Red Hat Bugzilla – Bug 441454
cpufreq stress test cause ondemand governor deadlock
Last modified: 2015-05-08 09:57:48 EDT
Description of problem:
cpufreq stress test will cause ondemand governor deadlock on Harwich-
Truland,4x Xeon 7130 3.2GHz;E8501;DP 2x1M L2 8M L3 800MHz, RHEL5.2 snapshot1.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. get the cpufreq_stress test case in the attachment
2 [details]. cd cpufreq_stress/initial; make
After 7~8 hours, ps -aux find that kondemand daemon deadlock.
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor will hung.
Created attachment 301612 [details]
cpufreq_stress test case and and sysrq+t log and ps -aux log.
This is actually a kernel problem, not a cpuspeed package problem, reassigning
to the correct component.
John please work with Matthew and determine if this is still a problem after the
RHEL 5.3 updates to power management are in the kernel. Please work on
reproducing the problem in the Westford lab.
At a guess, it's CPU hotplug related - the locking for that was broken for a
long time. I'll look into the current code and see if there's an obvious fix.
Is this related to Bug 449004
(In reply to comment #5)
> Is this related to Bug 449004
I don't think so. AFAICT, someone did a alt-sysrq-t (and that caused the soft
lockup warnings at the end of the sysrq dump). It looks significantly different
from the 449004 (where we see a series of softlockup messages).
Let us know if they are related. I wasn't sure if you created this Bugzilla,
then created the Issue Tracker, which then spawned Bug 449004
Yes. this bug is relate to Bug 449004. Bug 449004 has the modified test case
with which we can easier to reproduce the bug. so this bug is duplicate with
*** This bug has been marked as a duplicate of bug 449004 ***