Index: linux-2.6.18-mm3/arch/x86_64/Kconfig
===================================================================
--- linux-2.6.18-mm3.orig/arch/x86_64/Kconfig	2006-10-04 21:39:45.000000000 -0700
+++ linux-2.6.18-mm3/arch/x86_64/Kconfig	2006-10-04 21:41:32.000000000 -0700
@@ -105,6 +105,10 @@
 	default y
 	depends on BUG
 
+config VIRTUAL_MEM_MAP
+	bool
+	default y
+
 source "init/Kconfig"
 
 
@@ -362,10 +366,6 @@
 	def_bool y
 	depends on NUMA
 
-config ARCH_SPARSEMEM_ENABLE
-	def_bool y
-	depends on (NUMA || EXPERIMENTAL)
-
 config ARCH_MEMORY_PROBE
 	def_bool y
 	depends on MEMORY_HOTPLUG
Index: linux-2.6.18-mm3/arch/x86_64/mm/init.c
===================================================================
--- linux-2.6.18-mm3.orig/arch/x86_64/mm/init.c	2006-10-04 21:43:10.000000000 -0700
+++ linux-2.6.18-mm3/arch/x86_64/mm/init.c	2006-10-04 22:06:41.000000000 -0700
@@ -567,6 +567,10 @@
 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 
+#ifdef CONFIG_VIRTUAL_MEM_MAP
+	mem_map = (struct page *)VMEMMAP_START;
+	max_mapnr = MAX_MEM >> PAGE_SIZE;
+#endif
 	/* Register memory areas for /proc/kcore */
 	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 
 	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 
Index: linux-2.6.18-mm3/arch/x86_64/mm/numa.c
===================================================================
--- linux-2.6.18-mm3.orig/arch/x86_64/mm/numa.c	2006-10-04 21:41:40.000000000 -0700
+++ linux-2.6.18-mm3/arch/x86_64/mm/numa.c	2006-10-04 22:08:36.000000000 -0700
@@ -93,13 +93,6 @@
 	return shift;
 }
 
-#ifdef CONFIG_SPARSEMEM
-int early_pfn_to_nid(unsigned long pfn)
-{
-	return phys_to_nid(pfn << PAGE_SHIFT);
-}
-#endif
-
 static void * __init
 early_node_mem(int nodeid, unsigned long start, unsigned long end,
 	      unsigned long size)
@@ -174,6 +167,7 @@
 /* Initialize final allocator for a zone */
 void __init setup_node_zones(int nodeid)
 { 
+#ifndef CONFIG_VIRTUAL_MEM_MAP
 	unsigned long start_pfn, end_pfn, memmapsize, limit;
 
  	start_pfn = node_start_pfn(nodeid);
@@ -193,6 +187,7 @@
 				round_down(limit - memmapsize, PAGE_SIZE), 
 				limit);
 #endif
+#endif
 } 
 
 void __init numa_init_array(void)
@@ -321,33 +316,17 @@
 	return pages;
 } 
 
-#ifdef CONFIG_SPARSEMEM
-static void __init arch_sparse_init(void)
-{
-	int i;
-
-	for_each_online_node(i)
-		memory_present(i, node_start_pfn(i), node_end_pfn(i));
-
-	sparse_init();
-}
-#else
-#define arch_sparse_init() do {} while (0)
-#endif
-
 void __init paging_init(void)
 { 
 	int i;
 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { MAX_DMA_PFN,
 		MAX_DMA32_PFN,
 		end_pfn};
-
-	arch_sparse_init();
-
+#ifndef CONFIG_VIRTUAL_MEM_MAP
 	for_each_online_node(i) {
 		setup_node_zones(i); 
 	}
-
+#endif
 	free_area_init_nodes(max_zone_pfns);
 } 
 
Index: linux-2.6.18-mm3/include/asm-x86_64/pgtable.h
===================================================================
--- linux-2.6.18-mm3.orig/include/asm-x86_64/pgtable.h	2006-10-04 21:33:44.000000000 -0700
+++ linux-2.6.18-mm3/include/asm-x86_64/pgtable.h	2006-10-04 21:38:10.000000000 -0700
@@ -130,7 +130,12 @@
 
 #ifndef __ASSEMBLY__
 #define MAXMEM		 0x3fffffffffffUL
+#define VMEMMAP_START	 0xffff000000000000UL
+#define VMMEMAP_SIZE	 (MAX_MEM << PAGE_SIZE * sizeof(struct page))
 #define VMALLOC_START    0xffffc20000000000UL
+#if (VMALLOC_START > VMMEMAP_START + VMEMMAP_START)
+#error Virtual mem_map reaches into VMALLOC area
+#endif
 #define VMALLOC_END      0xffffe1ffffffffffUL
 #define MODULES_VADDR    0xffffffff88000000UL
 #define MODULES_END      0xfffffffffff00000UL
Index: linux-2.6.18-mm3/mm/page_alloc.c
===================================================================
--- linux-2.6.18-mm3.orig/mm/page_alloc.c	2006-10-04 22:11:03.000000000 -0700
+++ linux-2.6.18-mm3/mm/page_alloc.c	2006-10-04 22:14:36.000000000 -0700
@@ -2540,7 +2540,7 @@
 	if (!pgdat->node_spanned_pages)
 		return;
 
-#ifdef CONFIG_FLAT_NODE_MEM_MAP
+#if defined(CONFIG_FLAT_NODE_MEM_MAP) && !defined(CONFIG_VIRTUAL_MEM_MAP)
 	/* ia64 gets its own node_mem_map, before this, without bootmem */
 	if (!pgdat->node_mem_map) {
 		unsigned long size, start, end;
@@ -2560,7 +2560,7 @@
 			map = alloc_bootmem_node(pgdat, size);
 		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
 	}
-#ifdef CONFIG_FLATMEM
+#if defined(CONFIG_FLATMEM) && !defined(CONFIG_VIRTUAL_MEM_MAP)
 	/*
 	 * With no DISCONTIG, the global mem_map is just set as node 0's
 	 */