cpuspeed display no graph

[Jörg Frings-Fürst]

On saucy cpuspeed dont display any graph.

Running via munin-run:

> munin-run cpuspeed
cpu0.value 22000
cpu1.value 33000
cpu2.value 33000
cpu3.value 33000
cpu4.value 33000
cpu5.value 33000
cpu6.value 33000
cpu7.value 33000

No errors in any log-files in /var/log/munin

In /var/lib/munin/*/ are all 8 rrd-files.

In the dumps are all values NaN

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: munin-plugins-core 2.0.17-2ubuntu1.1
ProcVersionSignature: Ubuntu 3.11.0-18.32-generic 3.11.10.4
Uname: Linux 3.11.0-18-generic x86_64
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
Date: Sat Mar 22 11:30:08 2014
MarkForUpload: True
PackageArchitecture: all
SourcePackage: munin
UpgradeStatus: Upgraded to saucy on 2014-03-20 (1 days ago)

[Nick Lock (nick-lock)]

This is related to the bug in kernel 3.11 described here:

https://lkml.org/lkml/2013/9/7/126

As the contents of /sys/devices/system/cpu/cpu1/cpufreq/stats/time_in_state are incorrect (and never update), firstly there is a strong chance that the plugin will return values below $MINHZ - resulting in NaN being recorded.

Setting $MINHZ to 0 manually in the plugin code then returns 0 values on the graph, as the type is set as DERIVE... as the values returned from time_in_state never change, the derive is always zero. ;)

A kernel upgrade will probably fix the problem - the above page says that the patch was submitted for 3.12-rc1. You could either wait until 3.12 is released for Saucy, or upgrade to Tahr which has 3.13(?)

[Jörg Frings-Fürst (jff-de)]

Hi Nick,

I have already upgrade to trusty and it runs.

So I can close this bug.

Thanks for your work

Jörg