From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [RFC PATCH net-next 3/6] virtio-net: small optimization on free_old_xmit_skbs() Date: Wed, 15 Oct 2014 15:25:27 +0800 Message-ID: <1413357930-45302-4-git-send-email-jasowang@redhat.com> References: <1413357930-45302-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1413357930-45302-1-git-send-email-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: rusty@rustcorp.com.au, mst@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: davem@davemloft.net, eric.dumazet@gmail.com List-Id: virtualization@lists.linuxfoundation.org Accumulate the sent packets and sent bytes in local variables and perform a single u64_stats_update_begin/end() after. Cc: Rusty Russell Cc: Michael S. Tsirkin Signed-off-by: Jason Wang --- drivers/net/virtio_net.c | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 3d0ce44..a4d56b8 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -833,17 +833,21 @@ static void free_old_xmit_skbs(struct send_queue *sq) unsigned int len; struct virtnet_info *vi = sq->vq->vdev->priv; struct virtnet_stats *stats = this_cpu_ptr(vi->stats); + u64 tx_bytes = 0, tx_packets = 0; while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { pr_debug("Sent skb %p\n", skb); - u64_stats_update_begin(&stats->tx_syncp); - stats->tx_bytes += skb->len; - stats->tx_packets++; - u64_stats_update_end(&stats->tx_syncp); + tx_bytes += skb->len; + tx_packets++; dev_kfree_skb_any(skb); } + + u64_stats_update_begin(&stats->tx_syncp); + stats->tx_bytes += tx_bytes; + stats->tx_packets =+ tx_packets; + u64_stats_update_end(&stats->tx_syncp); } static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) -- 1.7.1