On Fri, Jul 22, 2016 at 05:14:33PM +1000, David Gibson wrote: > On Fri, Jul 22, 2016 at 11:40:03AM +0530, Bharata B Rao wrote: > > On Fri, Jul 22, 2016 at 01:23:01PM +1000, David Gibson wrote: > > > On Thu, Jul 21, 2016 at 05:54:37PM +0200, Igor Mammedov wrote: > > > > It will enshure that cpu_index for a given cpu stays the same > > > > regardless of the order cpus has been created/deleted and so > > > > it would be possible to migrate QEMU instance with out of order > > > > created CPU. > > > > > > > > Signed-off-by: Igor Mammedov <imamm...@redhat.com> > > > > > > So, this isn't quite right (it wasn't right in my version either). > > > > > > The problem occurs when smp_threads < kvmppc_smt_threads(). That is, > > > when the requested threads-per-core is less than the hardware's > > > maximum number of threads-per-core. > > > > > > The core-id values are assigned essentially as i * > > > kvmppc_smt_threads(), meaning the patch below will leave gaps in the > > > cpu_index values and the last ones will exceed max_cpus, causing other > > > problems. > > > > This would lead to hotplug failures as cpu_dt_id is still being > > derived from non-contiguous cpu_index resulting in wrong enumeration > > of CPU nodes in DT. > > Which "This" are you referring to?
:) Gaps in cpu_index values due to which cpu_dt_id gets calculated wrongly. Regards, Bharata.
