From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave Hansen <dave@linux.vnet.ibm.com>
Subject: Re: [linux-pm] [PATCH] hibernation should work ok with memory
	hotplug
Date: Wed, 05 Nov 2008 08:23:43 -0800
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To: Nigel Cunningham <ncunningham@crca.org.au>
Cc: Matt Tolentino <matthew.e.tolentino@intel.com>, linux-pm@lists.osdl.org, Dave Hansen <haveblue@us.ibm.com>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, pavel@suse.cz, Mel Gorman <mel@skynet.ie>, Andy Whitcroft <apw@shadowen.org>, Andrew Morton <akpm@linux-foundation.org>
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On Wed, 2008-11-05 at 20:10 +1100, Nigel Cunningham wrote:
> In your example above, zone_start_pfn will be 1, won't it? If that's the
> case, I shouldn't need to subtract ARCH_PFN_OFFSET to get the right
> index within the zone and avoid the same wastage that ARCH_PFN_OFFSET
> avoids with mem_map.

Yeah, I don't think the first zone will ever start before
ARCH_PFN_OFFSET.

If the code just deals with starting at any random zone_start_pfn and
going to any other random zone_end_pfn without any waste, then it should
be fine in the presence of ARCH_PFN_OFFSET.  The only trouble is if it
assumes memory to start at 0x0.

-- Dave