[Intel-gfx] [PATCH 04/31] drm/i915: Only drop the batch-pool's object reference

[Joonas Lahtinen]

On ma, 2016-07-25 at 08:44 +0100, Chris Wilson wrote:
> The obj->batch_pool_link is only inspected when traversing the batch
> pool list and when on the batch pool list the object is referenced. Thus
> when freeing the batch pool list, we only need to unreference the object
> and do not have to worry about the obj->batch_pool_link.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem_batch_pool.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_batch_pool.c b/drivers/gpu/drm/i915/i915_gem_batch_pool.c
> index 3507b2753fd3..825981b5aa40 100644
> --- a/drivers/gpu/drm/i915/i915_gem_batch_pool.c
> +++ b/drivers/gpu/drm/i915/i915_gem_batch_pool.c
> @@ -68,15 +68,14 @@ void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool)
>  	WARN_ON(!mutex_is_locked(&pool->dev->struct_mutex));
>  
>  	for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++) {
> -		while (!list_empty(&pool->cache_list[n])) {
> -			struct drm_i915_gem_object *obj =
> -				list_first_entry(&pool->cache_list[n],
> -						 struct drm_i915_gem_object,
> -						 batch_pool_link);
> +		struct drm_i915_gem_object *obj, *next;
>  
> -			list_del(&obj->batch_pool_link);
> +		list_for_each_entry_safe(obj, next,

Why _safe? i915_gem_free_object does not touch the batch_pool_link.

Regards, Joonas

> +					 &pool->cache_list[n],
> +					 batch_pool_link)
>  			i915_gem_object_put(obj);
> -		}
> +
> +		INIT_LIST_HEAD(&pool->cache_list[n]);
>  	}
>  }
>  
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation