From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 10A4CA034E for ; Sun, 7 Jun 2020 17:21:25 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id A82621BFA4; Sun, 7 Jun 2020 17:21:23 +0200 (CEST) Received: from mail-wm1-f45.google.com (mail-wm1-f45.google.com [209.85.128.45]) by dpdk.org (Postfix) with ESMTP id 41DE11BEE3 for ; Sun, 7 Jun 2020 17:21:22 +0200 (CEST) Received: by mail-wm1-f45.google.com with SMTP id f185so13941668wmf.3 for ; Sun, 07 Jun 2020 08:21:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=nIxaBGKhjWMEosDGYJm9+zX48NCdP/sqC5nSVSvLnk4=; b=h2EEpiakn6mNllNcMLBKw7pRYWXutePmcMsLa5KFqdbWeh8QiFDDm9z3fnqi56vK3C CLBOLGRIOWcQqgBgNo0RazriyItDuFZks1/xX74mg9Wx47vAzmvqKmsXUd1OnAGRoli0 p0k/5L4seYwVd5sCd00m5umCrmzdFaVPQIridEtZxB/dYZXs0FPXcr+uiYNXDkBQF6mu dAbUUCmlE8tldYmY8/3veIDhvjit2GOcnkiJWKwndTBcRWq5L6HeIi+5VLAV5+2oWw2j u+2GgiSdiStoQxhWll+G7RqlHdG/NYR9xGRf05MSHKMdkYr0D725CygWxjkhWaTlvs9r ae6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=nIxaBGKhjWMEosDGYJm9+zX48NCdP/sqC5nSVSvLnk4=; b=LbWSYonYmUanPmT7OeI+Wtc93afESd4QKvVEv7O22ok9mRylFZbvBLrHtqHzS8Vkbv c+j1zrX/Z1k742v0fFT+mJZgLj784BxRUZphvtNldfTH3FO9PsT88uNm1fLREwUvZlLl ARqR70inTrsJRvreF1bOkreWwGXO/shBZw7B2PY7AdNC3+lQAc2PC7GVjNRF3zprOUC2 8ilEH55kOYBzu7id8nRhLSYqyRsq2Ul4VsTGSBcTpTBTeRa/EOlymbe5FaCxEeLPbNYj sl+2My/n3T2BSZ918kAONsbVWuyvgJQRl5+1Hs2nwVEgd8L7kq7YmZNvRHLJmpkZT9J2 GPiw== X-Gm-Message-State: AOAM5305dMTqllmSdECw1gwRyNcqXdtm4LZQOidkt70juG4rmshIh0AM tzANxtBJ2RIF0rG3ubz5nM4eJVmw9ZQ2xSNmTpFE4eem X-Google-Smtp-Source: ABdhPJwynU8Gw+pRYr5par82Q65EgqoTP4XIIv3BPEUglpwZYBDY+zbEphqyqdeJ4xpBkdp+SRjzg6lrm53QmJdBSpQ= X-Received: by 2002:a05:600c:2201:: with SMTP id z1mr11973703wml.70.1591543281767; Sun, 07 Jun 2020 08:21:21 -0700 (PDT) MIME-Version: 1.0 References: <504fcb6e5a12a03035e7b55507e7c279@therouter.net> <20200601091729.03ea9e50@hermes.lan> <7DA537F2-9887-4B0A-9249-064736E8A9AD@therouter.net> <5e91c3aa80e354241b03b908f5529d6b@therouter.net> In-Reply-To: <5e91c3aa80e354241b03b908f5529d6b@therouter.net> From: Cliff Burdick Date: Sun, 7 Jun 2020 08:21:10 -0700 Message-ID: To: Alex Kiselev Cc: Stephen Hemminger , users Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-users] segmention fault while accessing mbuf X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org Sender: "users" The mbuf pool said be configured to be the size of the largest packet you expect to receive. If you're getting packets longer than that, I would expect you to see problems. Same goes for transmitting; I believe it will just read past the end of the mbuf data. On Sun, Jun 7, 2020, 06:36 Alex Kiselev wrote: > On 2020-06-07 15:16, Cliff Burdick wrote: > > That shouldn't matter. The mbuf size is allocated when you create the > > mempool, and data_len/pkt_len are just to specify the size of the > > total packet and each segment. The underlying storage size is still > > the same. > > It does matter. I've done some tests and after > sending a few mbufs with data_len/pkt_len bigger than the size > of mbuf's underlying buffer the app stops sending/receiving packets. > The PMD apparently goes beyong the mbuf's buffer, that's why > I sill think that my question about the impact of using incorrect > data_len/pkt is valid. > > > > > Have you checked to see if it's potentially a hugepage issue? > > Please, explain. > > The app had been working two monghts before the crush > and the load was 3-4 gbit/s, so no, I don't think that > something is wrong with hugepages on that machine. > > > > > > On Sun, Jun 7, 2020, 02:59 Alex Kiselev wrote: > > > >> On 2020-06-07 04:41, Cliff Burdick wrote: > >>> I can't tell from your code, but you assigned nb_rx to the number > >> of > >>> packets received, but then used vec_size, which might be larger. > >> Does > >>> this happen if you use nb_rx in your loops? > >> > >> No, this doesn't happen. > >> I just skip the part of the code that translates nb_rx to vec_size, > >> since that code is double checked. > >> > >> My actual question now is about possible impact of using > >> incorrect values of mbuf's pkt_len and data_len fields. > >> > >>> > >>> On Sat, Jun 6, 2020 at 5:59 AM Alex Kiselev > >>> wrote: > >>> > >>>>> 1 =D0=B8=D1=8E=D0=BD=D1=8F 2020 =D0=B3., =D0=B2 19:17, Stephen Hemm= inger > >>>> =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0= =BB(=D0=B0): > >>>>> > >>>>> On Mon, 01 Jun 2020 15:24:25 +0200 > >>>>> Alex Kiselev wrote: > >>>>> > >>>>>> Hello, > >>>>>> > >>>>>> I've got a segmentation fault error in my data plane path. > >>>>>> I am pretty sure the code where the segfault happened is ok, > >>>>>> so my guess is that I somehow received a corrupted mbuf. > >>>>>> How could I troubleshoot this? Is there any way? > >>>>>> Is it possible that other threads of the application > >>>>>> corrupted that mbuf? > >>>>>> > >>>>>> I would really appriciate any advice. > >>>>>> Thanks. > >>>>>> > >>>>>> DPDK 18.11.3 > >>>>>> NIC: 82599ES > >>>>>> > >>>>>> Code: > >>>>>> > >>>>>> nb_rx =3D rte_eth_rx_burst(port_id, queue_id, pkts_burst, > >>>>>> MAX_PKT_BURST); > >>>>>> > >>>>>> ... > >>>>>> > >>>>>> for (i=3D0; i < vec_size; i++) { > >>>>>> rte_prefetch0(rte_pktmbuf_mtod(m_v[i], void *)); > >>>>>> > >>>>>> for (i=3D0; i < vec_size; i++) { > >>>>>> m =3D m_v[i]; > >>>>>> eth_hdr =3D rte_pktmbuf_mtod(m, struct ether_hdr *); > >>>>>> eth_type =3D rte_be_to_cpu_16(eth_hdr->ether_type); > >>>> <--- > >>>>>> Segmentation fault > >>>>>> ... > >>>>>> > >>>>>> #0 rte_arch_bswap16 (_x=3D >>>> memory > >>>>>> at address 0x4d80000000053010>) > >>>>> > >>>>> Build with as many of the debug options turned on in the DPDK > >>>> config, > >>>>> and build with EXTRA_CFLAGS of -g. > >>>> > >>>> Could using an incorrect (a very big one) value of mbuf pkt_len > >> and > >>>> data_len while transmitting cause mbuf corruption and following > >>>> segmentation fault on rx? >