Commit b4b4ff73 authored by Xianting Tian's avatar Xianting Tian Committed by Michael S. Tsirkin
Browse files

virtio_ring: add unlikely annotation for free descs check 



The 'if (vq->vq.num_free < descs_used)' check will almost always be false.

Signed-off-by: default avatarXianting Tian <xianting.tian@linux.alibaba.com>
Message-Id: <20220328105817.1028065-2-xianting.tian@linux.alibaba.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
parent 35c51e09

drivers/virtio/virtio_ring.c

+1 −1
Original line number Diff line number Diff line
@@ -517,7 +517,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, 
		descs_used = total_sg;

	}



	if (vq->vq.num_free < descs_used) {

	if (unlikely(vq->vq.num_free < descs_used)) {

		pr_debug("Can't add buf len %i - avail = %i\n",

			 descs_used, vq->vq.num_free);

		/* FIXME: for historical reasons, we force a notify here if