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 D4212C433EF for ; Tue, 10 May 2022 02:35:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 422C76B0074; Mon, 9 May 2022 22:35:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3ABBC6B0075; Mon, 9 May 2022 22:35:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 24BB46B0078; Mon, 9 May 2022 22:35:23 -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 129646B0074 for ; Mon, 9 May 2022 22:35:23 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id D116521451 for ; Tue, 10 May 2022 02:35:22 +0000 (UTC) X-FDA: 79448266884.24.BAEB8A1 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id 36C532008A for ; Tue, 10 May 2022 02:35:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=XUkwOFXROi4n/GY3pu0CZCq+Y5OOHTHprsmPZOti5h0=; b=oyTJezF1mulzIGpesv3Xts35aX cT7DAS1CfXz/yAS5QGy2DtKvenwygmXf45Q2RsS9IKvaPyjRHWkoc51bHqQeT2xMsVBuLltU5nhYU GqePNycjKjA+W6oFTp0uarIVOm11I8CvI7kTPz3Z5rMPo32NsOcB/10pv9LTv7bjI91cafrhM6IXW xnGH2Y1QxBLzgnh4Jheup5KIN30Ws94XadMotwhfAoi7YCtPUO4U8x2ycF0QQB3cX2KWTaiYIA1bM KRkMTA60sCoxUWGK0X7hPKnIyZod0WlRY3vr8TO5eKEPFRLe2rWCES/AYADa1TSfFehbBeZ6qFk4F 7Z29xspg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1noFiS-0041Os-2J; Tue, 10 May 2022 02:35:12 +0000 Date: Tue, 10 May 2022 03:35:12 +0100 From: Matthew Wilcox To: Phillip Lougher 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" Subject: Re: squashfs performance regression and readahea Message-ID: References: <13af40a9-6b60-6875-8326-0827e34182d5@squashfs.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <13af40a9-6b60-6875-8326-0827e34182d5@squashfs.org.uk> Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=oyTJezF1; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 36C532008A X-Stat-Signature: g45fz89khfd8f8icxesw7mbhdch7ycw1 X-HE-Tag: 1652150106-552153 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 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. > 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?