From mboxrd@z Thu Jan 1 00:00:00 1970 From: xuehai zhang Subject: Re: MPI benchmark performance gap between native linux anddomU Date: Tue, 05 Apr 2005 17:39:32 -0500 Message-ID: <425313A4.90609@cs.uchicago.edu> References: <4251D10C.4040508@cs.uchicago.edu> <4253114D.4050800@cs.uchicago.edu> <200504052334.09344.mark.williamson@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200504052334.09344.mark.williamson@cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Mark Williamson Cc: Ian Pratt , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Mark, Thanks for the advice. I will explicitly specify "cpu" option in domU's config file. So far, I think my experiments are not affected by this. In my experiments, I only run at most 1 domU besides dom0. I think the domU will be assigned to 2nd CPU even the assignment policy is round robin. Xuehai Mark Williamson wrote: > On Tuesday 05 April 2005 23:29, xuehai zhang wrote: > >>>I did not specify "cpu" option in Xen's configuration file, so I think >>>both dom0 and domU run on the same CPU (1st CPU). I will try to assign >>>them to different CPUs later. >> >>I think I said something wrong here. If I do not specify "cpu" option in >>Xen config file, I observe Xen usually assigns the 2nd CPU to domU while >>running dom0 on the 1st CPU. > > > Last time I looked, the default was to assign in a round robin fashion. i.e. > the next domain you create will be on the 1st CPU (with dom0) unless you > explicitly specify otherwise - watch out this doesn't confuse your testing. > > Cheers, > Mark >