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 C39C6CD98F8 for ; Wed, 11 Oct 2023 07:53:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230005AbjJKHxn (ORCPT ); Wed, 11 Oct 2023 03:53:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229887AbjJKHxm (ORCPT ); Wed, 11 Oct 2023 03:53:42 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBF06D8 for ; Wed, 11 Oct 2023 00:53:40 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPS id 1E52CC433C7 for ; Wed, 11 Oct 2023 07:53:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697010820; bh=S5v0XFFqEChTCSPoUhbnCwjUaPS///XgaT1GXIn5KCE=; h=From:To:Subject:Date:In-Reply-To:References:From; b=IDuTNFwrT8SrQKkO6k2Y+uCCf9tW5bFqf2O76MKc0tCkrbVHSObizz2aZJEdGC4ze hDI5Qd1ClLwALSnnSIjZvEnDcZDudk5RJrP27rqrzA3nl/tVN3YA/HPB75RwqelUDf b50aliFMCWoGdqfatve8XAktnc48gNQmy5q6a2fELj9dfESm2QZze4Xg1noJ4LQIEb cpRN/lU0n3iyaaUAfC664gLEg6zsO7d4rXcS9UqniCgr5WVwBQG9nZ0UJhDwSRDATV g2nMBIsHjFs0UwXPm4HeYH3BeeO2J25djKslfvxuFszd4DZf8/Q+qH9Z/Q9oNK0MD8 9TmJ8BqieTVxA== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 0A2CBC53BD0; Wed, 11 Oct 2023 07:53:40 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-ext4@vger.kernel.org Subject: [Bug 217965] ext4(?) regression since 6.5.0 on sata hdd Date: Wed, 11 Oct 2023 07:53:39 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo fs_ext4@kernel-bugs.osdl.org X-Bugzilla-Product: File System X-Bugzilla-Component: ext4 X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ojaswin.mujoo@ibm.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: fs_ext4@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=3D217965 --- Comment #12 from Ojaswin Mujoo (ojaswin.mujoo@ibm.com) --- Hey Ivan,=20 so I used the kernel v6.6-rc1 and the same config you provided as well as w= ell as mounted an hdd on my VM. Then I followed the steps here build openwrt [1= ]. However, I'm still unable to replicate the 100% cpu utilization in a kworker/flush thread (I do get . Since you have the config options enabled and we didn't see them trigger any warning and the fact that we get back to normal after a few minutes indicat= es that its not a lockup/deadlock. We also see that on faster SSD we don't see this issue so this might even have something to do with a lot of IOs being queued up on the slower disk causing us to notice the delay. Maybe we are waiting a lot more on some spinlock that can explain the CPU utilization. Since I'm unable to replicate it, I'll have to request you for some more in= fo to get to the bottom of this. More specifically, can you kindly provide the following: For the kernel with this issue:=20 1. Replicate the 100% util in one terminal window. 2. Once the 100% util is hit, in another terminal run the following command: $ iostat -x /dev/ 2 (run this for 20 to 30 seconds)=20=20 $ perf record -ag sleep 20 $ echo l > /proc/sysrq_trigger $ uname -a 3. Repeat the above for a kernel where the issue is not seen.=20 Kindly share the sysrq back trace, iostat output, perf.data and the uname output for both the runs here so that I can take a closer look at what is causing the unusual utilization. [1] https://github.com/openwrt/openwrt#quickstart Regards, ojaswin --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=