From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chris Wright <chrisw@sous-sol.org>
Subject: Re: [PATCH] kvm-vmx: add module parameter to avoid trapping HLT
 instructions (v2)
Date: Fri, 3 Dec 2010 09:28:25 -0800
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Cc: Chris Wright <chrisw@sous-sol.org>,
	Anthony Liguori <aliguori@us.ibm.com>, kvm@vger.kernel.org,
	Avi Kivity <avi@redhat.com>,
	Marcelo Tosatti <mtosatti@redhat.com>
To: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
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* Srivatsa Vaddagiri (vatsa@linux.vnet.ibm.com) wrote:
> On Thu, Dec 02, 2010 at 11:14:16AM -0800, Chris Wright wrote:
> > Perhaps it should be a VM level option.  And then invert the notion.
> > Create one idle domain w/out hlt trap.  Give that VM a vcpu per pcpu
> > (pin in place probably).  And have that VM do nothing other than hlt.
> > Then it's always runnable according to scheduler, and can "consume" the
> > extra work that CFS wants to give away.
> 
> That's not sufficient. Lets we have 3 guests A, B, C that need to be
> rate limited to 25% on a single cpu system. We create this idle guest
> D that is 100% cpu hog as per above definition. Now when one of the
> guest is idle, what ensures that the idle cycles of A is given only
> to D and not partly to B/C?

Yeah, I pictured priorties handling this.