kernel call traces from blk-core.c

[Jeff Waugh]

I'm getting some kernel call traces dumped in dmesg from blk-core.c, on my Xen-based Linode server (Ubuntu 10.04.1 LTS with linux-image-2.6.32-24-generic).

Someone appears to have seen similar traces running under qemu-kvm, and Christoph Hellwig responded with a potential fix.

   Report: http://kerneltrap.org/mailarchive/linux-kvm/2010/1/27/6257360 (Marti Raudsepp)
   Potential fix: http://kerneltrap.org/mailarchive/linux-kvm/2010/1/29/6257464 (Christoph Hellwig)

I'll attach dmesg and so on.

[Jeff Waugh (jdub)]

Would this perhaps be related? Every now and then my Linode disk subsystem seizes up, with messages similar to those below...

[26760.068047] INFO: task kjournald:187 blocked for more than 120 seconds.
[26760.068066] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.068278] INFO: task rsyslogd:2934 blocked for more than 120 seconds.
[26760.068289] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.068548] INFO: task flush-202:0:366 blocked for more than 120 seconds.
[26760.068559] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.068877] INFO: task nginx:718 blocked for more than 120 seconds.
[26760.068887] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.069035] INFO: task nginx:720 blocked for more than 120 seconds.
[26760.069044] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.069197] INFO: task nginx:721 blocked for more than 120 seconds.
[26760.069206] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.069455] INFO: task nginx:722 blocked for more than 120 seconds.
[26760.069465] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.069720] INFO: task collectd:833 blocked for more than 120 seconds.
[26760.069730] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.069844] INFO: task collectd:834 blocked for more than 120 seconds.
[26760.069853] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[26760.070010] INFO: task collectd:837 blocked for more than 120 seconds.
[26760.070019] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

[Jeff Waugh (jdub)]

This Debian bug report may be related, not sure:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=516374

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 618529

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.