Re: [libvirt-users] [API reference] confused by CPU time term
On 03/28/2012 01:44 PM, Zhihua Che wrote:
Hi, everyone
I'm writing a virtual machine monitor based on libvirt. As I read
the api reference, I found I'm confused by some terms.
1, What is cumulative I/O wait CPU time?
API reference says that VIR_NODE_CPU_STATS_IOWAIT indicate
cumulative I/O wait CPU time. I'm confused by this time. As far as I
know, when cpu meets IO wait situation, it will schedule another task,
so, how this IO wait time is accounted?
It's from /proc/stat, see man proc (/proc/stat).
2, How do I get VCPU runtime?
In my mind, VIR_DOMAIN_CPU_STATS_CPUTIME indicates the physical
cpu time consumed by the domain. Is there any API by which I can query
virtual CPU running stats in one domain?
See virDomainGetVcpus, though it doesn't returns the usertime and
systime seperately, only cputime (usertime + systime) for each
vCPU thread.
Regards,
Osier