Re: [libvirt] [PATCHv3 4/8] qemu: bulk stats: implement VCPU group
----- Original Message -----
From: "Peter Krempa" <pkrempa(a)redhat.com>
To: "Francesco Romani" <fromani(a)redhat.com>, 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,
--
Francesco Romani
RedHat Engineering Virtualization R & D
Phone: 8261328
IRC: fromani