Linux 2.6 cpu wait/idle time change with 1.6.3

[jroberson]

I just upgraded to 1.6.3 from 1.6.2 and noticed a graph is significantly different. It is a stacked graph that uses the system.cpu.util key with idle,nice,system,user types. Previously, I had a stacked graph with these values, sans "wait" as that isn't supported in Linux 2.6. Before 1.6.3 all values added up to 100% (or close to it). After 1.6.3 there is a significant chunk missing, i.e. not all values add up to 100%. I checked the system and watched 'top' for a bit and noticed quite a bit of "wait" %cpu.

Here's the beef: I don't know whether 1.6.3 causes more wait%cpu or if the system.cpu.util key is merely recording cpu usage values differently. :confused: Anybody have any comment or notice the same things?

[Alexei]

This is because we also support iowait,interrupt,softirq and steal in 1.6.3. Sum of all eight percentages is 100%. In pre 1.6.3 releases sum of four (idle,nice,system,user) percentages was 100%.

[xaeth]

I just installed from the 1.6.5 fedora RPM and we are getting unsupported for wait. I noticed that in the code it seems to look for 'iowait' not 'wait' (which is whats in the Template_Linux). I tried making this change and still got unsupported.

I know they used to provide a patch to support these features, but I just dug through the source RPM and they are not touching the wait part anymore, and I do see the code for it.


Maybe something else is wrong? Anyone else having an issue with this?

[xaeth]

Despite a handful of refreshes and waiting before I posted, I went to another host and it was working, went back to the original host I tested, and it was working there.

So changing the template to reference 'iowait' not 'wait' worked for me. So i guess the template just needs to be updated?