Re: [Xen-users] understanding xm top

["Ulrich Windl" <ulrich.windl@xxxxxxxxxxxxxxxxxxxx>]

On 20 Nov 2006 at 13:10, Julian Davison wrote:

> Ulrich Windl wrote:
> > On 15 Nov 2006 at 14:53, Tommie McAfee wrote:
> > 
> >>>  If xm top shows 10% CPU utilization for domain0, it means the CPU
> >>> utilization in domain0 is 10% of FOUR physcial CPUs. Is this right?
> >>>
> >>
> >> I  don't think the values scale that way percentage wise, because with 4
> >> physical cpu's, xm-top can show CPU(%) to be as high as 400%.  Unlike the
> > 
> > IMHO that's about as stupid as this output from procinfo:
> > 
> > idle  :   3d 16:05:53.82  99.8%
> > uptime:      22:03:12.95
> > 
> > How can the idle time be longer than the uptime? How can the CPU usage be 
> > more 
> > than 100%?
> 
> Because it's idle time for all the processors. In any given
> day, with a dual-processor machine, you get two days worth
> of CPU to use (1 day for each processor).
> It's curious that people are more interested in how much
> aggregated idle time their CPU(s) have, but only how long
> the entire box has been powered up.

It's still stupid, because when four CPUs are up, the uptime could also be 
multiplied by four. I still believe, CPU usage, cumulated or not cannot be 
higher 
than 100%, just as the idle time proportion cannot exceed 100%.

Ulrich


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users