Re: [kvm-devel] Réf. : Re: [PATCH 0 /4] Virtual Machine Time Accounting

[Glauber de Oliveira Costa]

On 8/21/07, Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
> Am Montag, 20. August 2007 schrieb Glauber de Oliveira Costa:
> > Although I don't know KVM to a that deep level, I think it should be
> > possible to keep the virtual cpus in different process (or threads),
> > and take the accounting time from there. Perfectly possible to know
> > the time we spent running (user time), and the time the hypervisor
> > spent doing things on our behalf (system time).
>
> I disagree here. First thing, you dont want to have the virtual cpu in a
> different process than the hypervisor control code for that cpu. Otherwise
> communication has to be made via IPC.
> Secondly, Its not qemu/kvm that does the accouting. Its existing userspace
> code like top/snmp agents and clients! etc. that would require additional
> knowledge which thread is guest code.

Yes, the second argument kills me, and I think it leaves no further
room from discussion in my side. Thanks for the enlightenment.

> I personally like the approach Laurent has taken. Maybe it needs some polish
> and maybe we want an account_guest_time function, but in general I think he
> is doing the right thing.
>
Now, me too.

-- 
Glauber de Oliveira Costa.
"Free as in Freedom"
http://glommer.net

"The less confident you are, the more serious you have to act."
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