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

----- Original Message ----- > From: "Peter Krempa" <pkrempa(a)redhat.com&gt; > To: "Francesco Romani" <fromani(a)redhat.com&gt;, libvir-list(a)redhat.com > Sent: Tuesday, September 9, 2014 1:56:09 PM > Subject: Re: [libvirt] [PATCHv3 4/8] qemu: bulk stats: implement VCPU group >> + * 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. Right, my bad, I overlooked the docs (started to suspect when saw it changing too often in my tests..). I agree this is not very useful, I'll drop it. > 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? Is that the data provided by http://libvirt.org/html/libvirt-libvirt.html#virDomainGetVcpuPinInfo it isn't? (I'm asking because docs aren't crystal clear for me).

I like this, but I'd also need to do a cross-check on my our code in oVirt. Will be acceptable to drop the misleading vcpu.<num>.cpu info and to add the pin info in a new followup patch, in this stats group?

Bests,