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Date: Mon, 7 Feb 2011 16:50:02 +0000
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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To: Yinghai Lu <yinghai@kernel.org>
CC: "H. Peter Anvin" <hpa@zytor.com>, Jeremy Fitzhardinge <jeremy@goop.org>,
        Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>,
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        "x86@kernel.org" <x86@kernel.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Jan Beulich <JBeulich@novell.com>
Subject: Re: [PATCH] x86/mm/init: respect memblock reserved regions when
 destroying mappings
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On Sun, 6 Feb 2011, Yinghai Lu wrote:
> On 02/05/2011 11:30 PM, H. Peter Anvin wrote:
> > On 02/05/2011 11:02 PM, Yinghai Lu wrote:
> >> why not just move calling cleanup_highmap down?
> >>
> >> something like attached patch.
> > 
> > This patch looks very clean and looks on the surface of it like it is
> > removing some ugly ad hoc code, but (as always) it needs a description
> > about the problem it solves and why it is correct.
> 
> Sure.
> 
> 
> Jeremy and xen guys, can you please check if it works well with xen ?
> 

Actually this patch makes things worse on xen, because before
cleanup_highmap() wasn't called at all on xen (on purpose) and now it
is, fully destroying all the mappings we have at _end.

Can we add a check on memblock reserved regions in cleanup_highmap()?
Otherwise could we avoid calling cleanup_highmap() at all on xen?