From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f44.google.com (mail-oa1-f44.google.com [209.85.160.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4AE5B1C34 for ; Tue, 20 Sep 2022 14:00:12 +0000 (UTC) Received: by mail-oa1-f44.google.com with SMTP id 586e51a60fabf-1274ec87ad5so4398076fac.0 for ; Tue, 20 Sep 2022 07:00:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date; bh=anwJ1q9b14QesSLm4IQZ3eD0Se0ge7to/g7pHbX3jG0=; b=bjlAlEIklUV7hPttdA8fDtvgyEyudwFcvTMbEssKiC6eBOZ2O2xFGl6XCcfc1SRiIE P/HW32nak3/AIw3q5NBSb9foiDz5+hzuTrEbGwyWvDrVar82JqUksGtwB9Wj6YVnX5ON RESLXA9eGCW8TdchEApJwPj07cv5HWqFSngD1AYH4BEJAVWe/BTDL/N7y9XqF8vbEg/A LBJikXoE9bT7BEaOWOLwWt52owdDJjZr8s2DsRTuc7OwUSokcsYM4+onJnfGO0sEfb4r NVIXIqtqiYYKv4ow15IcC2xT7DYCohO9dGIrJb9rr1BrRsBURg8/M7aBsepO1/bcxuRm lWTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date; bh=anwJ1q9b14QesSLm4IQZ3eD0Se0ge7to/g7pHbX3jG0=; b=pqMkMr44o9ZF4PUXHXwGkU6T5QfFkk4A6NBoY4wfEg2jUbuLxJQQf4mlNLCRWfH78R o8FRQ5JciLSwAckoWt/U/W4lQmWb+pEX6IZ4X/p2h3ruqwBWBEtZyA7zhm1XdF1iBn5H zvPn6O4idD0E/jmXYy8F1IEUYIocg1Bz1E3+I6gxcDGMnJcYL5HZ9gkXdwAjCrEk+p7y zjVyHzpK/GcEM2v0+Vql9qY2TmW3nGdViJXr5ImhA2LF6BhrcGAo62nuxjlStANvgwT1 53jqkP2u/VDBCeEcbHItw8ahdV5JHIAf2eYbIJ2dmz93Xq+/w7OvIbqd4v62Qo3CJOqX 9tUw== X-Gm-Message-State: ACrzQf2NetnODR59kq2W2dDFq9rLXElm+uWbxOj8oB+y18NtYiskEAnJ qK2iFKu5mx/Nr2ufF7ghjRy/GZ+t1nm8yU4i9ZU= X-Google-Smtp-Source: AMsMyM7M1YKMioaUgRWcbL23K4TaHKNh67DDfmsw8bUBSbp1bz0bgqIHBrVEMt51SFoqWOPTeCbJrP/ViUnRkbqN54M= X-Received: by 2002:a05:6870:c1c6:b0:12c:8311:8f3c with SMTP id i6-20020a056870c1c600b0012c83118f3cmr2206076oad.158.1663682411217; Tue, 20 Sep 2022 07:00:11 -0700 (PDT) Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <48bb6266-2d5c-ffcd-6982-4fd02bfdcfc3@leemhuis.info> In-Reply-To: <48bb6266-2d5c-ffcd-6982-4fd02bfdcfc3@leemhuis.info> From: hazem ahmed mohamed Date: Tue, 20 Sep 2022 14:59:34 +0100 Message-ID: Subject: Re: Ext4: Buffered random writes performance regression with dioread_nolock enabled To: Thorsten Leemhuis Cc: "linux-ext4@vger.kernel.org" , "tytso@mit.edu" , "adilger.kernel@dilger.ca" , "regressions@lists.linux.dev" , "stable@vger.kernel.org" , "Mohamed Abuelfotoh, Hazem" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Looks like I replied only on Thorsten insteading of replying to all so moving the discussion to the wider thread for better visibility. ---------- Forwarded message --------- From: Thorsten Leemhuis Date: Tue, 20 Sept 2022 at 14:31 Subject: Re: Ext4: Buffered random writes performance regression with dioread_nolock enabled To: hazem ahmed mohamed On 20.09.22 15:21, hazem ahmed mohamed wrote: > Thanks Thorsten, I am surprised that we merged this commit while it > has been showing regression since Day-0, unless there is an objection > I will submit a revert patch until we know what's going on here. Please keep replies online, then others can learn from the conversation and weight in. In this particular case I'd explained that a quick revert after all this time is likely a bad thing, as there is always a risk that is creates regressions of its own. :-/ Ciao, Thorsten > On 19.09.22 17:18, hazem ahmed mohamed wrote: > > > > I am sending this e-mail to report a performance regression that=E2=80= =99s > > caused by commit 244adf6426(ext4: make dioread_nolock the default) , I > > am listing the performance regression symptoms below & our analysis > > for the reported regression. > > FWIW, that patch went into v5.6-rc1~113^2~12 > > And BTW: it seems 0-day back then noticed that 244adf6426 caused a > performance regression as well, but it seems that was ignored: > https://lore.kernel.org/all/20201024120829.GK31092@shao2-debian/ > > Anyway, now to the main reason why I write this mail: > > [TLDR: I'm adding this regression report to the list of tracked > regressions; all text from me you find below is based on a few templates > paragraphs you might have encountered already already in similar form.] > > Thanks for the report. To be sure below issue doesn't fall through the > cracks unnoticed, I'm adding it to regzbot, my Linux kernel regression > tracking bot: > > #regzbot ^introduced 244adf6426 > #regzbot ignore-activity > > This isn't a regression? This issue or a fix for it are already > discussed somewhere else? It was fixed already? You want to clarify when > the regression started to happen? Or point out I got the title or > something else totally wrong? Then just reply -- ideally with also > telling regzbot about it, as explained here: > https://linux-regtracking.leemhuis.info/tracked-regression/ > > Reminder for developers: When fixing the issue, add 'Link:' tags > pointing to the report (the mail this one replies to), as explained for > in the Linux kernel's documentation; the webpage mention at the end of > the last para explains why this is important for tracked regressions. > > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) > > P.S.: As the Linux kernel's regression tracker I deal with a lot of > reports and sometimes miss something important when writing mails like > this. If that's the case here, don't hesitate to tell me in a public > reply, it's in everyone's interest to set the public record straight.