Re: Stolen and degraded time and schedulers

[Jeremy Fitzhardinge <jeremy@goop.org>]

Rik van Riel wrote:
> Jeremy Fitzhardinge wrote:
>
>> It doesn't matter why you didn't get the time; 
>
> Oh, but it does.

I meant specifically from a scheduling perspective.

> System administrators can use steal time the same way they
> use iowait time: to spot bottlenecks on their systems.
>
> If you have a lot of iowait time, you know you want either
> faster IO or more memory.
>
> If you have a lot of steal time, you know you need to spread
> your virtual machines over more CPUs.
>
> Steal time allows you to see the difference between a busy
> system and an overloaded system.

Sure, the various accounting tools can go into as much detail as you
want.  I just added stolen time accounting to the xen-pv_ops patchset
which is equivalent to the xen-unstable stolen time accounting.  Is that
sufficient for these purposes?

    J