> -----Original Message----- > From: Michal Privoznik [mailto:mprivozn@xxxxxxxxxx] > Sent: Friday, April 19, 2013 10:53 PM > To: Wangkai (Kevin,C) > Cc: libvirt-users@xxxxxxxxxx > Subject: Re: problem when get the vm cpu stat > > On 19.04.2013 09:40, Wangkai (Kevin,C) wrote: > > Hi all, > > > > > > > > I try to get vm cpu stat by function "virDomainGetCPUStats", when > the vm > > > > > > > > Cpu usage is 100%, I can see from the vm shell by "top", when the > info > > > > > > > > Get by the "virDomainGetCPUStats" show only the "cpu_time" increased, > > > > > > > > "user_time" and "system_time" was not changed at all. > > > > > > > > Is that correct ? How can I get the vm cpu usage? > > > > > > > > nparams = virDomainGetCPUStats(domain, NULL, 0, -1, 1, 0); > > > > virDomainGetCPUStats(domain, params, nparams, -1, 1, 0); > > You can gather statistics in similar way that 'top' does. Query current > usage in loops and divide increment by time. Something like: > > > nparams = virDomainGetCPUStats(domain, NULL, 0, -1, 1, 0); > > while (1) { > struct timeval now, then; > int i, j; > > gettimeofday(&now, NULL); > virDomainGetCPUStats(domain, params_now, nparams, -1, 1, 0); > > /* some sleep, e.g. 500ms */ > usleep(5000); > > virDomainGetCPUStats(domain, params_then, nparams, -1, 1, 0); > gettimeofday(&then, NULL); > > /* find appropriate i and j */ > > /* virDomainGetCPUStats is returning time in microseconds IIRC */ > float usage_in_percent = (params_then[i] - params_now[j]) / > (then.tv_usec - now.tv_usec) / 1000; > > printf("%f\n", usage_in_percent); > } [Wangkai (Kevin,C)] Thank you, I will do this way. _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
