From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F635C41514 for ; Thu, 22 Aug 2019 12:48:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15E562070B for ; Thu, 22 Aug 2019 12:48:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732590AbfHVMsn (ORCPT ); Thu, 22 Aug 2019 08:48:43 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:56072 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388015AbfHVMsl (ORCPT ); Thu, 22 Aug 2019 08:48:41 -0400 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 86BBDB07C253D1E9F21B; Thu, 22 Aug 2019 20:48:27 +0800 (CST) Received: from [127.0.0.1] (10.133.208.128) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.439.0; Thu, 22 Aug 2019 20:48:24 +0800 Subject: Re: [Virtio-fs] [QUESTION] A performance problem for buffer write compared with 9p To: Miklos Szeredi References: <5abd7616-5351-761c-0c14-21d511251006@huawei.com> <20190820091650.GE9855@stefanha-x1.localdomain> <20190821160551.GD9095@stefanha-x1.localdomain> <954b5f8a-4007-f29c-f38e-dd5585879541@huawei.com> CC: Stefan Hajnoczi , , "virtio-fs@redhat.com" , Miklos Szeredi From: wangyan Message-ID: <0e8090c7-0c7c-bcbe-af75-33054d3a3efb@huawei.com> Date: Thu, 22 Aug 2019 20:48:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.133.208.128] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2019/8/22 19:43, Miklos Szeredi wrote: > On Thu, Aug 22, 2019 at 2:59 AM wangyan wrote: >> I will test it when I get the patch, and post the compared result with >> 9p. > > Could you please try the attached patch? My guess is that it should > improve the performance, perhaps by a big margin. > > Further improvement is possible by eliminating page copies, but that > is less trivial. > > Thanks, > Miklos > Using the same test model. And the test result is: 1. Latency virtiofs: avg-lat is 15.40 usec, bigger than before(6.64 usec). 4K: (g=0): rw=write, bs=4K-4K/4K-4K/4K-4K, ioengine=psync, iodepth=1 fio-2.13 Starting 1 process Jobs: 1 (f=1): [W(1)] [100.0% done] [0KB/142.4MB/0KB /s] [0/36.5K/0 iops] [eta 00m:00s] 4K: (groupid=0, jobs=1): err= 0: pid=5528: Thu Aug 22 20:39:07 2019 write: io=6633.2MB, bw=226404KB/s, iops=56600, runt= 30001msec clat (usec): min=2, max=40403, avg=14.77, stdev=33.71 lat (usec): min=3, max=40404, avg=15.40, stdev=33.74 2. Bandwidth virtiofs: bandwidth is 280840KB/s, lower than before(691894KB/s). 1M: (g=0): rw=write, bs=1M-1M/1M-1M/1M-1M, ioengine=psync, iodepth=1 fio-2.13 Starting 1 process Jobs: 1 (f=1): [f(1)] [100.0% done] [0KB/29755KB/0KB /s] [0/29/0 iops] [eta 00m:00s] 1M: (groupid=0, jobs=1): err= 0: pid=5550: Thu Aug 22 20:41:28 2019 write: io=8228.0MB, bw=280840KB/s, iops=274, runt= 30001msec clat (usec): min=362, max=11038, avg=3571.33, stdev=1062.72 lat (usec): min=411, max=11093, avg=3628.39, stdev=1064.53 According to the result, the patch doesn't work and make it worse than before.