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 770D7C433EF for ; Tue, 10 May 2022 03:42:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E8BB36B0072; Mon, 9 May 2022 23:42:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E3AB86B0073; Mon, 9 May 2022 23:42:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CDB526B0074; Mon, 9 May 2022 23:42:07 -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 BE6D36B0072 for ; Mon, 9 May 2022 23:42:07 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id 95FBE80B4C for ; Tue, 10 May 2022 03:42:07 +0000 (UTC) X-FDA: 79448435094.10.07DC5B5 Received: from p3plwbeout26-02.prod.phx3.secureserver.net (p3plsmtp26-02-2.prod.phx3.secureserver.net [216.69.139.26]) by imf09.hostedemail.com (Postfix) with ESMTP id 4EBEE140069 for ; Tue, 10 May 2022 03:41:59 +0000 (UTC) Received: from mailex.mailcore.me ([94.136.40.145]) by :WBEOUT: with ESMTP id oGlAnGrdYFHlsoGlBn8bBN; Mon, 09 May 2022 20:42:05 -0700 X-CMAE-Analysis: v=2.4 cv=QsubYX+d c=1 sm=1 tr=0 ts=6279df0d a=7e6w4QD8YWtpVJ/7+iiidw==:117 a=84ok6UeoqCVsigPHarzEiQ==:17 a=ggZhUymU-5wA:10 a=IkcTkHD0fZMA:10 a=oZkIemNP1mAA:10 a=VwQbUJbxAAAA:8 a=pGLkceISAAAA:8 a=JfrnYn6hAAAA:8 a=c8wRBholBsc881OVBegA:9 a=QEXdDO2ut3YA:10 a=kzUPhV2tFCwA:10 a=1LVkccGuNtIA:10 a=AjGcO6oz07-iQ99wixmX:22 a=1CNFftbPRP8L7MoqJWF3:22 X-SECURESERVER-ACCT: phillip@squashfs.org.uk X-SID: oGlAnGrdYFHls Received: from 82-69-79-175.dsl.in-addr.zen.co.uk ([82.69.79.175] helo=[192.168.178.33]) by smtp02.mailcore.me with esmtpa (Exim 4.94.2) (envelope-from ) id 1noGlA-00082F-0Q; Tue, 10 May 2022 04:42:04 +0100 Message-ID: Date: Tue, 10 May 2022 04:41:58 +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 From: Phillip Lougher To: Matthew Wilcox Cc: Xiongwei Song , Zheng Liang , Zhang Yi , Hou Tao , Miao Xie , Andrew Morton , Linus Torvalds , Hsin-Yi Wang , "Song, Xiongwei" , "linux-mm@kvack.org" , "squashfs-devel@lists.sourceforge.net" , open list References: <13af40a9-6b60-6875-8326-0827e34182d5@squashfs.org.uk> <1dff431e-f51d-edb0-5abc-353ceeef50ed@squashfs.org.uk> In-Reply-To: <1dff431e-f51d-edb0-5abc-353ceeef50ed@squashfs.org.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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: MS4xfOC94afXY1Q6aczlu29CH+n1MHZSmHjqm5Izo+3TTEfLxLeUbrnxIFwiXKj8gXuUZHUuxDqPt60XBjKF0HQ9tuI2TpW7VeDp/9l/YMhw6AxRbdLeyBgX ynDWQY5qoKoCGs/NbddE7dHm14y9JYwdSZMoMDosHss0x8HlDkXFFpI799aLwnpKl0IWpCx8eVJPubEvDauoLCxwFDsQKJ/Bpl8= X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 4EBEE140069 X-Stat-Signature: 44yih3wi7kb3the76rsr3xuzptui5fqk Authentication-Results: imf09.hostedemail.com; dkim=none; dmarc=none; spf=none (imf09.hostedemail.com: domain of phillip@squashfs.org.uk has no SPF policy when checking 216.69.139.26) smtp.mailfrom=phillip@squashfs.org.uk X-HE-Tag: 1652154119-801184 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 10/05/2022 04:20, Phillip Lougher wrote: > On 10/05/2022 03:35, Matthew Wilcox wrote: >> On Tue, May 10, 2022 at 02:11:41AM +0100, Phillip Lougher wrote: >>> 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. >> >> I think you mean 'prerogative'.  And, no, your filesystem is not your >> little fiefdom, it's part of a collaborative effort. >> > > This isn't a spelling contest, and if that's the best you can do you > have already failed. > > Be carefull here also, I have been maintainer of Squashfs for 20 years, > and was kernel maintainer for both Ubuntu and Redhat for 10 years, and > so I am experienced member of the community. > > You reply is bordering on offensive and arrogant, especially considering > it is unwarranted.  I did not set out to offend you, and I don't > appreciate it. > > About 8 years ago I decided to refrain from active involvement in the > kernel community, because I decided the level of discourse was > disgusting, and I had enough of it. > > I poped up now to defend my approval of the Huawei patch.  I am *quite* > happy not to have any more involvement until necessary. > > So having said what I want to say, I will leave it at that. You have > just proved why I have minimised my involvement. > > No doubt you'll throw your toys out the pram, but, I'm no > longer listening so don't bother. > > >>> That patch (by Huawei) fixes the performance regression in Squashfs >>> by disabling readahead, and it is good workaround until something >>> better. >> >> You *didn't even report the problem to me*.  How can it be fixed if I'm >> not aware of it? Despite having been insulted, I have done your homework for you. This is where the problem was raised last year, with you directly emailed. https://lore.kernel.org/all/CAJMQK-g9G6KQmH-V=BRGX0swZji9Wxe_2c7ht-MMAapdFy2pXw@mail.gmail.com/T/ >> > > There was a email discussion last year, which I responded to, and got > ignored.  I will find it out tomorrow, perhaps.  But I will probably > not bother, because life is too short. > Afterwards you started a thread on "Readahead for compressed data", which I responded to. https://lore.kernel.org/all/YXHK5HrQpJu9oy8w@casper.infradead.org/T/ > Cheers > > Phillip