watchdog/0 100% cpu usage

[Omid Kosari]

Description: Ubuntu 12.04 LTS
Release: 12.04
Linux Cache 3.2.0-24-generic #39-Ubuntu SMP Mon May 21 16:52:17 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

sometimes system not responding at all . it replies to pings but running a simple command takes more than 15 minutes to complete .

 i found somebody else has same problem in http://askubuntu.com/questions/134899/watchdog-0-process-using-all-my-cpu-suddenly .

i just tried to a dmesg and after many minutes attached lines displayed .

this time i tried to run "Process Filedescriptor Allocation" in squid3 cachemgr.cgi but other times the watchdog automatically got 100% of cpu

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

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[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[David Zschille (david-zschille)]

I have it since this week that watchdog/0 (seen in htop) eats my cpu. Working with my laptop is not really possible. Last week it was working fine.

[Fabounet (fabounet03)]

same here with 3.2.0-34-generic-pae dual core AMD, on Ubuntu 12.04,
both cores are at 100% for about a minute

[Juan Lanus (juan-lanus)]

I'm on 13.04 in a Thinkpad T61. As of ~Sep 27 (I updated) the cursor become jumpy, seems watchdog is to be blamed:

top - 10:50:36 up 14:05, 3 users, load average: 1.10, 1.41, 1.44
Tasks: 224 total, 2 running, 221 sleeping, 1 stopped, 0 zombie
%Cpu(s): 4.8 us, 18.5 sy, 0.3 ni, 75.1 id, 0.0 wa, 0.0 hi, 1.3 si, 0.0 st
KiB Mem: 2008832 total, 1887936 used, 120896 free, 152048 buffers
KiB Swap: 2053116 total, 45204 used, 2007912 free, 608248 cached

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
   12 root rt 0 0 0 0 S 59.2 0.0 59:27.37 watchdog/1 <=========
 3854 root 20 0 0 0 0 R 9.6 0.0 1:05.65 kworker/1:1
 2033 jlanus 20 0 1439m 68m 21m S 4.0 3.5 5:32.94 compiz
 1130 root 20 0 315m 37m 19m S 2.3 1.9 3:16.05 Xorg
 2051 jlanus 20 0 556m 12m 9312 S 1.3 0.7 3:00.65 indicator-multi
 2297 jlanus 20 0 609m 23m 12m S 1.3 1.2 3:10.58 unity-panel-ser
 2299 jlanus 20 0 545m 6484 3540 S 1.0 0.3 1:54.10 hud-service
 1082 mongodb 20 0 341m 32m 3144 S 0.7 1.7 1:03.78 mongod
 1278 root 35 15 22008 8216 968 S 0.7 0.4 0:20.58 preload

[Paul Gear (paulgear)]

On my dual 8-core HT Dell R720 (32 virtual cores), watchdogs consume lots of CPU, pushing load up over 80 regularly. Could be related to https://bugzilla.kernel.org/show_bug.cgi?id=42981

[Paul Gear (paulgear)]

Upgrading my system to kernel 3.8.0-31.46~precise1 (via the linux-image-generic-lts-raring package) solved the issue with poor performance for me.

[Paul Crawford (psc-sat)]

Note the "watchdog/0" thread you see is not the system monitoring daemon. Rather it has a similar task for kernel scheduling:

http://linux-tips.org/t/what-is-kernel-soft-lockup/78