page_alloc.c contains a large amount of memory initialisation code. This patch
breaks out the initialisation code to a separate file to make page_alloc.c
a bit easier to read.
+/*
+ * mm/mem_init.c
+ * Initialises the architecture independant view of memory. pgdats, zones, etc
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ * Swap reorganised 29.12.95, Stephen Tweedie
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
+ * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
+ * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
+ * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
+ * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
+ * Arch-independant zone size and hole calculation, Mel Gorman, IBM, Apr 2006
+ * (lots of bits taken from architecture code)
+ */