Oracle bug 8300888
The balloon code needs to adjust totalhigh_pages
5/8/2009 Chuck Anderson

The balloon code needs to adjust the global kernel symbol totalhigh_pages 
when it adds/removes pages from/to high memory.  Otherwise, totalhigh_pages
will not represent the number of pages in high memory.
--- linux-2.6.9/mm/page_alloc.c.orig	2009-03-10 14:30:29.000000000 -0700
+++ linux-2.6.9/mm/page_alloc.c	2009-03-10 14:32:47.000000000 -0700
@@ -44,6 +44,7 @@
 int sysctl_lower_zone_protection = 0;
 
 EXPORT_SYMBOL(totalram_pages);
+EXPORT_SYMBOL(totalhigh_pages);
 EXPORT_SYMBOL(nr_swap_pages);
 
 /*
--- linux-2.6.9/drivers/xen/balloon/balloon.c.orig	2009-03-10 14:33:36.000000000 -0700
+++ linux-2.6.9/drivers/xen/balloon/balloon.c	2009-03-10 14:38:37.000000000 -0700
@@ -92,6 +92,7 @@
 
 /* VM /proc information for memory */
 extern unsigned long totalram_pages;
+extern unsigned long totalhigh_pages;
 
 /* We may hit the hard limit in Xen. If we do then we remember it. */
 static unsigned long hard_limit;
@@ -137,6 +138,7 @@
 	if (PageHighMem(page)) {
 		list_add_tail(PAGE_TO_LIST(page), &ballooned_pages);
 		balloon_high++;
+		totalhigh_pages--;
 	} else {
 		list_add(PAGE_TO_LIST(page), &ballooned_pages);
 		balloon_low++;
@@ -154,10 +156,13 @@
 	page = LIST_TO_PAGE(ballooned_pages.next);
 	UNLIST_PAGE(page);
 
-	if (PageHighMem(page))
+	if (PageHighMem(page)) {
 		balloon_high--;
-	else
+		totalhigh_pages++;
+	}
+	else {
 		balloon_low--;
+	}
 
 	return page;
 }
@@ -609,6 +614,9 @@
 		}
 
 		totalram_pages = --current_pages;
+		if (PageHighMem(page)) {
+			totalhigh_pages--;
+		}
 
 		balloon_unlock(flags);
 	}