Commit 67f74302 authored by Christian König's avatar Christian König
Browse files

drm/nouveau: wait for the exclusive fence after the shared ones v2 



Always waiting for the exclusive fence resulted on some performance
regressions. So try to wait for the shared fences first, then the
exclusive fence should always be signaled already.

v2: fix incorrectly placed "(", add some comment why we do this.

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Tested-by: default avatarStefan Fritsch <sf@sfritsch.de>
Tested-by: default avatarDan Moulding <dmoulding@me.com>
Acked-by: default avatarBen Skeggs <bskeggs@redhat.com>
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Cc: <stable@vger.kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211209102335.18321-1-christian.koenig@amd.com
parent fc74881c

drivers/gpu/drm/nouveau/nouveau_fence.c

+15 −13
Original line number Diff line number Diff line
@@ -353,15 +353,22 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e 


		if (ret)

			return ret;

	}



		fobj = NULL;

	} else {

		fobj = dma_resv_shared_list(resv);

	fence = dma_resv_excl_fence(resv);

	}



	if (fence) {

	/* Waiting for the exclusive fence first causes performance regressions

	 * under some circumstances. So manually wait for the shared ones first.

	 */

	for (i = 0; i < (fobj ? fobj->shared_count : 0) && !ret; ++i) {

		struct nouveau_channel *prev = NULL;

		bool must_wait = true;



		fence = rcu_dereference_protected(fobj->shared[i],

						dma_resv_held(resv));



		f = nouveau_local_fence(fence, chan->drm);

		if (f) {

			rcu_read_lock();
@@ -373,20 +380,13 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e 


		if (must_wait)

			ret = dma_fence_wait(fence, intr);



		return ret;

	}



	if (!exclusive || !fobj)

		return ret;



	for (i = 0; i < fobj->shared_count && !ret; ++i) {

	fence = dma_resv_excl_fence(resv);

	if (fence) {

		struct nouveau_channel *prev = NULL;

		bool must_wait = true;



		fence = rcu_dereference_protected(fobj->shared[i],

						dma_resv_held(resv));



		f = nouveau_local_fence(fence, chan->drm);

		if (f) {

			rcu_read_lock();
@@ -398,6 +398,8 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e 


		if (must_wait)

			ret = dma_fence_wait(fence, intr);



		return ret;

	}



	return ret;