[libvirt] [PATCHv3 4/8] qemu: bulk stats: implement VCPU group

[Wang Rui]

On 2014/9/9 19:56, Peter Krempa wrote:
>> + * VIR_DOMAIN_STATS_VCPU: Return virtual CPU statistics.
>> > + * Due to VCPU hotplug, the vcpu.<num>.* array could be sparse.
>> > + * The actual size of the array correspond to "vcpu.current".
>> > + * The array size will never exceed "vcpu.maximum".
>> > + * The typed parameter keys are in this format:
>> > + * "vcpu.current" - current number of online virtual CPUs as unsigned int.
>> > + * "vcpu.maximum" - maximum number of online virtual CPUs as unsigned int.
>> > + * "vcpu.<num>.state" - state of the virtual CPU <num>, as int
>> > + *                      from virVcpuState enum.
>> > + * "vcpu.<num>.time" - virtual cpu time spent by virtual CPU <num>
>> > + *                     as unsigned long long.
>> > + * "vcpu.<num>.cpu" - physical CPU pinned to virtual CPU <num> as int.
> This is not the CPU number the vCPU is pinned to but rather the current
> CPU number where the vCPU is actually running. If you pin it to multiple
> CPUs this may change in the range of the host CPUs the vCPU is pinned
> to. Said this I don't think this is an useful stat.
> 
> Rather than this I'd like to see the mask of the host CPUs where this
> vCPU is pinned to. (returned as a human readable bitmask string).
> 
> Any thoughts?

IMO giving the vcpu's pininfo is more useful than the current pcpu number on which
vcpu is running *now*. (I don't know the requirement of management very well.)
But if it means the pininfo, what about naming it "vcpu.<num>.pin" or other
name which is less confusing?