From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: Unable to set dom0 vcpu to 1 Date: Thu, 15 Jun 2006 11:16:20 -0500 Message-ID: <20060615161620.GF1694@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 [2006-06-15 10:12]: > Thanks Ryan, > > We're still seeing this problem as of changeset 10333 (which I believe > includes that patch). Yeah, that was a long shot. > > It seems as if the "vcpus" value as shown by "xm list --long 0" command > is getting set to 8, even when we boot dom0 with 16procs. In fact, vcpus > is still set to 8 even if we boot hyperthreaded to a 32x. Since the > release of procs with vcpu-set seems to key off this value, we can never > release more than 7. the vcpus value for dom0 should be the number of vcpus the domain is configured to use; usually in the conf file. Domain0 is different since it has no conf file being built by xen instead of Xend. In this case, vcpus value is derived from max_vcpu_id, which is the highest vcpu that as been initialized. For dom0, this value should be the number of cpus xen enabled during boot. vcpu-set uses the vcpu_avail variable which is initialized from the vcpus variable, which, as mentioned able is determined by max_vcpu_id. e.g. max_vcpu_id=7, vcpus = 8, vcpu_avail = (1 << 8)-1, or 0xff I'd start fresh by clearing out xenstore: rm /var/lib/xenstored/tdb And rebooting. It should never be the case where vcpus for dom0 is < online vcpus as that means you are running vcpus that haven't been initialized (max_vcpu_id indicates the max vcpu that has been allocated to run in the domain). It would be interesting if you can track what steps you took to get the machine/xenstore into this state and file a bug. -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx (512) 838-9253 T/L: 678-9253 ryanh@us.ibm.com