Re: [libvirt] [PATCH] bhyve: implement domainGetCPUStats

On 04/30/2014 12:03 PM, Daniel P. Berrange wrote: > On Tue, Apr 29, 2014 at 08:54:26PM +0400, Roman Bogorodskiy wrote: >> >> 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. > The apps should check how many stat parameters are supported for a given pCPU by calling virDomainGetCPUStats with nparams=0 and/or check the actual number of stats returned. Could we return valid results for total CPU stats (start_cpu = -1) and just not return any for all other start_cpu values?