public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: John Ogness <john.ogness@linutronix.de>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Petr Mladek <pmladek@suse.com>
Cc: kernel test robot <oliver.sang@intel.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	lkp@lists.01.org, lkp@intel.com, zhengjun.xing@linux.intel.com
Subject: Re: [printk]  b031a684bf: INFO:rcu_tasks_detected_stalls_on_tasks
Date: Wed, 27 Jan 2021 22:28:59 +0106	[thread overview]
Message-ID: <87bldaaxcc.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <YA+gAV1kW8Ru1+Bo@jagdpanzerIV.localdomain>

On 2021-01-26, Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
> AFAIU this is just 'modprobe rcutorture'

I was finally able to trigger this by using my workstation:

    Intel(R) Core(TM) i5-8259U CPU @ 2.30GHz
    Debian/buster
    QEMU 3.1.0 (Debian 1:3.1+dfsg-8+deb10u8)

instead of my build server:

    Intel(R) Xeon(R) CPU E5-2697 v4 @ 2.30GHz
    Debian/bullseye
    QEMU 5.2.0 (Debian 1:5.2+dfsg-3)

I don't know what factors contributed, but I wanted to share my success
in reproducing the reported problem. Instead of using lkp, I am manually
booting with:

$ kvm -cpu host -smp 2 -m 8G -nographic \
      -kernel bzImage -append "console=ttyS0,115200 loglevel=6" \
      -initrd initrd

My initrd is a minimal busybox rootfs that runs:

# modprobe rcutorture onoff_interval=3 onoff_holdoff=30 torture_type=tasks

(Those are the same modprobe parameters used by the lkp job.)

After about a minute I see:

[   47.268292] tasks-torture: rcu_torture_read_exit: Start of episode
[   51.273365] tasks-torture: rcu_torture_read_exit: End of episode
[   55.823306] smpboot: do_boot_cpu failed(-1) to wakeup CPU#0
[   55.824350] tasks-torture:torture_onoff task: online 0 failed: errno -5
[   55.830661] tasks-torture:torture_onoff task: online 0 failed: errno -5
[   55.848524] tasks-torture:torture_onoff task: online 0 failed: errno -5

I will start to debug this now.

John Ogness

  reply	other threads:[~2021-01-27 21:25 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-22  8:13 [printk] b031a684bf: INFO:rcu_tasks_detected_stalls_on_tasks kernel test robot
2021-01-22 16:21 ` Petr Mladek
2021-01-26  4:52   ` Sergey Senozhatsky
2021-01-27 21:22     ` John Ogness [this message]
2021-01-27 23:29       ` John Ogness
2021-01-28  8:30       ` Sergey Senozhatsky
2021-01-28 11:26         ` John Ogness
2021-01-28 14:51           ` Petr Mladek
2021-01-28 15:42             ` John Ogness
2021-01-28 16:36               ` Petr Mladek
2021-01-28 17:36                 ` John Ogness
2021-01-28 21:38                   ` John Ogness
2021-01-23  2:44 ` Sergey Senozhatsky
2021-02-02 17:13 ` John Ogness
2021-02-04 21:32   ` John Ogness
2021-02-05  9:32     ` Petr Mladek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87bldaaxcc.fsf@jogness.linutronix.de \
    --to=john.ogness@linutronix.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lkp@intel.com \
    --cc=lkp@lists.01.org \
    --cc=oliver.sang@intel.com \
    --cc=pmladek@suse.com \
    --cc=sergey.senozhatsky@gmail.com \
    --cc=zhengjun.xing@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox