Date: Fri, 9 Jul 2010 19:32:56 +0200
From: Daniel Kiper <dkiper@net-space.pl>
To: Andi Kleen <andi@firstfloor.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>, Daniel Kiper <dkiper@net-space.pl>,
       xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org
Subject: Re: [Xen-devel] Re: GSoC 2010 - Migration from memory ballooning to	memory hotplug in Xen
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References: <20100708194553.GA30124@router-fw-old.local.net-space.pl> <871vbdr4ey.fsf@basil.nowhere.org> <4C36648F.6020006@goop.org> <20100709003409.GC15950@basil.fritz.box>
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On Fri, Jul 09, 2010 at 02:34:09AM +0200, Andi Kleen wrote:
> > > The only advantage of using memory hotadd is that the mem_map doesn't
> > > need to be pre-allocated, but that's only a few percent of the memory.
> > >
> > > So it would only help if you want to add gigantic amounts of memory
> > > to a VM (like >20-30x of what it already has).
> >
> > That's not wildly unreasonable on the face of it; consider a domain
> > which starts at 1GB but could go up to 32GB as demand requires.  But
>
> The programs which need 32GB will probably not even start in 1GB :)

I am able to run program which allocates 32GB on machine 1GB... :-)))
Do not underestimate memory overcommit...

Daniel
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