Re: cputime takes cstate into consideration

[Wanpeng Li]

also Cc Frederic,
On Tue, 9 Jul 2019 at 10:00, Ankur Arora <ankur.a.arora@xxxxxxxxxx> wrote:
>
> On 2019-06-26 12:23 p.m., Thomas Gleixner wrote:
> > On Wed, 26 Jun 2019, Raslan, KarimAllah wrote:
> >> On Wed, 2019-06-26 at 10:54 -0400, Konrad Rzeszutek Wilk wrote:
> >>> There were some ideas that Ankur (CC-ed) mentioned to me of using the perf
> >>> counters (in the host) to sample the guest and construct a better
> >>> accounting idea of what the guest does. That way the dashboard
> >>> from the host would not show 100% CPU utilization.
> >>
> >> You can either use the UNHALTED cycles perf-counter or you can use MPERF/APERF
> >> MSRs for that. (sorry I got distracted and forgot to send the patch)
> >
> > Sure, but then you conflict with the other people who fight tooth and nail
> > over every single performance counter.
> How about using Intel PT PwrEvt extensions? This should allow us to
> precisely track idle residency via just MWAIT and TSC packets. Should
> be pretty cheap too. It's post Cascade Lake though.
>
> Ankur
>
> >
> > Thanks,
> >
> >       tglx
> >
>