From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: CPU Utilization Date: Mon, 12 Dec 2005 17:01:24 -0600 Message-ID: <439E0144.6020107@us.ibm.com> References: <5440A5A36B8CED4B9F54524343CB6B68FD133F@xmb-rtp-215.amer.cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5440A5A36B8CED4B9F54524343CB6B68FD133F@xmb-rtp-215.amer.cisco.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Dave Thompson (davetho)" Cc: xen-devel@lists.xensource.com, Rob Gardner List-Id: xen-devel@lists.xenproject.org top isn't smart enough to realize that for a portion of the running time, a domain has been pre-empted out and is not running. top will then charge whatever was running at pre-emption time for the time that other domain running. Regards, Anthony Liguori Dave Thompson (davetho) wrote: > > > > >>-----Original Message----- >>From: Rob Gardner [mailto:rob.gardner@hp.com] >>Sent: Monday, December 12, 2005 1:23 PM >>To: Dave Thompson (davetho) >>Cc: xen-devel@lists.xensource.com >>Subject: Re: [Xen-devel] CPU Utilization >> >>Dave Thompson (davetho) wrote: >> >> >> >>>I have a question concerning the CPU utilization number provided by >>>the 'xm top' command in xen 3.0. I've noticed that if I run a TCP >>>performance tool on domain 0 which simply receives and echos back >>>a TCP stream, the output of 'xm top' during the test does not match >>>up with the output of 'top' on domain 0 in terms of CPU utilization >>>(nor with the CPU utilization computed by the test program). >>> >>>... >>> >>>Any idea why these displays disagree? >>> >>> >>> >>> >>Top shows cpu usage for user processes in dom0, while xm top >>shows cpu usage for the domain, which includes cpu time spent >>in the dom0 kernel. >> >> > >Doesn't top's CPU summary line show both? I thought us=user space, >sy=system, ni=nice, id=idle, hi=hwintr, si=softintr. So in my >example 1% in user space, 7.3% in system level, 3.3% in h/w intr, >and 15% in soft intr. Total of 26.6% utilized of which 25.6% is >in kernel. > > > >>Perhaps the thing you're running incurs lots of kernel cpu >>time, but not >>user time? >> >>Rob >> >> >> > >_______________________________________________ >Xen-devel mailing list >Xen-devel@lists.xensource.com >http://lists.xensource.com/xen-devel > > >