Date: Thu, 17 Jun 2010 11:34:28 +0530
From: Balbir Singh <balbir@linux.vnet.ibm.com>
To: Avi Kivity <avi@redhat.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>, kvm <kvm@vger.kernel.org>,
       linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC/T/D][PATCH 2/2] Linux/Guest cooperative unmapped page cache
 control
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* Avi Kivity <avi@redhat.com> [2010-06-16 14:39:02]:

> >We're talking about an environment which we're always trying to
> >optimize.  Imagine that we're always trying to consolidate guests on to
> >smaller numbers of hosts.  We're effectively in a state where we
> >_always_ want new guests.
> 
> If this came at no cost to the guests, you'd be right.  But at some
> point guest performance will be hit by this, so the advantage gained
> from freeing memory will be balanced by the disadvantage.
> 
> Also, memory is not the only resource.  At some point you become cpu
> bound; at that point freeing memory doesn't help and in fact may
> increase your cpu load.
>

We'll probably need control over other resources as well, but IMHO
memory is the most precious because it is non-renewable. 

-- 
	Three Cheers,
	Balbir
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