WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] understanding xm top

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] understanding xm top
From: "Ulrich Windl" <ulrich.windl@xxxxxxxxxxxxxxxxxxxx>
Date: Mon, 20 Nov 2006 10:13:35 +0100
Delivery-date: Mon, 20 Nov 2006 01:14:33 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <4560F281.6060509@xxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Organization: Universitaet Regensburg, Klinikum
Priority: normal
References: <455C308D.14980.FCB5CD4@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
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