From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <alex@weka.io>
Received: from mail-lb0-f176.google.com (mail-lb0-f176.google.com
 [209.85.217.176]) by dpdk.org (Postfix) with ESMTP id 788BE2E8A
 for <dev@dpdk.org>; Tue,  7 Oct 2014 17:44:26 +0200 (CEST)
Received: by mail-lb0-f176.google.com with SMTP id p9so6319297lbv.21
 for <dev@dpdk.org>; Tue, 07 Oct 2014 08:51:39 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20130820;
 h=x-gm-message-state:mime-version:in-reply-to:references:date
 :message-id:subject:from:to:cc:content-type;
 bh=M8hrSwgg/+XLfvtJA247yRIOf1tHbny+5rqlrH3rNms=;
 b=JurD9XgQ703qWqlIEMo36zrC0aYUTrIa/h6vRdKGSzTr9QcbpUGyM0FcMmW0Sdf1Xb
 aqoLWT0WwJuZXWDGosftgE2K2Q8BK63ILf1dgOgWlmZNrkRPkaJMhXOs/GqSOpqzr49d
 SiZIuVWh9iU1j561/+vPs4Z+6eKvDxduOvI+JzjDJpWPiwiq3oL/Gcdm2Ta3dzfVFU9e
 i8u/k1HuSDUV5ihcueFJOIEOmvE7seCNu5xJAuP7HIBf2JgMMXB98OsL3MOZKvWBkbz1
 KISet4iVudBirJvwd9kwsFHrJL+Wia+KjTwkzvnX1Y2EZ29JkBdSk3/xql0npBX0go1y
 0YXA==
X-Gm-Message-State: ALoCoQk44a8y4a8+8K5hzZfBZZj00gxhm5mKmrX/UZfBluWYDOeik18l+v1K5uLfCYlGOiLpM25o
MIME-Version: 1.0
X-Received: by 10.112.198.74 with SMTP id ja10mr4879394lbc.14.1412697099477;
 Tue, 07 Oct 2014 08:51:39 -0700 (PDT)
Received: by 10.25.136.198 with HTTP; Tue, 7 Oct 2014 08:51:39 -0700 (PDT)
In-Reply-To: <2601191342CEEE43887BDE71AB97725821391089@IRSMSX105.ger.corp.intel.com>
References: <CAKfHP0XoA2jxmR7j0SAT_gWMnS+o6HCTB1-Gj0v4NjL27hQJvg@mail.gmail.com>
 <2601191342CEEE43887BDE71AB97725821391089@IRSMSX105.ger.corp.intel.com>
Date: Tue, 7 Oct 2014 18:51:39 +0300
Message-ID: <CAKfHP0X=7_gXDJ-cNJgLs6NUF8pZLtxUZvskY4KdeMsBV=U=Qg@mail.gmail.com>
From: Alex Markuze <alex@weka.io>
To: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
Content-Type: text/plain; charset=UTF-8
X-Content-Filtered-By: Mailman/MimeDel 2.1.15
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] Aligned RX data.
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: Tue, 07 Oct 2014 15:44:26 -0000

RTE_PKTMBUF_HEADROOM defines the headroom this would be true only if the
buff_start was aligned to 512 which is not.

On Tue, Oct 7, 2014 at 1:05 PM, Ananyev, Konstantin <
konstantin.ananyev@intel.com> wrote:

>
>
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Alex Markuze
> > Sent: Tuesday, October 07, 2014 10:40 AM
> > To: dev@dpdk.org
> > Subject: [dpdk-dev] Aligned RX data.
> >
> > Hi , I'm trying to receive aligned packets from the wire.
> > Meaning that for all received packets the pkt.data is always aligned to
> > (512 -H).
> >
> > Looking at the pmds of ixgbe/vmxnet I see that the pmds call
> > __rte_mbuf_raw_alloc and set the rx descriptor with a
> > RTE_MBUF_DATA_DMA_ADDR_DEFAULT
> > Instead of the more appropriate RTE_MBUF_DATA_DMA_ADDR.
> >
> > Do I need to modify each pmd I'm using to be able to receive aligned
> data?
>
> Make sure that your all your mbufs are aligned by 512 and set in your
> config RTE_PKTMBUF_HEADROOM=512-H?
>
>
> > Or have I missed something?
> >
> > Thanks
>