From: Anders Roxell <anders.roxell@linaro.org>
To: Marco Elver <elver@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>, Jann Horn <jannh@google.com>,
Mark Rutland <mark.rutland@arm.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
kasan-dev <kasan-dev@googlegroups.com>
Subject: Re: [PATCH] kfence: Avoid stalling work queue task without allocations
Date: Wed, 11 Nov 2020 16:01:33 +0100 [thread overview]
Message-ID: <CADYN=9LtdW3Bs29VSq2ygnNcb3ub_UBLj8tZg5ff5Zvojr5FWg@mail.gmail.com> (raw)
In-Reply-To: <CANpmjNM8MZphvkTSo=KgCBXQ6fNY4qo6NZD5SBHjNse_L9i5FQ@mail.gmail.com>
On Wed, 11 Nov 2020 at 09:29, Marco Elver <elver@google.com> wrote:
>
> On Wed, 11 Nov 2020 at 00:23, Anders Roxell <anders.roxell@linaro.org> wrote:
> [...]
> >
> > I gave them a spin on next-20201105 [1] and on next-20201110 [2].
> >
> > I eventually got to a prompt on next-20201105.
> > However, I got to this kernel panic on the next-20201110:
> >
> > [...]
> > [ 1514.089966][ T1] Testing event system initcall: OK
> > [ 1514.806232][ T1] Running tests on all trace events:
> > [ 1514.857835][ T1] Testing all events:
> > [ 1525.503262][ C0] hrtimer: interrupt took 10902600 ns
> > [ 1623.861452][ C0] BUG: workqueue lockup - pool cpus=0 node=0
> > flags=0x0 nice=0 stuck for 65s!
> > [...]
> > [ 7823.104349][ T28] Tainted: G W
> > 5.10.0-rc3-next-20201110-00008-g8dc06700529d #3
> > [ 7833.206491][ T28] "echo 0 >
> > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [ 7840.750700][ T28] task:kworker/0:1 state:D stack:26640 pid:
> > 1872 ppid: 2 flags:0x00000428
> > [ 7875.642531][ T28] Workqueue: events toggle_allocation_gate
> > [ 7889.178334][ T28] Call trace:
> > [ 7897.066649][ T28] __switch_to+0x1cc/0x1e0
> > [ 7905.326856][ T28] 0xffff00000f7077b0
> > [ 7928.354644][ T28] INFO: lockdep is turned off.
> > [ 7934.022572][ T28] Kernel panic - not syncing: hung_task: blocked tasks
> > [ 7934.032039][ T28] CPU: 0 PID: 28 Comm: khungtaskd Tainted: G
> > W 5.10.0-rc3-next-20201110-00008-g8dc06700529d #3
> > [ 7934.045586][ T28] Hardware name: linux,dummy-virt (DT)
> > [ 7934.053677][ T28] Call trace:
> > [ 7934.060276][ T28] dump_backtrace+0x0/0x420
> > [ 7934.067635][ T28] show_stack+0x38/0xa0
> > [ 7934.091277][ T28] dump_stack+0x1d4/0x278
> > [ 7934.098878][ T28] panic+0x304/0x5d8
> > [ 7934.114923][ T28] check_hung_uninterruptible_tasks+0x5e4/0x640
> > [ 7934.123823][ T28] watchdog+0x138/0x160
> > [ 7934.131561][ T28] kthread+0x23c/0x260
> > [ 7934.138590][ T28] ret_from_fork+0x10/0x18
> > [ 7934.146631][ T28] Kernel Offset: disabled
> > [ 7934.153749][ T28] CPU features: 0x0240002,20002004
> > [ 7934.161476][ T28] Memory Limit: none
> > [ 7934.171272][ T28] ---[ end Kernel panic - not syncing: hung_task:
> > blocked tasks ]---
> >
> > Cheers,
> > Anders
> > [1] https://people.linaro.org/~anders.roxell/output-next-20201105-test.log
> > [2] https://people.linaro.org/~anders.roxell/output-next-20201110-test.log
>
> Thanks for testing. The fact that it passes on next-20201105 but not
> on 20201110 is strange. If you boot with KFENCE disabled (boot param
> kfence.sample_interval=0), does it boot?
This is my qemu cmdline with kfence.sample_interval=0
$ qemu-system-aarch64 --enable-kvm -cpu cortex-a53 -kernel
Image-20201110-test -serial stdio -monitor none -nographic -m 2G -M
virt -fsdev local,id=root,path=/srv/kvm/tmp/stretch/arm64-test,security_model=none,writeout=immediate
-device virtio-rng-pci -device
virtio-9p-pci,fsdev=root,mount_tag=/dev/root -append "root=/dev/root
rootfstype=9p rootflags=trans=virtio console=ttyAMA0,38400n8
earlycon=pl011,0x9000000 initcall_debug softlockup_panic=0
security=none kpti=no kfence.sample_interval=0"
This is the result, I managed to get to the prompt. see
https://people.linaro.org/~anders.roxell/output-next-20201110-test-2.log
Cheers,
Anders
>
> In your log [2] I see a number of "BUG: workqueue lockup ..." but that
> doesn't make sense, at least I don't think the KFENCE work item is
> causing this. It'd be interesting to bisect what changed between
> 20201105 and 20201110, but I have a suspicion that might take too
> long. Short of that, let me see if there are any changes between the 2
> that look like it might be causing this.
>
> Thanks,
> -- Marco
next prev parent reply other threads:[~2020-11-11 15:01 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 13:53 [PATCH] kfence: Avoid stalling work queue task without allocations Marco Elver
2020-11-10 14:25 ` Dmitry Vyukov
2020-11-10 14:53 ` Marco Elver
2020-11-10 23:23 ` Anders Roxell
2020-11-11 8:29 ` Marco Elver
2020-11-11 13:38 ` Marco Elver
2020-11-11 18:05 ` Steven Rostedt
2020-11-11 18:23 ` Paul E. McKenney
2020-11-11 18:34 ` Marco Elver
2020-11-11 19:21 ` Paul E. McKenney
2020-11-11 20:21 ` Marco Elver
2020-11-12 0:11 ` Paul E. McKenney
2020-11-12 12:49 ` Marco Elver
2020-11-12 16:14 ` Marco Elver
2020-11-12 17:54 ` Paul E. McKenney
2020-11-12 18:12 ` Marco Elver
2020-11-12 20:00 ` Paul E. McKenney
2020-11-13 11:06 ` Marco Elver
2020-11-13 17:20 ` Paul E. McKenney
2020-11-13 17:57 ` Paul E. McKenney
2020-11-17 10:52 ` Marco Elver
2020-11-17 18:29 ` Paul E. McKenney
2020-11-18 22:56 ` Marco Elver
2020-11-18 23:38 ` Paul E. McKenney
2020-11-19 12:53 ` Marco Elver
2020-11-19 15:14 ` Paul E. McKenney
2020-11-19 17:02 ` Marco Elver
2020-11-19 18:48 ` Paul E. McKenney
2020-11-19 19:38 ` linux-next: stall warnings and deadlock on Arm64 (was: [PATCH] kfence: Avoid stalling...) Marco Elver
2020-11-19 21:35 ` Paul E. McKenney
2020-11-19 22:53 ` Will Deacon
2020-11-20 10:30 ` Mark Rutland
2020-11-20 14:03 ` Marco Elver
2020-11-23 19:32 ` Mark Rutland
2020-11-24 14:03 ` Marco Elver
2020-11-24 15:01 ` Paul E. McKenney
2020-11-24 19:43 ` Mark Rutland
2020-11-24 20:32 ` Steven Rostedt
2020-11-24 19:30 ` Mark Rutland
2020-11-25 9:45 ` Marco Elver
2020-11-25 10:28 ` Mark Rutland
2020-11-20 14:19 ` Marco Elver
2020-11-20 14:39 ` Paul E. McKenney
2020-11-20 15:22 ` Mark Rutland
2020-11-20 17:38 ` Paul E. McKenney
2020-11-20 18:02 ` Mark Rutland
2020-11-20 18:57 ` Paul E. McKenney
2020-11-20 15:26 ` Steven Rostedt
2020-11-20 18:17 ` Marco Elver
2020-11-20 18:57 ` Steven Rostedt
2020-11-20 19:16 ` Steven Rostedt
2020-11-20 19:22 ` Marco Elver
2020-11-20 19:27 ` [PATCH] kfence: Avoid stalling work queue task without allocations Steven Rostedt
2020-11-23 15:27 ` Marco Elver
2020-11-23 16:28 ` Steven Rostedt
2020-11-23 16:36 ` Steven Rostedt
2020-11-23 18:53 ` Marco Elver
2020-11-23 18:42 ` Steven Rostedt
2020-11-24 2:59 ` Boqun Feng
2020-11-24 3:44 ` Paul E. McKenney
2020-11-11 18:21 ` Paul E. McKenney
2020-11-11 15:01 ` Anders Roxell [this message]
2020-11-11 15:22 ` Marco Elver
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