[libvirt] [PATCHv2 3/3] virsh: Use virNodeGetCPUMap if possible

Viktor Mihajlovski mihajlov at linux.vnet.ibm.com
Thu Nov 1 15:53:34 UTC 2012

On 11/01/2012 02:06 PM, Eric Blake wrote:
> On 11/01/2012 02:05 AM, Viktor Mihajlovski wrote:
>> But that would
>> be semantically incorrect as the field is denominated as the number of
>> active CPUs. Fixing the core/socket/thread detection doesn't seem
>> possible using the sysfs interfaces.
> Why not?  We just proved with nodeGetCPUCount that it is possible to
> determine the number of possible cpus even when some of the
> cores/threads are offline.  That just means our core/socket/thread
> detection code needs to be aware of offline cpus, even if it can't
> determine their complete topology, so that it at least doesn't
> underestimate the number of possible cores.
Well, with offline CPUs we would be forced to guess the topology in a 
worst case manner (i.e. does the offline CPU add a new socket, core or 
thread), which will result in a too high VIR_NODEINFO_MAXCPUS value.
I haven't thought through the consequences of that, though...


Mit freundlichen Grüßen/Kind Regards
    Viktor Mihajlovski

IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter
Geschäftsführung: Dirk Wittkopp
Sitz der Gesellschaft: Böblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294

More information about the libvir-list mailing list