From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Coquelin Subject: Re: [PATCH] net/virtio: fix wrong TX pkt length stats Date: Fri, 13 Oct 2017 12:06:11 +0200 Message-ID: References: <20171011043935.16813-1-zhiyong.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: yliu@fridaylinux.org, jianfeng.tan@intel.com To: Zhiyong Yang , dev@dpdk.org Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 723381B663 for ; Fri, 13 Oct 2017 12:06:16 +0200 (CEST) In-Reply-To: <20171011043935.16813-1-zhiyong.yang@intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Zhiyong, On 10/11/2017 06:39 AM, Zhiyong Yang wrote: > In the function virtqueue_enqueue_xmit(), when can_push == 1 is true, > vtnet_hdr_size is added to pkt_len by calling rte_pktmbuf_prepend. > So, virtio header len should be subtracted before calling stats > function. > > Fixes: 58169a9c8153 ("net/virtio: support Tx checksum offload") > > Signed-off-by: Zhiyong Yang > --- > drivers/net/virtio/virtio_rxtx.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c > index 609b4138a..bf14f9a99 100644 > --- a/drivers/net/virtio/virtio_rxtx.c > +++ b/drivers/net/virtio/virtio_rxtx.c > @@ -1079,6 +1079,12 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts) > /* Enqueue Packet buffers */ > virtqueue_enqueue_xmit(txvq, txm, slots, use_indirect, can_push); > > + /* In function virtqueue_enqueue_xmit(), when can_push == 1 > + * is true, vtnet_hdr_size is added to pkt_len of mbuf. So, it > + * should be subtracted before calling stats function. > + */ > + if (can_push == 1) > + txm->pkt_len -= txvq->vq->hw->vtnet_hdr_size; > txvq->stats.bytes += txm->pkt_len; I acknowledge the problem, but I don't like modifying pkt_len. This is not the case currently, but in case we want to do something with the mbuf later in virtio_xmit_cleanup(), it could be good to have the real length there. What about: if (can_push == 1) txvq->stats.bytes += txm->pkt_len - txvq->vq->hw->vtnet_hdr_size; else txvq->stats.bytes += txm->pkt_len; Thanks, Maxime > virtio_update_packet_stats(&txvq->stats, txm); > } >