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 E5F8AC83F2C for ; Mon, 4 Sep 2023 06:08:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343510AbjIDGIt (ORCPT ); Mon, 4 Sep 2023 02:08:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232856AbjIDGIs (ORCPT ); Mon, 4 Sep 2023 02:08:48 -0400 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61EA9E1 for ; Sun, 3 Sep 2023 23:08:45 -0700 (PDT) Received: from cwcc.thunk.org (pool-173-48-116-73.bstnma.fios.verizon.net [173.48.116.73]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 38468K8g000566 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 4 Sep 2023 02:08:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1693807702; bh=8FOK8ZwU2F8j90ITve4Gg0SpbomBS5ivcppkFy7L10g=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=ckk+xfVU7q1ex6OaN64cK+9IOqiaR1Fw26OBXcQdwH9PjxiQW/dnqWHmG61gCAEfO 5H5triWso75mUWwksQsEv1i+nrG7D5gSNDiQxM1wmmWUBdWrlgz2nRi4iohcrvxw0Y CqjO1XLpVdABiqkz9SAB9QSxVSul+Jrw97n2XvPjhoGWHLwGzuph093J1JGtiALInk 5M1L6fHCEOVJ1fnTe/Fck4EDOrur4ZovJfw3yqlALgcB1tyoGiXByJBBo2CVXoZok3 c+JkW/0tDICLVZFl/VcJdA9tWnWWjFyaC0MmmPesP/qsDYpevdsVn6F0Hd+tUyG3Ms M6tVJ0/BhiiBQ== Received: by cwcc.thunk.org (Postfix, from userid 15806) id E032C15C023F; Mon, 4 Sep 2023 02:08:19 -0400 (EDT) Date: Mon, 4 Sep 2023 02:08:19 -0400 From: "Theodore Ts'o" To: Zorro Lang Cc: linux-ext4@vger.kernel.org, fstests@vger.kernel.org, regressions@lists.linux.dev, Matthew Wilcox , Andrew Morton Subject: Re: [fstests generic/388, 455, 475, 482 ...] Ext4 journal recovery test fails Message-ID: <20230904060819.GB701295@mit.edu> References: <20230903120001.qjv5uva2zaqthgk2@zlang-mailbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org #regzbot introduced: 8147c4c4546f9f05ef03bb839b741473b28bb560 ^ OK, I've isolated the regression of generic/455 failing with ext4/1k to this commit, which came in via the mm tree. Nothing seems *obviously* wrong, but I'm not sure if there are any differences in the semantics of the new folio functions such as kmap_local_folio, offset_in_folio, set_folio_bh() which might be making a difference. Using kvm-xfstests[1] I bisected this via the command: % install-kconfig ; kbuild ; kvm-xfstests -c ext4/1k -C 10 generic/455 [1] https://github.com/tytso/xfstests-bld/blob/master/Documentation/kvm-quickstart.md And the bisection pointed me at this commit: commit 8147c4c4546f9f05ef03bb839b741473b28bb560 (refs/bisect/bad) Author: Matthew Wilcox (Oracle) AuthorDate: Thu Jul 13 04:55:11 2023 +0100 Commit: Andrew Morton CommitDate: Fri Aug 18 10:12:30 2023 -0700 jbd2: use a folio in jbd2_journal_write_metadata_buffer() During the bisection, I treated a commit with 3+ failures as "bad", and 0-2 commits as "good". Running generic/455 50 times to get a sense of the failure, with the first bad commit (8147c4c4546f), I got: ext4/1k: 50 tests, 21 failures, 223 seconds Flaky: generic/455: 42% (21/50) Totals: 50 tests, 0 skipped, 21 failures, 0 errors, 223s While with the immediately preceding commit (07811230c3cd), I got: ext4/1k: 50 tests, 4 failures, 235 seconds Flaky: generic/455: 8% (4/50) Totals: 50 tests, 0 skipped, 4 failures, 0 errors, 235s Comparing these two commits (8147c4c4546f vs 07811230c3cd) using the ext4 with a 4k block size, I get: ext4/4k: 50 tests, 2 failures, 365 seconds Flaky: generic/455: 4% (2/50) Totals: 50 tests, 0 skipped, 2 failures, 0 errors, 365s vs ext4/4k: 50 tests, 2 failures, 349 seconds Flaky: generic/455: 4% (2/50) Totals: 50 tests, 0 skipped, 2 failures, 0 errors, 349s So issue seems to be specifically with a sub-page size block size, since ext4/4k doesn't show any issues, while ext4/1k does. - Ted