Re: High load average on idle machine running 2.6.32

[James Pearson <james-p@moving-picture.com>]

James Pearson wrote:
> I've booted a 64 bit 2.6.32 kernel on dual processor, quad core Xeon 
> E5440 machine. The load average when the machine is idle varies between 
> 2 and 3.
> 
> When using a 2.6.31 kernel on the same machine, the load average when 
> idle is nearly 0
> 
> The kernel doesn't use modules - all that is needed is compiled in. The 
> machine uses NFS-root
> 
> Strangely, when I run 'iftop' (from http://www.ex-parrot.com/pdw/iftop/) 
> using the 2.6.32 kernel, the load average drops to below 0.5  - stop 
> running iftop, and the load average climbs again ...
> 
> Any idea what might be causing this?

It looks like whatever is causing this happened between 2.6.31-git7 and 
2.6.31-git8 - unfortunately I don't know how to find out what change 
caused this ...

Also, if I 'hot-unplug' CPUs 1 to 7, the load average drops to 0 - when 
I re-enable theses CPUs, the load average climbs.

I guess this is a problem with my particular config - or maybe because 
I'm using NFS-root (the root file system is readonly), or using a 
non-module kernel?

Thanks

James Pearson