From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f175.google.com (mail-yw0-f175.google.com [209.85.161.175]) by dpdk.org (Postfix) with ESMTP id EF7F3298F for ; Thu, 22 Sep 2016 07:47:46 +0200 (CEST) Received: by mail-yw0-f175.google.com with SMTP id t67so84053580ywg.3 for ; Wed, 21 Sep 2016 22:47:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=Bs6O7Mcql0c0gF5n1O2zhVfLhS0qejprC522qgUh8rA=; b=fOC+r2+vlZaMzPv4M5g4iYakwjQrldHjGPjsab3FZ0YDIoT2tNCjzC6x/vHfn+fyD+ cjlHUrONAQEZwTsvNAJu5tpPshlmrDAt5i2Ugh0V1/BfF2BfILRDqX2VuNy49nei8VMu ZaXeVZg+wKA8ZncIPUzwBev2VKYj9vJtBTvJg= 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:from:date :message-id:subject:to:cc; bh=Bs6O7Mcql0c0gF5n1O2zhVfLhS0qejprC522qgUh8rA=; b=Y8BiVuqK7u53R0MeJPBTOXVHKlci4QcDXrXSpG2CMt6lV7sRWwPNLAz5ZT0mVEaWw6 tZe/VlkWcTAB2t1C49PC8hE4ARHA8/HMZw1QzewzHVJd5t8SM3gva0xHqfemWIk6oPuj Cf6l478O1uAaJbzO5rpyzleCudHKU/QjWTeX/5wepUhQltR7ZMby8jg/80Qt7oMapqwd KVLZ05IyyzHrlze57rrUE2OSoy7lvTwjsBkIyUvbMnbHSeUOEjKhPzyl2E/KSnCgmm80 VE7DAeajgPpg+rpRRYZj32eybrCK1HuhMyvidUipbnWPNfjlB81r22ie/RBpokX3TEcT amHg== X-Gm-Message-State: AE9vXwOQI8sCGvgQbsv94t1EbRqdRDbMj5B1eWHpm0P0sk01yUsmxXo2iXGkRAd/Trq26Q+Lx6WwDcnl2ZO4HB/g X-Received: by 10.129.167.193 with SMTP id e184mr145898ywh.60.1474523266414; Wed, 21 Sep 2016 22:47:46 -0700 (PDT) MIME-Version: 1.0 Received: by 10.37.25.6 with HTTP; Wed, 21 Sep 2016 22:47:45 -0700 (PDT) In-Reply-To: <20160922022903.GJ23158@yliu-dev.sh.intel.com> References: <1471319402-112998-1-git-send-email-zhihong.wang@intel.com> <1471585430-125925-1-git-send-email-zhihong.wang@intel.com> <8F6C2BD409508844A0EFC19955BE09414E7B5581@SHSMSX103.ccr.corp.intel.com> <20160922022903.GJ23158@yliu-dev.sh.intel.com> From: Jianbo Liu Date: Thu, 22 Sep 2016 13:47:45 +0800 Message-ID: To: Yuanhan Liu Cc: "Wang, Zhihong" , Maxime Coquelin , "dev@dpdk.org" Content-Type: text/plain; charset=UTF-8 Subject: Re: [dpdk-dev] [PATCH v3 0/5] vhost: optimize enqueue X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Sep 2016 05:47:47 -0000 On 22 September 2016 at 10:29, Yuanhan Liu wrote: > On Wed, Sep 21, 2016 at 08:54:11PM +0800, Jianbo Liu wrote: >> >> > My setup consists of one host running a guest. >> >> > The guest generates as much 64bytes packets as possible using >> >> >> >> Have you tested with other different packet size? >> >> My testing shows that performance is dropping when packet size is more >> >> than 256. >> > >> > >> > Hi Jianbo, >> > >> > Thanks for reporting this. >> > >> > 1. Are you running the vector frontend with mrg_rxbuf=off? >> > Yes, my testing is mrg_rxbuf=off, but not vector frontend PMD. >> > 2. Could you please specify what CPU you're running? Is it Haswell >> > or Ivy Bridge? >> > It's an ARM server. >> > 3. How many percentage of drop are you seeing? The testing result: size (bytes) improvement (%) 64 3.92 128 11.51 256 24.16 512 -13.79 1024 -22.51 1500 -12.22 A correction is that performance is dropping if byte size is larger than 512. >> > >> > This is expected by me because I've already found the root cause and >> > the way to optimize it, but since it missed the v0 deadline and >> > requires changes in eal/memcpy, I postpone it to the next release. >> > >> > After the upcoming optimization the performance for packets larger >> > than 256 will be improved, and the new code will be much faster than >> > the current code. >> > >> >> Sorry, I tested on an ARM server, but I wonder if there is the same >> issue for x86 platform. > > Would you please provide more details? Say, answer the two left > questions from Zhihong? > > Thanks. > > --yliu