From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) (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 B37BE1429F for ; Thu, 31 Aug 2023 23:35:09 +0000 (UTC) Received: by mail-pl1-f180.google.com with SMTP id d9443c01a7336-1bf11b1c7d0so17482185ad.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=lists.linux.dev; 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=FoL3QiNFyipaFmynYBKUqCGyIN8iEGOJJsNpS5a01Xh/atNTYrlCR0BZM1omCoSrsC YPiV7It5zDUAiGJl+YH46dAVTm2XPqy4SUnC9pR8jjotxoCdUPjnIhWWZyMDR3yC1mqH N+mkfqqsrkdTvaagvN0YQpEIKZuXHjqP3sVE9GivQ8ftofdVLd16HpfDTBEl/RpcD2Az YDdG4Z5KCYlNhUBqP4rHLWaG30pG7xoSiWlMcjf2d79tJQMiBxAhLirKJq6bxOiFfyOb Iy0L957857UV55godmuNWzkYPHm+xXGzz/sd9mpz72uaINUp/iz8TcHclZwKZqpt2f1t nmRQ== 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=XwWmnHHLDjyaJ5wN3Zh9Tyb0EAxKDIl+IV/Cu4ZoRhx2AXcMsTuIgidIuctOqq9fry OGnipNZpoG8xpqo07lHfbf4AzL0H7dejNNm9M1HGITJKrg75Q2OeVyuhybxxkFE4IK79 p86lpkoDTcdO5bmafRctcVwgp5t4C0o//doKgHepbe1BXSVF9QIHcomcBuQTrUnn2BCQ JpSpbKqF2IgN/1CoIc+8m6ZfYC+a8hj7qxMyOD1S0Z6X3wwt237Ja+s6AukWHSfWkdxb OBeXETVbynveZAZdaHTor5NRe6b/xHk+4VD+KNgK5pJ9TEgxaTF0ZyppTEVYRe0xTtt5 7/cQ== X-Gm-Message-State: AOJu0Yx6FJ4Z6U2cr8vvT89olpSXtfK0KtHN7v7IMRLZiG8F+kHCB33i HarMXLz87YKRaqfRClPbfcI= 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: Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="YlrlQSBP360Gwvyd" Content-Disposition: inline In-Reply-To: --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--