[Intel-gfx] [PATCH 16/17] drm/i915: Enable userspace to opt-out of implicit fencing

Joonas Lahtinen joonas.lahtinen at linux.intel.com
Tue Aug 30 08:45:10 UTC 2016


On su, 2016-08-28 at 21:46 +0100, Chris Wilson wrote:
> Userspace is faced with a dilemma. The kernel requires implicit fencing
> to manage resource usage (we always must wait for the GPU to finish
> before releasing its PTE) and for third parties. However, userspace may
> wish to avoid this serialisation if it is either using explicit fencing
> between parties and wants more fine-grained access to buffers (e.g. it
> may partition the buffer between uses and track fences on ranges rather
> than the implicit fences tracking the whole object). To whit, userspace

s/whit/with/?

> @@ -1199,21 +1199,23 @@ i915_gem_execbuffer_move_to_gpu(struct drm_i915_gem_request *req,
>  		struct drm_i915_gem_object *obj = vma->obj;
>  		struct reservation_object *resv;
>  
> -		if (obj->flags & other_rings) {
> -			ret = eb_await_bo(req, obj,
> -					  obj->base.pending_write_domain);
> -			if (ret)
> -				return ret;
> -		}
> +		if ((vma->exec_entry->flags & EXEC_OBJECT_ASYNC) == 0) {

if (!(a & FOO)) would again be more readable.

With the typo fixed;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation


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