From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f170.google.com (mail-yw0-f170.google.com [209.85.161.170]) by dpdk.org (Postfix) with ESMTP id 48A3C37B1 for ; Mon, 26 Sep 2016 06:24:27 +0200 (CEST) Received: by mail-yw0-f170.google.com with SMTP id i129so150674305ywb.0 for ; Sun, 25 Sep 2016 21:24:27 -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=eADcwzGo3Sf3brd2ncm5Opn80AxD8r8QYBcMtxvv7ZU=; b=Kr4wtjQUsSZrEp0Fp67+a1Jf9ILNd2N5CjdXbkW5qNwo7vjDxAzKKqoM11ZHBDeYer ddYLYiKOIL5bsKIhJASSjbAnPu2CJDAMwVx/8IvgZIkQnphB8qTFbvLQYNm7qErPD6J3 JGDnT0abCm9ZWZ7EizTsQ6BHq/qlWxYP/46y0= 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=eADcwzGo3Sf3brd2ncm5Opn80AxD8r8QYBcMtxvv7ZU=; b=AY0bDwV1XFmQNZZC6LSqxDemReMlU2sZCSrYkiwnzBgLIV6IyebCyg4/Fu0pFbojcP UNtQHOHoyY0fVxZddre9VFabkaW9PVuCNH9KeFYBIz2TCJmtfYSDuo5iIzizbPsOgHAI ubOCz7eV4T7SNKRGoqaEhBfgtno68NZiOzpcyy3GsDb5eaeeXUrmVke52AJJFplew/mQ Dg6EZ4EALvzsFUOeQKTp7jX/y/n4+g9CnLH3i/MugnShbnKmDWgdqS5iRIHYdz970li5 PGxakfyeQM+/amyXFEk0P9QtBWg9qAQDocIcy6J13sZY+tVcJifNrnqpyOKyAlJukeQ+ QOSA== X-Gm-Message-State: AE9vXwP773cTa5plvfmqJ4hGm7UiD9OWtSVKZm224Y2LvgEmbwTFYM571Hc/GlsRQ0u1BVReZniEkjIax2UU05cX X-Received: by 10.13.223.22 with SMTP id i22mr17575737ywe.32.1474863866752; Sun, 25 Sep 2016 21:24:26 -0700 (PDT) MIME-Version: 1.0 Received: by 10.37.25.6 with HTTP; Sun, 25 Sep 2016 21:24:25 -0700 (PDT) In-Reply-To: <1536480.IYe8r5XoNN@xps13> References: <1471319402-112998-1-git-send-email-zhihong.wang@intel.com> <8F6C2BD409508844A0EFC19955BE09414E7B6204@SHSMSX103.ccr.corp.intel.com> <1536480.IYe8r5XoNN@xps13> From: Jianbo Liu Date: Mon, 26 Sep 2016 12:24:25 +0800 Message-ID: To: Thomas Monjalon Cc: dev@dpdk.org, "Wang, Zhihong" , Yuanhan Liu , Maxime Coquelin 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: Mon, 26 Sep 2016 04:24:27 -0000 Hi Thomas, On 23 September 2016 at 21:41, Thomas Monjalon wrote: > 2016-09-23 18:41, Jianbo Liu: >> On 23 September 2016 at 10:56, Wang, Zhihong wrote: >> ..... >> > This is expected because the 2nd patch is just a baseline and all optimization >> > patches are organized in the rest of this patch set. >> > >> > I think you can do bottleneck analysis on ARM to see what's slowing down the >> > perf, there might be some micro-arch complications there, mostly likely in >> > memcpy. >> > >> > Do you use glibc's memcpy? I suggest to hand-crafted it on your own. >> > >> > Could you publish the mrg_rxbuf=on data also? Since it's more widely used >> > in terms of spec integrity. >> > >> I don't think it will be helpful for you, considering the differences >> between x86 and arm. >> So please move on with this patchset... > > Jianbo, > I don't understand. > You said that the 2nd patch is a regression: > - volatile uint16_t last_used_idx; > + uint16_t last_used_idx; > No, I meant "vhost: rewrite enqueue". > And the overrall series lead to performance regression > for packets > 512 B, right? > But we don't know wether you have tested the v6 or not. Yes, I tested v6, and found performance regression for size >=512B. > > Zhihong talked about some improvements possible in rte_memcpy. > ARM64 is using libc memcpy in rte_memcpy. > > Now you seem to give up. > Does it mean you accept having a regression in 16.11 release? > Are you working on rte_memcpy? This patchset actually improves performance according to Zhihong's result on x86 platfrom. And I also get improvement as least with small-size packet on ARM. I don't want to give up, but I need more time to find out the reason for the regression. I think rte_memcpy definitely is one of the ways to improve performance, but it could be the reason?