[Intel-gfx] [PATCH 17/26] drm/i915: use new iterator in i915_gem_object_wait_priority

[Tvrtko Ursulin]

On 13/09/2021 14:16, Christian König wrote:
> Simplifying the code a bit.
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/i915/gem/i915_gem_wait.c | 29 ++++--------------------
>   1 file changed, 5 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_wait.c b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
> index 13174541f6c8..e2173a55e527 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_wait.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
> @@ -120,31 +120,12 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
>   			      unsigned int flags,
>   			      const struct i915_sched_attr *attr)
>   {
> -	struct dma_fence *excl;
> -
> -	if (flags & I915_WAIT_ALL) {
> -		struct dma_fence **shared;
> -		unsigned int count, i;
> -		int ret;
> -
> -		ret = dma_resv_get_fences(obj->base.resv, &excl, &count,
> -					  &shared);
> -		if (ret)
> -			return ret;
> -
> -		for (i = 0; i < count; i++) {
> -			i915_gem_fence_wait_priority(shared[i], attr);
> -			dma_fence_put(shared[i]);
> -		}
> -
> -		kfree(shared);
> -	} else {
> -		excl = dma_resv_get_excl_unlocked(obj->base.resv);
> -	}
> +	struct dma_resv_cursor cursor;
> +	struct dma_fence *fence;
>   
> -	if (excl) {
> -		i915_gem_fence_wait_priority(excl, attr);
> -		dma_fence_put(excl);
> +	dma_resv_for_each_fence_unlocked(obj->base.resv, &cursor,
> +					 flags & I915_WAIT_ALL, fence) {
> +		i915_gem_fence_wait_priority(fence, attr);

Do you know if the RCU lock is actually held here? I tried following the 
KMS code paths but got lost in core helpers and driver vfuncs.

Regards,

Tvrtko

>   	}
>   	return 0;
>   }
>