From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751924AbaJOJeN (ORCPT ); Wed, 15 Oct 2014 05:34:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37338 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbaJOJeL (ORCPT ); Wed, 15 Oct 2014 05:34:11 -0400 Date: Wed, 15 Oct 2014 12:37:39 +0300 From: "Michael S. Tsirkin" To: Jason Wang Cc: rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, davem@davemloft.net, eric.dumazet@gmail.com Subject: Re: [RFC PATCH net-next 3/6] virtio-net: small optimization on free_old_xmit_skbs() Message-ID: <20141015093739.GC25776@redhat.com> References: <1413357930-45302-1-git-send-email-jasowang@redhat.com> <1413357930-45302-4-git-send-email-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413357930-45302-4-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 15, 2014 at 03:25:27PM +0800, Jason Wang wrote: > 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 Not sure how much it's worth but since Eric suggested it ... Acked-by: Michael S. Tsirkin > --- > 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