From mboxrd@z Thu Jan  1 00:00:00 1970
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
Date: Tue, 13 Jul 2010 10:38:51 +0100
Subject: About SECTION_SIZE_BITS for Sparsemem
In-Reply-To: <20100713092852.GC29885@csn.ul.ie>
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Message-ID: <20100713093851.GE20590@n2100.arm.linux.org.uk>
To: linux-arm-kernel@lists.infradead.org
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On Tue, Jul 13, 2010 at 10:28:52AM +0100, Mel Gorman wrote:
> I like this idea. It would allow memmap_valid_within to be thrown away
> altogether and it maintains the assumptions of the memory model and
> sounds "cheap".

It can't work.  We map kernel memory with 1MB sections, not pages.