx>
> 
> Use the for_each loop to evict all BOs of an resource manager as
> well.
> 
> Greately simplifying the handling and finally allows us to
> remove ttm_bo_evict_first().
> 
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> Signed-off-by: Natalie Vock <natalie.vock@xxxxxx>

Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>

> ---
>  drivers/gpu/drm/ttm/ttm_bo.c       | 51 +---------------------------
> ----------
>  drivers/gpu/drm/ttm/ttm_resource.c | 22 ++++++++++------
>  include/drm/ttm/ttm_bo.h           |  1 +
>  3 files changed, 17 insertions(+), 57 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
> b/drivers/gpu/drm/ttm/ttm_bo.c
> index 54f01611ec823..80933ba6aada9 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -351,8 +351,7 @@ static int ttm_bo_bounce_temp_buffer(struct
> ttm_buffer_object *bo,
>  	return 0;
>  }
>  
> -static int ttm_bo_evict(struct ttm_buffer_object *bo,
> -			struct ttm_operation_ctx *ctx)
> +int ttm_bo_evict(struct ttm_buffer_object *bo, struct
> ttm_operation_ctx *ctx)
>  {
>  	struct ttm_resource *evict_mem;
>  	struct ttm_placement placement;
> @@ -437,54 +436,6 @@ bool ttm_bo_eviction_valuable(struct
> ttm_buffer_object *bo,
>  }
>  EXPORT_SYMBOL(ttm_bo_eviction_valuable);
>  
> -/**
> - * ttm_bo_evict_first() - Evict the first bo on the manager's LRU
> list.
> - * @bdev: The ttm device.
> - * @man: The manager whose bo to evict.
> - * @ctx: The TTM operation ctx governing the eviction.
> - *
> - * Return: 0 if successful or the resource disappeared. Negative
> error code on error.
> - */
> -int ttm_bo_evict_first(struct ttm_device *bdev, struct
> ttm_resource_manager *man,
> -		       struct ttm_operation_ctx *ctx)
> -{
> -	struct ttm_resource_cursor cursor;
> -	struct ttm_buffer_object *bo;
> -	struct ttm_resource *res;
> -	unsigned int mem_type;
> -	int ret = 0;
> -
> -	spin_lock(&bdev->lru_lock);
> -	ttm_resource_cursor_init(&cursor, man);
> -	res = ttm_resource_manager_first(&cursor);
> -	ttm_resource_cursor_fini(&cursor);
> -	if (!res) {
> -		ret = -ENOENT;
> -		goto out_no_ref;
> -	}
> -	bo = res->bo;
> -	if (!ttm_bo_get_unless_zero(bo))
> -		goto out_no_ref;
> -	mem_type = res->mem_type;
> -	spin_unlock(&bdev->lru_lock);
> -	ret = ttm_bo_reserve(bo, ctx->interruptible, ctx-
> >no_wait_gpu, NULL);
> -	if (ret)
> -		goto out_no_lock;
> -	if (!bo->resource || bo->resource->mem_type != mem_type)
> -		goto out_bo_moved;
> -
> -	ret = ttm_bo_evict(bo, ctx);
> -out_bo_moved:
> -	dma_resv_unlock(bo->base.resv);
> -out_no_lock:
> -	ttm_bo_put(bo);
> -	return ret;
> -
> -out_no_ref:
> -	spin_unlock(&bdev->lru_lock);
> -	return ret;
> -}
> -
>  /**
>   * struct ttm_bo_evict_walk - Parameters for the evict walk.
>   */
> diff --git a/drivers/gpu/drm/ttm/ttm_resource.c
> b/drivers/gpu/drm/ttm/ttm_resource.c
> index 154d6739256f8..cf3fc3a594388 100644
> --- a/drivers/gpu/drm/ttm/ttm_resource.c
> +++ b/drivers/gpu/drm/ttm/ttm_resource.c
> @@ -561,17 +561,25 @@ EXPORT_SYMBOL(ttm_resource_manager_init);
>  int ttm_resource_manager_evict_all(struct ttm_device *bdev,
>  				   struct ttm_resource_manager *man)
>  {
> -	struct ttm_operation_ctx ctx = { };
> +	struct ttm_bo_lru_cursor cursor;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_operation_ctx ctx = {
> +		.interruptible = false,
> +		.no_wait_gpu = false,
> +	};
> +	struct ttm_lru_walk_arg arg = {
> +		.ctx = &ctx,
> +		.trylock_only = true
> +	};
>  	struct dma_fence *fence;
>  	int ret, i;
>  
> -	do {
> -		ret = ttm_bo_evict_first(bdev, man, &ctx);
> +	ttm_bo_lru_for_each_reserved_guarded(&cursor, man, &arg, bo)
> {
> +		ret = ttm_bo_evict(bo, &ctx);
> +		if (ret)
> +			return ret;
>  		cond_resched();
> -	} while (!ret);
> -
> -	if (ret && ret != -ENOENT)
> -		return ret;
> +	}
>  
>  	ret = 0;
>  
> diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
> index bbed63064c9a9..a4060e44d23d0 100644
> --- a/include/drm/ttm/ttm_bo.h
> +++ b/include/drm/ttm/ttm_bo.h
> @@ -389,6 +389,7 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
>  void ttm_bo_fini(struct ttm_buffer_object *bo);
>  void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
>  			  struct ttm_lru_bulk_move *bulk);
> +int ttm_bo_evict(struct ttm_buffer_object *bo, struct
> ttm_operation_ctx *ctx);
>  bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
>  			      const struct ttm_place *place);
>  int ttm_bo_init_reserved(struct ttm_device *bdev, struct
> ttm_buffer_object *bo,