Align virtual memoryu map to MAX_ORDER boundary

This avoids calling pfn_valid and its easy to do given the virtual
nature of the memory map.

Signed-off-by: Christoph Lameter <clameter@sgi.com

Index: linux-2.6.18-mm3/arch/ia64/mm/init.c
===================================================================
--- linux-2.6.18-mm3.orig/arch/ia64/mm/init.c	2006-10-06 21:02:12.501988330 -0700
+++ linux-2.6.18-mm3/arch/ia64/mm/init.c	2006-10-06 21:17:26.089195607 -0700
@@ -482,8 +482,15 @@ create_mem_map_page_table (u64 start, u6
 	pmd_t *pmd;
 	pte_t *pte;
 
-	map_start = virt_to_page(start);
-	map_end   = virt_to_page(end);
+	/*
+	 * The virtual memory map must go to the MAX_ORDER_NR boundary
+ 	 * in order to allow the page allocator to do its buddy
+	 * checks correctly.
+	 */
+	map_start = pfn_to_page((__pa(start) >> PAGE_SHIFT) &
+					 ~(MAX_ORDER_NR_PAGES - 1));
+	map_end   = pfn_to_page(ALIGN(__pa(end) >> PAGE_SHIFT,
+				MAX_ORDER_NR_PAGES));
 
 	start_page = (unsigned long) map_start & PAGE_MASK;
 	end_page = PAGE_ALIGN((unsigned long) map_end);
Index: linux-2.6.18-mm3/mm/page_alloc.c
===================================================================
--- linux-2.6.18-mm3.orig/mm/page_alloc.c	2006-10-06 20:41:58.593416489 -0700
+++ linux-2.6.18-mm3/mm/page_alloc.c	2006-10-06 21:09:02.755981924 -0700
@@ -154,7 +154,7 @@ static int page_outside_zone_boundaries(
 
 static int page_is_consistent(struct zone *zone, struct page *page)
 {
-#ifdef CONFIG_HOLES_IN_ZONE
+#if !defined(VIRTUAL_MEM_MAP) && defined(CONFIG_HOLES_IN_ZONE)
 	if (!pfn_valid(page_to_pfn(page)))
 		return 0;
 #endif
@@ -359,7 +359,7 @@ __find_combined_index(unsigned long page
 static inline int page_is_buddy(struct page *page, struct page *buddy,
 								int order)
 {
-#ifdef CONFIG_HOLES_IN_ZONE
+#if !defined(VIRTUAL_MEM_MAP) && defined(CONFIG_HOLES_IN_ZONE)
 	if (!pfn_valid(page_to_pfn(buddy)))
 		return 0;
 #endif