1 files changed, 30 insertions, 14 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2bf0d43d646b..0b6a6d04300a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -735,6 +735,13 @@ static void __free_pages_ok(struct page *page, unsigned int order)
 	local_irq_restore(flags);
 }
 
+/*
+ * Read access to zone->managed_pages is safe because it's unsigned long,
+ * but we still need to serialize writers. Currently all callers of
+ * __free_pages_bootmem() except put_page_bootmem() should only be used
+ * at boot time. So for shorter boot time, we shift the burden to
+ * put_page_bootmem() to serialize writers.
+ */
 void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
 {
 	unsigned int nr_pages = 1 << order;
@@ -750,6 +757,7 @@ void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
 		set_page_count(p, 0);
 	}
 
+	page_zone(page)->managed_pages += 1 << order;
 	set_page_refcounted(page);
 	__free_pages(page, order);
 }
@@ -2984,6 +2992,7 @@ void show_free_areas(unsigned int filter)
 			" isolated(anon):%lukB"
 			" isolated(file):%lukB"
 			" present:%lukB"
+			" managed:%lukB"
 			" mlocked:%lukB"
 			" dirty:%lukB"
 			" writeback:%lukB"
@@ -3013,6 +3022,7 @@ void show_free_areas(unsigned int filter)
 			K(zone_page_state(zone, NR_ISOLATED_ANON)),
 			K(zone_page_state(zone, NR_ISOLATED_FILE)),
 			K(zone->present_pages),
+			K(zone->managed_pages),
 			K(zone_page_state(zone, NR_MLOCK)),
 			K(zone_page_state(zone, NR_FILE_DIRTY)),
 			K(zone_page_state(zone, NR_WRITEBACK)),
@@ -4502,48 +4512,54 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 
 	for (j = 0; j < MAX_NR_ZONES; j++) {
 		struct zone *zone = pgdat->node_zones + j;
-		unsigned long size, realsize, memmap_pages;
+		unsigned long size, realsize, freesize, memmap_pages;
 
 		size = zone_spanned_pages_in_node(nid, j, zones_size);
-		realsize = size - zone_absent_pages_in_node(nid, j,
+		realsize = freesize = size - zone_absent_pages_in_node(nid, j,
 								zholes_size);
 
 		/*
-		 * Adjust realsize so that it accounts for how much memory
+		 * Adjust freesize so that it accounts for how much memory
 		 * is used by this zone for memmap. This affects the watermark
 		 * and per-cpu initialisations
 		 */
 		memmap_pages =
 			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
-		if (realsize >= memmap_pages) {
-			realsize -= memmap_pages;
+		if (freesize >= memmap_pages) {
+			freesize -= memmap_pages;
 			if (memmap_pages)
 				printk(KERN_DEBUG
 				       "  %s zone: %lu pages used for memmap\n",
 				       zone_names[j], memmap_pages);
 		} else
 			printk(KERN_WARNING
-				"  %s zone: %lu pages exceeds realsize %lu\n",
-				zone_names[j], memmap_pages, realsize);
+				"  %s zone: %lu pages exceeds freesize %lu\n",
+				zone_names[j], memmap_pages, freesize);
 
 		/* Account for reserved pages */
-		if (j == 0 && realsize > dma_reserve) {
-			realsize -= dma_reserve;
+		if (j == 0 && freesize > dma_reserve) {
+			freesize -= dma_reserve;
 			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
 					zone_names[0], dma_reserve);
 		}
 
 		if (!is_highmem_idx(j))
-			nr_kernel_pages += realsize;
-		nr_all_pages += realsize;
+			nr_kernel_pages += freesize;
+		nr_all_pages += freesize;
 
 		zone->spanned_pages = size;
-		zone->present_pages = realsize;
+		zone->present_pages = freesize;
+		/*
+		 * Set an approximate value for lowmem here, it will be adjusted
+		 * when the bootmem allocator frees pages into the buddy system.
+		 * And all highmem pages will be managed by the buddy system.
+		 */
+		zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
 #ifdef CONFIG_NUMA
 		zone->node = nid;
-		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
+		zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
 						/ 100;
-		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
+		zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
 #endif
 		zone->name = zone_names[j];
 		spin_lock_init(&zone->lock);