[RFC PATCH] ARM: Consider memblocks in mem_init and show_mem.

[Russell King - ARM Linux]

On Wed, Dec 12, 2012 at 05:40:00PM +0000, Steve Capper wrote:
> One consequence of using memblocks in show_mem, is that we are
> unable to define ARCH_DISCARD_MEMBLOCK.

That's true anyway, because we use it for pfn_valid(), which gets used
for ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM.