From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f49.google.com (mail-wm0-f49.google.com [74.125.82.49]) by dpdk.org (Postfix) with ESMTP id 40E88201 for ; Fri, 17 Feb 2017 14:51:58 +0100 (CET) Received: by mail-wm0-f49.google.com with SMTP id c85so15623964wmi.1 for ; Fri, 17 Feb 2017 05:51:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc:content-transfer-encoding; bh=f6byefgVUjVKRVTqqDkDKyxbC1mMXizziFmf5JhjpnE=; b=RnvMpV3DW85x+23nZ1a+E55dznjQ8ZioUXciVtrzOEl1R+PltvEXJHmF8lDC16bt1O oFPHZP88IC/lRMhJewIUGhPC0fYPvUVZKdwwCU1w5Ey7jhCM8D//tSeO5+ve4lX1fP3G WlK7D4j06sC2WK+W12LAvY4vT2S6qjNwtUv/J9aUzl+LnrE47ouf2yJWsJTgD2BAJIio eM+5esHtA7c0BslvGnfAHsw9YGPv59juMn2256Zt0ALuyKawtUfjKm3NQ//+0X+VLgRp 0ULkjZdpyA4dAgX1f5GGJDkfzioh8OP2YOv3YMcfdgUILcQc45i1ybOMjirhrkDqqrzR WG2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc:content-transfer-encoding; bh=f6byefgVUjVKRVTqqDkDKyxbC1mMXizziFmf5JhjpnE=; b=Ls5ZlQUmMwN0F0xrHQibzWgATat4vAYFY7TdWqPEHvxrphjUZRxX3Ywx8U9tQ3bzVu VhTmwMcYWlRF2X8m70hstUpxr09OQ71S/MuB2jcNdF7+VL2s3YCAuwl4Bvc15q4QM6vS OSH/okpXfAYPZ3ljMv4Ymwd5rA+kAgM9K/ToSUwpERagHB4Cm1mujqmPI57YoKV0JklP WdQ0JfYViXR6MvvLfxdPMrF0H7zLYiCor/u/K19khyLgoPQWNu/TSvJa5JEYTfLJcg2Z jOOTZKJkbPw4gFECCubS7BYD7k7NM2aYFhQbNNDxAoqyKo9bivisFTF+cg2gybkvyxhd 1uyg== X-Gm-Message-State: AMke39m0VdUayrZIPfbv06WPttjnbZMX6b1Uu5yJq9TTQaWcJ/haarRj0GlKFF0/vJ2WMrtIRbXuQAMzuIc0vA== X-Received: by 10.28.102.67 with SMTP id a64mr3863136wmc.140.1487339518017; Fri, 17 Feb 2017 05:51:58 -0800 (PST) MIME-Version: 1.0 Sender: jblunck@gmail.com Received: by 10.28.211.20 with HTTP; Fri, 17 Feb 2017 05:51:57 -0800 (PST) In-Reply-To: <20170217124954.GO23344@autoinstall.dev.6wind.com> References: <1485271173-13408-1-git-send-email-olivier.matz@6wind.com> <2601191342CEEE43887BDE71AB9772583F111A29@irsmsx105.ger.corp.intel.com> <20170216144807.7add2c71@platinum> <20170217115153.0afeb061@platinum> <20170217124954.GO23344@autoinstall.dev.6wind.com> From: Jan Blunck Date: Fri, 17 Feb 2017 14:51:57 +0100 X-Google-Sender-Auth: iBIRTN6VUW_9W3qHGvtMOTvM8YA Message-ID: To: =?UTF-8?Q?N=C3=A9lio_Laranjeiro?= Cc: Olivier Matz , "Ananyev, Konstantin" , "dev@dpdk.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] [RFC 0/8] mbuf: structure reorganization X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Feb 2017 13:51:58 -0000 On Fri, Feb 17, 2017 at 1:49 PM, N=C3=A9lio Laranjeiro wrote: > Hi Olivier, Jan, > > On Fri, Feb 17, 2017 at 11:51:53AM +0100, Olivier Matz wrote: >> Hi Jan, >> >> On Thu, 16 Feb 2017 18:26:39 +0100, Jan Blunck >> wrote: >> > >> > If we talk about setting the timestamp value in the RX path this >> > implicitly means software timestamps. Hardware timestamping usually >> > works by letting the hardware inject sync events for coarse time >> > tracking and additionally injecting fine granular per-packet ticks at >> > a specific offset in the packet. Out of performance reasons I don't >> > think it makes sense to extract this during the burst and write it >> > into the mbuf again. >> >> From what I've understand, at least it does not work like this for >> mellanox NICs: timestamp is a metadata attached to a rx packet. But >> maybe they (and other NIC vendors interrested in the feature) can >> confirm or not. > > Olivier is right, this timestamp information is returned by the hardware > as the other fields describing the Rx packet (length, RSS hash, checksum > ...). The PMD only copy it into the Mbuf. > Indeed, for Mellanox the timestamp is stored in the CQ entry. Solarflares write it relative to the packet header.