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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32875C433F5 for ; Tue, 10 May 2022 01:11:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 481636B0072; Mon, 9 May 2022 21:11:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 457A26B0073; Mon, 9 May 2022 21:11:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2F8666B0074; Mon, 9 May 2022 21:11:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 1FC326B0072 for ; Mon, 9 May 2022 21:11:50 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id D6C7231511 for ; Tue, 10 May 2022 01:11:49 +0000 (UTC) X-FDA: 79448056338.13.A078180 Received: from p3plwbeout14-03.prod.phx3.secureserver.net (p3plsmtp14-03-2.prod.phx3.secureserver.net [173.201.192.186]) by imf19.hostedemail.com (Postfix) with ESMTP id 5DE9E1A0093 for ; Tue, 10 May 2022 01:11:41 +0000 (UTC) Received: from mailex.mailcore.me ([94.136.40.142]) by :WBEOUT: with ESMTP id oEPjnn772kAtDoEPjnkWEf; Mon, 09 May 2022 18:11:48 -0700 X-CMAE-Analysis: v=2.4 cv=b/Z3XvKx c=1 sm=1 tr=0 ts=6279bbd4 a=s1hRAmXuQnGNrIj+3lWWVA==:117 a=84ok6UeoqCVsigPHarzEiQ==:17 a=ggZhUymU-5wA:10 a=IkcTkHD0fZMA:10 a=oZkIemNP1mAA:10 a=fvODBAn_XVqumbcpjn4A:9 a=QEXdDO2ut3YA:10 X-SECURESERVER-ACCT: phillip@squashfs.org.uk X-SID: oEPjnn772kAtD Received: from 82-69-79-175.dsl.in-addr.zen.co.uk ([82.69.79.175] helo=[192.168.178.33]) by smtp01.mailcore.me with esmtpa (Exim 4.94.2) (envelope-from ) id 1noEPi-00077G-H2; Tue, 10 May 2022 02:11:46 +0100 Message-ID: <13af40a9-6b60-6875-8326-0827e34182d5@squashfs.org.uk> Date: Tue, 10 May 2022 02:11:41 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: squashfs performance regression and readahea To: Matthew Wilcox , Xiongwei Song , Zheng Liang , Zhang Yi , Hou Tao , Miao Xie , Andrew Morton , Linus Torvalds Cc: Hsin-Yi Wang , "Song, Xiongwei" , "linux-mm@kvack.org" , "squashfs-devel@lists.sourceforge.net" References: From: Phillip Lougher In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Mailcore-Auth: 439999529 X-Mailcore-Domain: 1394945 X-123-reg-Authenticated: phillip@squashfs.org.uk X-Originating-IP: 82.69.79.175 X-CMAE-Envelope: MS4xfEw6IlDEiA858ZeV/Eok+FNMzt5ouz7jj58wG8M/eWd4FRaghqd2OuvFHTLT30p+asA3AvkqZ+bmQmHH3mCZfWiKxyaCzr8BhxQjF7Rkgu9crtuHP6M7 O7OkqlIEMBxgivgh+AcPxp8lykM4qIQGi4B7cMvfkVZcWPxqbt5NlQ6CL4J7X/SFseE+7I4F+LoVkZQs5PmEqHnCJlKxX1qZ1C0= X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 5DE9E1A0093 Authentication-Results: imf19.hostedemail.com; dkim=none; spf=none (imf19.hostedemail.com: domain of phillip@squashfs.org.uk has no SPF policy when checking 173.201.192.186) smtp.mailfrom=phillip@squashfs.org.uk; dmarc=none X-Rspam-User: X-Stat-Signature: 5b5fxhwe676j5td1h3bxwcuwd8j4td96 X-HE-Tag: 1652145101-218483 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 09/05/2022 14:21, Matthew Wilcox wrote: > On Mon, May 09, 2022 at 08:43:45PM +0800, Xiongwei Song wrote: >> Hi Hsin-Yi and Matthew, >> >> With the patch from the attachment on linux 5.10, ran the command as I >> mentioned earlier, >> got the results below: >> 1:40.65 (1m + 40.65s) >> 1:10.12 >> 1:11.10 >> 1:11.47 >> 1:11.59 >> 1:11.94 >> 1:11.86 >> 1:12.04 >> 1:12.21 >> 1:12.06 >> >> The performance has improved obviously, but compared to linux 4.18, the >> performance is not so good. >> >> Moreover, I wanted to test on linux 5.18. But I think I should revert >> 9eec1d897139 ("squashfs: provide backing_dev_info in order to disable >> read-ahead"), >> right? Otherwise, the patch doesn't work? > > I've never seen patch 9eec1d897139 before. If you're going to point > out bugs in my code, at least have the decency to cc me on it. It > should never have gone in, and should be reverted so the problem can > be fixed properly. You are not in charge of what patches goes into Squashfs, that is my perogative as maintainer of Squashfs. That patch (by Huawei) fixes the performance regression in Squashfs by disabling readahead, and it is good workaround until something better. If the patch being worked-on now, once reviewed is acceptable, it can replace the current workaround, which will be reverted. Cheers Dr. Phillip Lougher -- Squashfs author and maintainer.