From: Thomas Gleixner <tglx@linutronix.de>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: syzbot
<bot+e38be687a2450270a3b593bacb6b5795a7a74edb@syzkaller.appspotmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Kate Stewart <kstewart@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Philippe Ombredanne <pombredanne@nexb.com>,
syzkaller-bugs@googlegroups.com
Subject: Re: BUG: workqueue lockup (2)
Date: Sun, 3 Dec 2017 15:48:14 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1712031547010.2199@nanos> (raw)
In-Reply-To: <CACT4Y+bGNU1WkyHW3nNBg49rhg8uN1j0sA0DxRj5cmZOSmsWSQ@mail.gmail.com>
On Sun, 3 Dec 2017, Dmitry Vyukov wrote:
> On Sun, Dec 3, 2017 at 3:31 PM, syzbot
> <bot+e38be687a2450270a3b593bacb6b5795a7a74edb@syzkaller.appspotmail.com>
> wrote:
> > Hello,
> >
> > syzkaller hit the following crash on
> > 2db767d9889cef087149a5eaa35c1497671fa40f
> > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
> > compiler: gcc (GCC) 7.1.1 20170620
> > .config is attached
> > Raw console output is attached.
> >
> > Unfortunately, I don't have any reproducer for this bug yet.
> >
> >
> > BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 48s!
> > BUG: workqueue lockup - pool cpus=0-1 flags=0x4 nice=0 stuck for 47s!
> > Showing busy workqueues and worker pools:
> > workqueue events: flags=0x0
> > pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256
> > pending: perf_sched_delayed, vmstat_shepherd, jump_label_update_timeout,
> > cache_reap
> > workqueue events_power_efficient: flags=0x80
> > pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256
> > pending: neigh_periodic_work, neigh_periodic_work, do_cache_clean,
> > reg_check_chans_work
> > workqueue mm_percpu_wq: flags=0x8
> > pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
> > pending: vmstat_update
> > workqueue writeback: flags=0x4e
> > pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256
> > in-flight: 3401:wb_workfn
> > workqueue kblockd: flags=0x18
> > pwq 1: cpus=0 node=0 flags=0x0 nice=-20 active=1/256
> > pending: blk_mq_timeout_work
> > pool 4: cpus=0-1 flags=0x4 nice=0 hung=0s workers=11 idle: 3423 4249 92 21
>
>
> This error report does not look actionable. Perhaps if code that
> detect it would dump cpu/task stacks, it would be actionable.
That might be related to the RCU stall issue we are chasing, where a timer
does not fire for yet unknown reasons. We have a reproducer now and
hopefully a solution in the next days.
Thanks,
tglx
next prev parent reply other threads:[~2017-12-03 14:48 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <94eb2c03c9bc75aff2055f70734c@google.com>
2017-12-03 14:36 ` BUG: workqueue lockup (2) Dmitry Vyukov
2017-12-03 14:48 ` Thomas Gleixner [this message]
2017-12-04 11:08 ` Tetsuo Handa
2017-12-19 12:25 ` syzbot
2017-12-19 14:27 ` Tetsuo Handa
2017-12-19 14:40 ` Dmitry Vyukov
2017-12-19 16:37 ` Dmitry Vyukov
2017-12-20 10:55 ` Tetsuo Handa
2017-12-21 10:19 ` Dmitry Vyukov
2017-12-21 10:22 ` Dmitry Vyukov
2017-12-21 11:04 ` Dmitry Vyukov
2017-12-21 13:07 ` Tetsuo Handa
2017-12-28 13:43 ` Dmitry Vyukov
2018-05-12 21:52 ` Eric Biggers
2018-05-13 2:06 ` Tetsuo Handa
2018-05-13 3:32 ` Eric Biggers
2018-05-13 14:29 ` Tetsuo Handa
2018-05-13 14:35 ` Dmitry Vyukov
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