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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91E3FC001DF for ; Tue, 1 Aug 2023 02:23:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229825AbjHACXI (ORCPT ); Mon, 31 Jul 2023 22:23:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbjHACXG (ORCPT ); Mon, 31 Jul 2023 22:23:06 -0400 Received: from out28-64.mail.aliyun.com (out28-64.mail.aliyun.com [115.124.28.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7515C10DD for ; Mon, 31 Jul 2023 19:23:04 -0700 (PDT) X-Alimail-AntiSpam: AC=CONTINUE;BC=0.4799461|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_social|0.778991-8.83197e-05-0.220921;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047193;MF=wangyugui@e16-tech.com;NM=1;PH=DS;RN=2;RT=2;SR=0;TI=SMTPD_---.U5FC74-_1690856573; Received: from 192.168.2.112(mailfrom:wangyugui@e16-tech.com fp:SMTPD_---.U5FC74-_1690856573) by smtp.aliyun-inc.com; Tue, 01 Aug 2023 10:22:57 +0800 Date: Tue, 01 Aug 2023 10:22:58 +0800 From: Wang Yugui To: Christoph Hellwig , linux-btrfs@vger.kernel.org Subject: Re: btrfs write-bandwidth performance regression of 6.5-rc4/rc3 In-Reply-To: <20230731152223.4EFB.409509F4@e16-tech.com> References: <20230731152223.4EFB.409509F4@e16-tech.com> Message-Id: <20230801102253.1AF4.409509F4@e16-tech.com> MIME-Version: 1.0 Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 8bit X-Mailer: Becky! ver. 2.81.04 [en] Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hi, > I noticed a btrfs write-bandwidth performance regression of 6.5-rc4/rc3 > with the compare to btrfs 6.4.0 > > test case: > disk: NVMe PCIe3 SSD *4 > btrfs: -m raid -d raid0 > fio -name write-bandwidth -rw=write -bs=1024Ki -size=32Gi -runtime=30 > -iodepth 1 -ioengine sync -zero_buffers=1 -direct=0 -end_fsync=1 -numjobs=4 > -directory=/mnt/test > > 6.5-rc4/rc3 > fio(-numjobs=4) WRITE: bw=1512MiB/s (1586MB/s) > but ¡®dd conv=fsync¡¯ works well, 2.1 GiB/s. > > 6.4.0 > fio(-numjobs=4) WRITE: bw=4147MiB/s (4349MB/s) > > 'git bisect' between 6.4 and 6.5 is yet not done. 'git bisect' show that this patch is the root cause of performance regression. e917ff56c8e7 :Christoph Hellwig: btrfs: determine synchronous writers from bio or writeback control The performance is still good when da023618076a :Christoph Hellwig: btrfs: submit IO synchronously for fast checksum implementations Best Regards Wang Yugui (wangyugui@e16-tech.com) 2023/08/01