From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: Unable to set dom0 vcpu to 1 Date: Mon, 12 Jun 2006 10:11:53 -0500 Message-ID: <20060612151153.GA1694@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: "Carb, Brian A" Cc: xen-devel@lists.xensource.com, "McAfee, Tommie M" , "Krysan, Susan" , "Puthiyaparambil, Aravindh" , "Subrahmanian, Raj" , "Vessey, Bruce A" List-Id: xen-devel@lists.xenproject.org * Carb, Brian A [2006-06-08 15:13]: > > Running xen-unstable changeset 10269 on a Unisys ES7000/one, x86_64, > > 16 procs, 16 GB RAM under SLES 10 RC1. > > > > At startup, dom0-cpus is set to 0 (the default) in the xend-config.sxp > > file, and dom0 uses all 16 cpus. 'xm top' shows 16 procs, 'xm list' > > shows dom0 using 16 cpus, and 'xm vcpu-list' shows 16 cpus assigned to > > dom0. > > > > When we try to reduce the procs for dom0 to 1 using 'xm vcpu-set 0 1', > > the number of procs, as shown by /proc/cpuinfo, reduces to 9. 'xm > > list' shows dom0 using 9 procs, and 'xm vcpu-list' shows that procs > > 1-7 have been released, while procs 0 and 8 through 15 are still > > assigned. Nothing is shown on the serial port. > > > > Can anyone shed some light on why the rest of the procs might not be > > released? Thanks. On large smp boxes, it takes some time to unplug all of the processors as any processes that are running on those cpus have to be migrated to another cpu. On a 32-way, it took 15 seconds to go from 32 to 1. As I ran xm list, you can see the number of active vcpus reduce over time. [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 21 r----- 4494.6 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 19 r----- 4495.4 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 17 r----- 4496.2 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 16 r----- 4496.8 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 16 r----- 4497.4 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 15 r----- 4497.6 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 14 r----- 4498.1 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 13 r----- 4498.6 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 12 r----- 4499.2 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 12 r----- 4499.4 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 10 r----- 4500.3 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 10 r----- 4500.7 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 9 r----- 4501.0 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 8 r----- 4501.5 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 7 r----- 4502.0 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 6 r----- 4502.5 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 4 r----- 4503.4 [root@x460-3 ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 507 1 r----- 4504.4 -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx (512) 838-9253 T/L: 678-9253 ryanh@us.ibm.com