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 A64F0CA0FE0 for ; Thu, 31 Aug 2023 23:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347896AbjHaXfN (ORCPT ); Thu, 31 Aug 2023 19:35:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233190AbjHaXfM (ORCPT ); Thu, 31 Aug 2023 19:35:12 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53C5FE50 for ; Thu, 31 Aug 2023 16:35:09 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id d9443c01a7336-1c0bae4da38so9186275ad.0 for ; Thu, 31 Aug 2023 16:35:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1693524908; x=1694129708; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=SnTD/qfGQeY3JaNKKwV4/Zlh7IqE1aYYBA1ehh6D7Qc=; b=Y0xah0OfRT3anvwxi0YzK7gYSzbBAtkWqxKFSBAMbb1H0AjWDAszbBD3SZFWn++odw gsa6AzR9UByV4vJZez8+SV+ONhijVHqNbiqPH9qgPzkiQMKa/2O6vcp3FQwqBgsPmmkv B3IQMqhraeUWECAxKb2I+H8sXM+FHiTI3cIPpd85DODeUp9ooUh2kpnAI2IE4+205Eof Qg1xey4R3+3lMlJH2c8KAgkanLJ+0bcnBmFZ2EIJFIT6+rCMRZrKnnhmIhXIzS377jd/ tMwTeJMkB7zgbsEQR5wHPUsISJlC2y4+D+0xhz6xslqkSud/ujK0y0FmsmVfutEhHfLI rTYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693524908; x=1694129708; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=SnTD/qfGQeY3JaNKKwV4/Zlh7IqE1aYYBA1ehh6D7Qc=; b=Z6DEgWnWWJ+VV+H8ccCTlbsVmEyEXjnhB/CcIh/5k1k1expBHo429z4lCpdDV0Lpr6 J3bKKyuTuIlsfu4tpTuJtt0m1uLu0lvEFr6IO5KiDOjHSrrVTroEVNNbs4n/yFbsxo/e wYe//nopHE8f/yhAg0dZdgb/9k9LV4glZJZwFM7/DZvwY2E1QrUNX27vVETrdT3neX4f otl71vEidE6sbBd5JQX6bYm+rKSkDU+BrY+k+ncMFyAkH5HnWlfCx3kwPZQRRoIuhjjf 5hZ2ZItuLrbai5WD+fhnMQgk19bVgt3AwFLBWf9osYHDZMB/eOucengZl8a57LznOp8G wy2A== X-Gm-Message-State: AOJu0Yy1ixb//jMFrROSoQu/CGN4HSUoAB2KHzINQJd13qeqeTuJorri sp1gAXM93Pr/TL3r1T1HFKY= X-Google-Smtp-Source: AGHT+IGYqIzeQcTECd6RWQ3/nUs34nuB/uwnMzaLAFrYR0FQl+uuLqF7+fr+to3m67HnSu9xRiztrg== X-Received: by 2002:a17:902:ab54:b0:1b8:8682:62fb with SMTP id ij20-20020a170902ab5400b001b8868262fbmr1039627plb.4.1693524908500; Thu, 31 Aug 2023 16:35:08 -0700 (PDT) Received: from debian.me ([103.124.138.83]) by smtp.gmail.com with ESMTPSA id jj14-20020a170903048e00b001bde6fa0a39sm1749096plb.167.2023.08.31.16.35.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Aug 2023 16:35:08 -0700 (PDT) Received: by debian.me (Postfix, from userid 1000) id B9FC381A1A74; Fri, 1 Sep 2023 06:35:04 +0700 (WIB) Date: Fri, 1 Sep 2023 06:35:04 +0700 From: Bagas Sanjaya To: Mikhail Gavrilov , Hugh Dickins , Andrew Morton Cc: Linux List Kernel Mailing , Linux Memory Management List , Linux Regressions Subject: Re: 6.6/regression/bisected - after commit a349d72fd9efc87c8fd1d16d3164752d84a7275b system stopped booting Message-ID: References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="YlrlQSBP360Gwvyd" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --YlrlQSBP360Gwvyd Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 01, 2023 at 03:45:28AM +0500, Mikhail Gavrilov wrote: > Hi, > next release cycle, and another regression. > Yesterday after another kernel update in Fedora Rawhide system stopped bo= oting. > Today thanks to git bisect, I found out that this is a commit: >=20 > =E2=9D=AF git bisect bad > a349d72fd9efc87c8fd1d16d3164752d84a7275b is the first bad commit > commit a349d72fd9efc87c8fd1d16d3164752d84a7275b > Author: Hugh Dickins > Date: Tue Jul 11 21:30:40 2023 -0700 >=20 > mm/pgtable: add rcu_read_lock() and rcu_read_unlock()s >=20 > Patch series "mm: free retracted page table by RCU", v3. >=20 > Some mmap_lock avoidance i.e. latency reduction. Initially just for= the > case of collapsing shmem or file pages to THPs: the usefulness of > MADV_COLLAPSE on shmem is being limited by that mmap_write_lock it > currently requires. >=20 > Likely to be relied upon later in other contexts e.g. freeing of emp= ty > page tables (but that's not work I'm doing). mmap_write_lock avoidan= ce > when collapsing to anon THPs? Perhaps, but again that's not work I've > done: a quick attempt was not as easy as the shmem/file case. >=20 > These changes (though of course not these exact patches) have been in > Google's data centre kernel for three years now: we do rely upon them. >=20 >=20 > This patch (of 13): >=20 > Before putting them to use (several commits later), add rcu_read_lock= () to > pte_offset_map(), and rcu_read_unlock() to pte_unmap(). Make this a > separate commit, since it risks exposing imbalances: prior commits ha= ve > fixed all the known imbalances, but we may find some have been missed. >=20 > Link: https://lkml.kernel.org/r/7cd843a9-aa80-14f-5eb2-33427363c20@go= ogle.com > Link: https://lkml.kernel.org/r/d3b01da5-2a6-833c-6681-67a3e024a16f@g= oogle.com > Signed-off-by: Hugh Dickins > ... > Signed-off-by: Andrew Morton >=20 > include/linux/pgtable.h | 4 ++-- > mm/pgtable-generic.c | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) >=20 > It looks like the hang happens so early that when booting into a > working kernel and running "journalctl -b -1" I see in the console the > log of the previous kernel which was booted before the problematic > kernel. > Therefore, I apologize that I can't provide the kernel logs. > I can provides only photos when backtrace appears on my monitor: > Here we waiting: https://ibb.co/5xmm0BH > And then I see backtrace: https://ibb.co/TLLGFNP >=20 > Unfortunately I can't revert commit > a349d72fd9efc87c8fd1d16d3164752d84a7275b for testing more fresh builds > because of conflicts. >=20 > My hardware: https://linux-hardware.org/?probe=3Ddd5735f315 > I also attached kernel build config and full bisect log. >=20 Thanks for the regression report. I'm adding it to regzbot: #regzbot ^introduced: a349d72fd9efc8 #regzbot title: rcu_read_{lock,unlock}() causes unbootable system with back= trace --=20 An old man doll... just what I always wanted! - Clara --YlrlQSBP360Gwvyd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQSSYQ6Cy7oyFNCHrUH2uYlJVVFOowUCZPEjogAKCRD2uYlJVVFO o3dwAP9Mvs2XVvCKGsLeMpZkFeVo271NAUlejx1tpCkRufzuqAD/cHTFPuH2Lrz+ VZSQQkes8U+rX0p0LUA/E/DCx4UsiAo= =pMfl -----END PGP SIGNATURE----- --YlrlQSBP360Gwvyd--