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From:   Oleksandr Natalenko <oleksandr@natalenko.name>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     linux-stable@vger.kernel.org,
        Chris Clayton <chris2553@googlemail.com>,
        Chris Rankin <rankincj@gmail.com>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Josh Triplett <josh@joshtriplett.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Joel Fernandes <joel@joelfernandes.org>, rcu@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org
Subject: Re: linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359
Date:   Sun, 18 Jul 2021 23:01:24 +0200
Message-ID: <2245518.LNIG0phfVR@natalenko.name>
In-Reply-To: <c9fd1311-662c-f993-c8ef-54af036f2f78@googlemail.com>
References: <c9fd1311-662c-f993-c8ef-54af036f2f78@googlemail.com>
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Precedence: bulk

Hello.

On sobota 17. =C4=8Dervence 2021 22:22:08 CEST Chris Clayton wrote:
> I checked the output from dmesg yesterday and found the following warning:
>=20
> [Fri Jul 16 09:15:29 2021] ------------[ cut here ]------------
> [Fri Jul 16 09:15:29 2021] WARNING: CPU: 11 PID: 2701 at
> kernel/rcu/tree_plugin.h:359 rcu_note_context_switch+0x37/0x3d0 [Fri Jul =
16
> 09:15:29 2021] Modules linked in: uas hidp rfcomm bnep xt_MASQUERADE
> iptable_nat nf_nat xt_LOG nf_log_syslog xt_limit xt_multiport xt_conntrack
> iptable_filter btusb btintel wmi_bmof uvcvideo videobuf2_vmalloc
> videobuf2_memops videobuf2_v4l2 videobuf2_common coretemp hwmon
> snd_hda_codec_hdmi x86_pkg_temp_thermal snd_hda_codec_realtek
> snd_hda_codec_generic ledtrig_audio snd_hda_intel snd_intel_dspcfg
> snd_hda_codec snd_hwdep snd_hda_core i2c_i801 i2c_smbus iwlmvm mac80211
> iwlwifi i915 mei_me mei cfg80211 intel_lpss_pci intel_lpss wmi
> nf_conntrack_ftp xt_helper nf_conntrack nf_defrag_ipv4 tun
> [Fri Jul 16 09:15:29 2021] CPU: 11 PID: 2701 Comm: lpqd Not tainted 5.13.2
> #1 [Fri Jul 16 09:15:29 2021] Hardware name: Notebook                    =
 =20
>   NP50DE_DB                       /NP50DE_DB , BIOS 1.07.04 02/17/2020
> [Fri Jul 16 09:15:29 2021] RIP: 0010:rcu_note_context_switch+0x37/0x3d0
> [Fri Jul 16 09:15:29 2021] Code: 02 00 e8 ec a0 6c 00 89 c0 65 4c 8b 2c 25
> 00 6d 01 00 48 03 1c c5 80 56 e1 b6 40 84 ed 75 0d 41 8b 95 04 03 00 00 85
> d2 7e 02 <0f> 0b 65 48 8b 04 25 00 6d 01 00 8b 80 04 03 00 00 85 c0 7e 0a
> 41 [Fri Jul 16 09:15:29 2021] RSP: 0000:ffffb5d483837c70 EFLAGS: 00010002
> [Fri Jul 16 09:15:29 2021] RAX: 000000000000000b RBX: ffff9b77806e1d80 RC=
X:
> 0000000000000100 [Fri Jul 16 09:15:29 2021] RDX: 0000000000000001 RSI:
> ffffffffb6d82ead RDI: ffffffffb6da5e4e [Fri Jul 16 09:15:29 2021] RBP:
> 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [Fri Jul 16
> 09:15:29 2021] R10: 000000067bce4fff R11: 0000000000000000 R12:
> ffff9b77806e1100 [Fri Jul 16 09:15:29 2021] R13: ffff9b734a833a00 R14:
> ffff9b734a833a00 R15: 0000000000000000 [Fri Jul 16 09:15:29 2021] FS:=20
> 00007fccbfc5fe40(0000) GS:ffff9b77806c0000(0000) knlGS:0000000000000000
> [Fri Jul 16 09:15:29 2021] CS:  0010 DS: 0000 ES: 0000 CR0:
> 0000000080050033 [Fri Jul 16 09:15:29 2021] CR2: 00007fccc2db7290 CR3:
> 00000003fb0b8002 CR4: 00000000007706e0 [Fri Jul 16 09:15:29 2021] PKRU:
> 55555554
> [Fri Jul 16 09:15:29 2021] Call Trace:
> [Fri Jul 16 09:15:29 2021]  __schedule+0x86/0x810
> [Fri Jul 16 09:15:29 2021]  schedule+0x40/0xe0
> [Fri Jul 16 09:15:29 2021]  io_schedule+0x3d/0x60
> [Fri Jul 16 09:15:29 2021]  wait_on_page_bit_common+0x129/0x390
> [Fri Jul 16 09:15:29 2021]  ? __filemap_set_wb_err+0x10/0x10
> [Fri Jul 16 09:15:29 2021]  __lock_page_or_retry+0x13f/0x1d0
> [Fri Jul 16 09:15:29 2021]  do_swap_page+0x335/0x5b0
> [Fri Jul 16 09:15:29 2021]  __handle_mm_fault+0x444/0xb20
> [Fri Jul 16 09:15:29 2021]  handle_mm_fault+0x5c/0x170
> [Fri Jul 16 09:15:29 2021]  ? find_vma+0x5b/0x70
> [Fri Jul 16 09:15:29 2021]  exc_page_fault+0x1ab/0x610
> [Fri Jul 16 09:15:29 2021]  ? fpregs_assert_state_consistent+0x19/0x40
> [Fri Jul 16 09:15:29 2021]  ? asm_exc_page_fault+0x8/0x30
> [Fri Jul 16 09:15:29 2021]  asm_exc_page_fault+0x1e/0x30
> [Fri Jul 16 09:15:29 2021] RIP: 0033:0x7fccc2d3c520
> [Fri Jul 16 09:15:29 2021] Code: 68 4c 00 00 00 e9 20 fb ff ff ff 25 7a ad
> 07 00 68 4d 00 00 00 e9 10 fb ff ff ff 25 72 ad 07 00 68 4e 00 00 00 e9 00
> fb ff ff <ff> 25 6a ad 07 00 68 4f 00 00 00 e9 f0 fa ff ff ff 25 62 ad 07
> 00 [Fri Jul 16 09:15:29 2021] RSP: 002b:00007ffebd529048 EFLAGS: 00010293
> [Fri Jul 16 09:15:29 2021] RAX: 0000000000000001 RBX: 00007fccc46e2890 RC=
X:
> 0000000000000010 [Fri Jul 16 09:15:29 2021] RDX: 0000000000000010 RSI:
> 0000000000000000 RDI: 00007fccc46e2890 [Fri Jul 16 09:15:29 2021] RBP:
> 000056264f1dd4a0 R08: 000056264f21aba0 R09: 000056264f1f58a0 [Fri Jul 16
> 09:15:29 2021] R10: 0000000000000007 R11: 0000000000000246 R12:
> 000056264f21ac00 [Fri Jul 16 09:15:29 2021] R13: 000056264f1e0a30 R14:
> 00007ffebd529080 R15: 00000000000dd87b [Fri Jul 16 09:15:29 2021] ---[ end
> trace c8b06e067d8b0fc2 ]---
>=20
> At the time the warning was issued I was creating a (weekly) backup of my
> linux system (home-brewed based on the guidance from Linux From Scratch).
> My backup routine is completed by copying the archive files (created with
> dar) and a directory that contains about 7000 source and binary rpm files
> to an external USB drive. I didn't spot the warning until later in the da=
y,
> so I'm not sure exactly where I was in my backup process.
>=20
> I haven't seen this warning before. Consequently, I don;t know how easy (=
or
> otherwise) it is to reproduce.
>=20
> Let me know if I can provide any additional diagnostics, but please cc me=
 as
> I'm not subscribed.

Confirming the same for me with v5.13.2, and cross-referencing another
report [1] against v5.12.17.

Also Cc'ing relevant people on this.

Thanks.

[1] https://lore.kernel.org/lkml/CAK2bqVK0Q9YcpakE7_Rc6nr-E4e2GnMOgi5jJj=3D=
_Eh_1kEHLHA@mail.gmail.com/


=2D-=20
Oleksandr Natalenko (post-factum)