From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huawei Xie Subject: [RFC PATCH] avail idx update optimizations Date: Fri, 22 Apr 2016 01:18:12 +0800 Message-ID: <1461259092-9309-1-git-send-email-huawei.xie@intel.com> To: dev@dpdk.org Return-path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id 9ACCD2C4B for ; Fri, 22 Apr 2016 11:12:37 +0200 (CEST) List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" eliminate unnecessary cache to cache transfer between virtio and vhost core --- drivers/net/virtio/virtqueue.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h index 4e9239e..8c46a83 100644 --- a/drivers/net/virtio/virtqueue.h +++ b/drivers/net/virtio/virtqueue.h @@ -302,7 +302,8 @@ vq_update_avail_ring(struct virtqueue *vq, uint16_t desc_idx) * descriptor. */ avail_idx = (uint16_t)(vq->vq_avail_idx & (vq->vq_nentries - 1)); - vq->vq_ring.avail->ring[avail_idx] = desc_idx; + if (unlikely(vq->vq_ring.avail->ring[avail_idx] != desc_idx)) + vq->vq_ring.avail->ring[avail_idx] = desc_idx; vq->vq_avail_idx++; } -- 2.4.3