1 files changed, 34 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8ac593893e6e..00750bc08a3a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6087,3 +6087,37 @@ void dump_page(struct page *page)
 	dump_page_flags(page->flags);
 	mem_cgroup_print_bad_page(page);
 }
+
+/* reset zone->present_pages */
+void reset_zone_present_pages(void)
+{
+	struct zone *z;
+	int i, nid;
+
+	for_each_node_state(nid, N_HIGH_MEMORY) {
+		for (i = 0; i < MAX_NR_ZONES; i++) {
+			z = NODE_DATA(nid)->node_zones + i;
+			z->present_pages = 0;
+		}
+	}
+}
+
+/* calculate zone's present pages in buddy system */
+void fixup_zone_present_pages(int nid, unsigned long start_pfn,
+				unsigned long end_pfn)
+{
+	struct zone *z;
+	unsigned long zone_start_pfn, zone_end_pfn;
+	int i;
+
+	for (i = 0; i < MAX_NR_ZONES; i++) {
+		z = NODE_DATA(nid)->node_zones + i;
+		zone_start_pfn = z->zone_start_pfn;
+		zone_end_pfn = zone_start_pfn + z->spanned_pages;
+
+		/* if the two regions intersect */
+		if (!(zone_start_pfn >= end_pfn	|| zone_end_pfn <= start_pfn))
+			z->present_pages += min(end_pfn, zone_end_pfn) -
+					    max(start_pfn, zone_start_pfn);
+	}
+}