Re: [PATCH v2 3/6] KVM-GST: KVM Steal time accounting

lidong chen
2011-01-30T16:45:32Z

I think we can use performance counter.
use unhalted core cycles event, in the nmi callback funcation, count
which process is running .
if the vm exit is caused by nmi,discard it.
the system time of qemu process is the time steal by kvm.

2011/1/30 Avi Kivity <avi@redhat.com>:
> On 01/28/2011 09:52 PM, Glauber Costa wrote:
>>
>> This patch accounts steal time time in kernel/sched.
>> I kept it from last proposal, because I still see advantages
>> in it: Doing it here will give us easier access from scheduler
>> variables such as the cpu rq. The next patch shows an example of
>> usage for it.
>>
>> Since functions like account_idle_time() can be called from
>> multiple places, not only account_process_tick(), steal time
>> grabbing is repeated in each account function separatedely.
>>
>
> I accept that steal time is worthwhile, but do you have some way to
> demonstrate that the implementation actually works and is beneficial?
>
> Perhaps run two cpu-bound compute processes on one vcpu, overcommit that
> vcpu, and see what happens to the processing rate with and without steal
> time accounting.  I'd expect a fairer response with steal time accounting.
>
> --
> error compiling committee.c: too many arguments to function
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>