Index: linux-2.6/include/asm-generic/memory_model.h
===================================================================
--- linux-2.6.orig/include/asm-generic/memory_model.h	2007-03-25 20:43:22.000000000 -0700
+++ linux-2.6/include/asm-generic/memory_model.h	2007-03-25 20:45:01.000000000 -0700
@@ -47,6 +47,13 @@
 })
 
 #elif defined(CONFIG_SPARSEMEM)
+#ifdef CONFIG_VMEMMAP
+/*
+ * We have a virtual memmap that makes lookups very simple
+ */
+#define __pfn_to_page(pfn)	(vmemmap + (pfn))
+#define __page_to_pfn(page)	((page) - vmemmap)
+#else
 /*
  * Note: section's mem_map is encorded to reflect its start_pfn.
  * section[i].section_mem_map == mem_map's address - start_pfn;
@@ -62,6 +69,7 @@
 	struct mem_section *__sec = __pfn_to_section(__pfn);	\
 	__section_mem_map_addr(__sec) + __pfn;		\
 })
+#endif
 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
 
 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
Index: linux-2.6/mm/sparse.c
===================================================================
--- linux-2.6.orig/mm/sparse.c	2007-03-25 20:43:22.000000000 -0700
+++ linux-2.6/mm/sparse.c	2007-03-25 22:16:05.000000000 -0700
@@ -101,7 +101,7 @@
 
 /*
  * Although written for the SPARSEMEM_EXTREME case, this happens
- * to also work for the flat array case becase
+ * to also work for the flat array case because
  * NR_SECTION_ROOTS==NR_MEM_SECTIONS.
  */
 int __section_nr(struct mem_section* ms)
@@ -209,6 +209,89 @@
 	return 1;
 }
 
+#ifdef CONFIG_VMEMMAP
+
+unsigned long vmemmap_alloc_block(unsigned long size, int node)
+{
+	if (slab_is_available()) {
+		struct page *page =
+			alloc_pages_node(node, GFP_KERNEL,
+				get_order(size));
+
+		if (!page)
+			return 0;
+
+		return page_to_pfn(page) << PAGE_SHIFT;
+	} else
+		return (unsigned long)alloc_bootmem_node(NODE_DATA(node),
+								size);
+}
+
+
+#ifndef ARCH_VMEMMAP_POPULATE
+void vmemmap_populate(struct page *start_page, unsigned long nr, int node)
+#else
+/*
+ * VMEMMAP populate functionality for architectures that support
+ * PMDs for huge pages.
+ */
+static void vmemmap_pop_pmd(pud_t *pud, unsigned long addr, unsigned long end, int node)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	pmd = pmd_alloc(&init_mm, pud, addr);
+	do {
+		next = pmd_addr_end(addr, end);
+		if (pmd_none(*pmd)) {
+			unsigned long block = vmemmap_alloc_block(PMD_SIZE, node);
+			pte_t pte = pfn_pte(block >> PAGE_SHIFT, PAGE_KERNEL);
+
+			BUG_ON(!block);
+			pte_mkdirty(pte);
+			pte_mkwrite(pte);
+			pte_mkyoung(pte);
+			mk_pte_huge(pte);
+			set_pmd(pmd, __pmd(pte_val(pte)));
+		}
+		pmd++;
+		addr = next;
+	} while (addr < end);
+}
+
+static void vmemmap_pop_pud(pgd_t *pgd, unsigned long addr, unsigned long end, int node)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	pud = pud_alloc(&init_mm, pgd, addr);
+	do {
+		next = pud_addr_end(addr, end);
+		vmemmap_pop_pmd(pud, addr, next, node);
+		pud++;
+		addr = next;
+	} while (addr < end);
+}
+
+
+static void vmemmap_populate(struct page *start_page, unsigned long nr,
+								int node)
+{
+	unsigned long addr = (unsigned long)start_page;
+	unsigned long end = (unsigned long)(start_page + nr);
+	unsigned long next;
+	pgd_t *pgd;
+
+	pgd = pgd_offset_k(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		vmemmap_pop_pud(pgd, addr, end, node);
+		pgd++;
+		addr = next;
+	} while (addr < end);
+}
+#endif
+
 static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
 {
 	struct page *map;
@@ -219,8 +302,13 @@
 	if (map)
 		return map;
 
+#ifdef CONFIG_VMEMMAP
+	map = pfn_to_page(pnum * PAGES_PER_SECTION);
+	vmemmap_populate(map, PAGES_PER_SECTION, nid);
+#else
 	map = alloc_bootmem_node(NODE_DATA(nid),
 			sizeof(struct page) * PAGES_PER_SECTION);
+#endif
 	if (map)
 		return map;