[Fedora-it] Re: [fedora-virt] Virtualization: qemu-kvm: Excessive CPU usage on host

[Dario Lesca]

Il giorno mar, 15/12/2009 alle 12.46 -0600, Justin M. Forbes ha scritto:
> On Tue, 2009-12-15 at 19:31 +0100, Dario Lesca wrote:
> > Il giorno mar, 15/12/2009 alle 11.28 -0600, Justin M. Forbes ha scritto:
> > > 
> > > > Is this normal? 
> > > KSM has a penalty in that it requires CPU cycles to scan for usable
> > > pages.
> > 
> > > This should be mitigated by the ksm service turning the scanner off
> > > when it is not needed.
> > > Do you have any more information on the hardware profile? Is there a
> > > smolt profile for this system?
> > 
> > Yes :
> >         http://www.smolts.org/client/show_all/pub_9da3c016-41da-42f1-b2c3-05f31ffb88f5
> > 
> > > > It's possible do something to improve the situation? 
> > > Is the ksmtuned service running? 
> > Yes:
> >         [root a lesca ~]# /etc/init.d/ksmtuned status
> >         ksmtuned (pid  1522) in esecuzione...
> > 
> > 
> > > If not, please turn it on.  Optionally you can also turn off ksm and
> > > ksmtuned.
> > 
> > I have turn off ksm and ksmtuned but the qemu use always 15% cpu... none
> > is changed.
> 
> This is most likely an manifestation of
> https://bugzilla.redhat.com/show_bug.cgi?id=478317 and hopefully we will
> have a fix soon.

OK, I'll wait!

thanks!

> thanks
> Justin
> 


-- 
Dario Lesca <d.lesca a solinos.it>