On Wed, 2015-02-25 at 15:20 +0000, Daniel P. Berrange wrote: > On Wed, Feb 25, 2015 at 03:13:36PM +0000, Ian Campbell wrote: > > On Wed, 2015-02-25 at 15:03 +0000, Daniel P. Berrange wrote: > > > FWIW, this code in openstack was only added for benefit of s390 > > > architecture where apparently it is common to have hosts with > > > CPUs offlined. Presumably you have to pay IBM for each extra > > > CPU you turn online :) > > > > Presumably :-) > > > > OOI, why does the code care which CPUs are online rather than just the > > total number (IOW why a bitmap)? > > When doing strict CPU pinning,the openstack scheduler needs to have the > list of all pCPUs available in the host. It then tries to place guests > on pCPUs such that the guest does not span across NUMA nodes. To do this > it needs to know which particular pCPUs in the host are available. So we > need the full bitmap rather than just a total count.
Makes perfect sense, thanks. Ian. -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
