From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <konstantin.ananyev@intel.com>
Received: from mga09.intel.com (mga09.intel.com [134.134.136.24])
 by dpdk.org (Postfix) with ESMTP id 8E829159
 for <dev@dpdk.org>; Mon,  7 Apr 2014 10:53:13 +0200 (CEST)
Received: from orsmga001.jf.intel.com ([10.7.209.18])
 by orsmga102.jf.intel.com with ESMTP; 07 Apr 2014 01:49:20 -0700
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="4.97,808,1389772800"; d="scan'208";a="488494857"
Received: from irsmsx103.ger.corp.intel.com ([163.33.3.157])
 by orsmga001.jf.intel.com with ESMTP; 07 Apr 2014 01:54:01 -0700
Received: from irsmsx105.ger.corp.intel.com ([169.254.7.78]) by
 IRSMSX103.ger.corp.intel.com ([163.33.3.157]) with mapi id 14.03.0123.003;
 Mon, 7 Apr 2014 09:53:53 +0100
From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: "dev@dpdk.org" <dev@dpdk.org>
Thread-Topic: [dpdk-dev] rte_pktmbuf_alloc fails
Thread-Index: AQHPTZrHVVc8358MfkSbsYwzq1Jn0pr8lhqAgAkjVwCAACCCgA==
Date: Mon, 7 Apr 2014 08:53:52 +0000
Message-ID: <2601191342CEEE43887BDE71AB9772580EF94DE9@IRSMSX105.ger.corp.intel.com>
References: <CA+Typ9mJRUhSbOME=r3KFADxykKYN8snVAZ1JUEf8ohXbz-W7w@mail.gmail.com>
 <CA+Typ9kU8bPfT-9Be9O6uRAK-YWyJYAiMbtoCtbvXy4jQM-nJA@mail.gmail.com>
 <4032649.DyNZWczOjm@platinum>
In-Reply-To: <4032649.DyNZWczOjm@platinum>
Accept-Language: en-IE, en-US
Content-Language: en-US
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
x-originating-ip: [163.33.239.182]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Subject: Re: [dpdk-dev] rte_pktmbuf_alloc fails
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches and discussions about DPDK <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: Mon, 07 Apr 2014 08:53:14 -0000

Hi,
Yep indeed, there is a bug in eth_pcap_tx() that can cause mbuf corruption.
I think it should be something like that instead:

--- a/lib/librte_pmd_pcap/rte_eth_pcap.c
+++ b/lib/librte_pmd_pcap/rte_eth_pcap.c
@@ -205,8 +205,9 @@ eth_pcap_tx(void *queue,
                mbuf =3D bufs[i];
                ret =3D pcap_sendpacket(tx_queue->pcap, (u_char*) mbuf->pkt=
.data,
                                mbuf->pkt.data_len);
-               if(likely(!ret))
-                       num_tx++;
+               if(unlikely(ret !=3D 0))
+                       break;
+               num_tx++;
                rte_pktmbuf_free(mbuf);
        }

Thanks
Konstantin

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Olivier MATZ
Sent: Monday, April 07, 2014 8:27 AM
To: dev@dpdk.org
Cc: Meir Tseitlin
Subject: Re: [dpdk-dev] rte_pktmbuf_alloc fails

Hi Meir,

On Tuesday, April 01, 2014 02:53:47 PM Meir Tseitlin wrote:
> I think I found the problem - it was solved by manually calling=20
> rte_pktmbuf_free for each packet.
> It seems that rte_pktmbuf_free is not automatically called from within=20
> rte_eth_tx_burst if packets are sent to pcap device.

By looking at the eth_pcap_tx(pkts, nb_pkts) function, I think it may not w=
ork properly. I think it should return nb_pkts instead of num_tx. Indeed, i=
f
pcap_sendpacket() fails -- I don't know in which case it can occur -- the f=
unction will return a number lower than nb_pkts, causing a caller like
l2fwd_send_burst() to free some mbufs. But all mbufs are already freed by e=
th_pcap_tx().

I don't know if it's related to your problem but it may help.

Regards,
Olivier