From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <maxime.coquelin@redhat.com>
Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28])
by dpdk.org (Postfix) with ESMTP id F326E1B626
for <dev@dpdk.org>; Fri, 13 Oct 2017 14:47:40 +0200 (CEST)
Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com
[10.5.11.13])
(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
(No client certificate requested)
by mx1.redhat.com (Postfix) with ESMTPS id 20DAE60D1;
Fri, 13 Oct 2017 12:47:40 +0000 (UTC)
DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 20DAE60D1
Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com;
dmarc=none (p=none dis=none) header.from=redhat.com
Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com;
spf=fail smtp.mailfrom=maxime.coquelin@redhat.com
Received: from [10.36.112.24] (ovpn-112-24.ams2.redhat.com [10.36.112.24])
by smtp.corp.redhat.com (Postfix) with ESMTPS id 8CE4060A99;
Fri, 13 Oct 2017 12:47:38 +0000 (UTC)
To: "Yang, Zhiyong" <zhiyong.yang@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "yliu@fridaylinux.org" <yliu@fridaylinux.org>,
"Tan, Jianfeng" <jianfeng.tan@intel.com>
References: <20171011043935.16813-1-zhiyong.yang@intel.com>
<c268770f-625b-dafb-807d-c4d2b515ea95@redhat.com>
<E182254E98A5DA4EB1E657AC7CB9BD2A8AF4425D@BGSMSX101.gar.corp.intel.com>
From: Maxime Coquelin <maxime.coquelin@redhat.com>
Message-ID: <34d70b50-c35f-5eb2-7d30-19d35a1a43cb@redhat.com>
Date: Fri, 13 Oct 2017 14:47:36 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
Thunderbird/52.3.0
MIME-Version: 1.0
In-Reply-To: <E182254E98A5DA4EB1E657AC7CB9BD2A8AF4425D@BGSMSX101.gar.corp.intel.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16
(mx1.redhat.com [10.5.110.30]); Fri, 13 Oct 2017 12:47:40 +0000 (UTC)
Subject: Re: [dpdk-dev] [PATCH] net/virtio: fix wrong TX pkt length stats
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
<mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Fri, 13 Oct 2017 12:47:41 -0000
On 10/13/2017 02:44 PM, Yang, Zhiyong wrote:
> Hi Maxime,
>
>> -----Original Message-----
>> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
>> Sent: Friday, October 13, 2017 6:06 PM
>> To: Yang, Zhiyong <zhiyong.yang@intel.com>; dev@dpdk.org
>> Cc: yliu@fridaylinux.org; Tan, Jianfeng <jianfeng.tan@intel.com>
>> Subject: Re: [PATCH] net/virtio: fix wrong TX pkt length stats
>>
>> 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 <zhiyong.yang@intel.com>
>>> ---
>>> 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;
>
> I don't like modifying pkt_len, too.
> But We need to consider that some stats are updated in virtio_update_packet_stats()
> In this function, pkt_len will be used further.
Ha, good point!
I think we have no better way then:
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
> Thanks
> Zhiyong
>
>>
>> Thanks,
>> Maxime
>>
>>> virtio_update_packet_stats(&txvq->stats, txm);
>>> }
>>>