[libvirt] [PATCH] bhyve: implement domainGetCPUStats

[Daniel P. Berrange]

On Tue, Apr 29, 2014 at 08:54:26PM +0400, Roman Bogorodskiy wrote:
>   Ján Tomko wrote:
> 
> > On 04/24/2014 11:14 AM, Roman Bogorodskiy wrote:
> > >   Ján Tomko wrote:
> > > 
> > >> On 04/22/2014 07:44 PM, Roman Bogorodskiy wrote:
> > >>> For per CPU stats, implement virBhyveGetDomainPercpuStats() that
> > >>> uses bhyvectl tool to obtain the guest's vcpu stats.
> > >>>
> > >>
> > >> In virDomainGetCPUStats API, the start_cpu and ncpus parameters refer to host
> > >> CPUs, not the vcpus.
> > > 
> > > Looks like I misunderstood the API. :-(
> > > 
> > > In other words, this API operates with the host CPUs? So if user calls
> > > it with e.g. start_cpu = 2 and ncpus = 2, I should return info on how
> > > much time host CPUs 2 and 3 spend on the given domain (as the opposite
> > > to how much time domain's vcpu 2 and vcpu 3 were busy)?
> > > 
> > 
> > Yes.
> > 
> > Jan
> > 
> 
> Looks like FreeBSD does not support such kind of per-cpu reporting for
> host cpus. Just to make sure I didn't miss something, I asked that
> question of the FreeBSD virtualization maillist and looks like I'm right
> about that [1].
> 
> Would it better to abandon this feature for now and wait when it'd be
> supported (I'm not sure if/when it's going to happen), or just leave the
> code that reports only the stats for all cpus?

I think it is better to leave it unsupported, so apps can see the
VIR_ERR_NO_SUPPORT error and not mistakenly interpret incorrect data.


Regards,
Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|