Message-ID: <489B84EF.6050009@kernel.org>
Date: Thu, 07 Aug 2008 16:27:43 -0700
From: "H. Peter Anvin" <hpa@kernel.org>
Organization: Linux Kernel Organization, Inc.
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To: Jeremy Fitzhardinge <jeremy@goop.org>
CC: Zachary Amsden <zach@vmware.com>, Alok Kataria <akataria@vmware.com>,
       "torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
       Ingo Molnar <mingo@elte.hu>, the arch/x86 maintainers <x86@kernel.org>,
       LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH]Fix broken VMI in 2.6.27-rc..
References: <1218136365.23770.52.camel@alok-dev1>	 <489B6710.9000604@kernel.org> <1218144438.20178.336.camel@bodhitayantram.eng.vmware.com> <489B836A.3050209@goop.org>
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Jeremy Fitzhardinge wrote:
> Zachary Amsden wrote:
>> Or we could remove the dependency on max_low_pfn and just create a
>> liberal linear to physical mapping for lomem which spans all possible
>> low memory; then it doesn't matter so much where it is called.
>>   
> 
> Yes.  You could just call reserve_top_address() at a suitably early 
> point to reserve the space.  Its a pvops API call which has been there 
> since patch one or two of pvops.
> 
> It does exactly what the rest of this thread discusses, rendering it moot.

It's not moot.

The fixmap area should never have been made movable.  It's utter 
braindamage.

Given the x86 architecture, it's inevitable that PV will want to reserve 
address space at the top of memory, and therefore the fixmap area needs 
to be moved out of that space.

	-hpa
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