From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: Does dom0 see all physical processors? (RE: [Xen-ia64-devel] SAL INFO virtualization) Date: Fri, 7 Apr 2006 10:42:09 -0500 Message-ID: <20060407154209.GA16776@us.ibm.com> References: <516F50407E01324991DD6D07B0531AD5AA8E66@cacexc12.americas.cpqcorp.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <516F50407E01324991DD6D07B0531AD5AA8E66@cacexc12.americas.cpqcorp.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Magenheimer, Dan (HP Labs Fort Collins)" Cc: "Tian, Kevin" , xen-devel , Orran Krieger , Tristan Gingold , xen-ia64-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org * Magenheimer, Dan (HP Labs Fort Collins) [2006-04-07 01:43]: > I understand and sympathize with the need for dom0 to > sometimes get and use information from each processor > that is only available if dom0 is running on each processor. > > However, AFAIK, SMP guests are always gang-scheduled, correct? I don't believe either the bvt or sedf scheduler in Xen provide any gang scheduling support. Each physical cpu has its own runqueue and it schedules VCPUs independently. The scheduling parameters are set on a per-domain basis but end up being the same for each VCPU. -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx (512) 838-9253 T/L: 678-9253 ryanh@us.ibm.com