From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: Setting dom0-cpus to 0 doesn't use all cpus asdocumented Date: Tue, 9 May 2006 10:44:45 -0500 Message-ID: <20060509154445.GG28945@us.ibm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Pratt Cc: Xen-devel@lists.xensource.com, "Krysan, Susan" , "Puthiyaparambil, Aravindh" , "Subrahmanian, Raj" , "Vessey, Bruce A" , "Carb, Brian A" List-Id: xen-devel@lists.xenproject.org * Ian Pratt [2006-05-09 10:07]: > > The comments for dom0-cpus in the xend-config.sxp file > > indicate that setting this value to 0 in an SMP system will > > cause dom0 to use all the available CPUs. However, it appears > > as if setting this value to 0 does not change the number of > > CPUs at all. > > > > I'm running SLES10 Beta 11 and xen-unstable changeset 9960 on > > a Unisys ES7000 with 32 CPUs and 32GB memory. In > > xend-config.sxp, dom0-cpus is set to 0. When xen dom0 boots, > > it is using all 32 procs (as reported by 'grep processor > > /proc/cpuinfo | wc -l'). > > > > If I edit the xend-config.sxp file, change the value of > > dom0-cpus to 1, and restart xend, dom0 correctly uses 1 CPUs. > > If I then change dom0-cpus to 0 and restart xend, dom0 still > > uses 1 cpu. The only way to have dom0 use 32 cpus again is to > > either set the value of dom0-cpus to 32, or reboot xen. > > > > Has anyone else seen this behavior? > > You can just use the normal xm commands to vary the number of CPUs. > Restarting xend is a rather brutal way of trying to achieve the same > thing... Is it worth keeping dom0-cpus then? -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx (512) 838-9253 T/L: 678-9253 ryanh@us.ibm.com