Index: linux-2.6.11/mm/page_alloc.c
===================================================================
--- linux-2.6.11.orig/mm/page_alloc.c	2005-03-16 17:12:51.000000000 -0800
+++ linux-2.6.11/mm/page_alloc.c	2005-03-16 17:17:28.000000000 -0800
@@ -633,13 +633,33 @@ void fastcall free_cold_page(struct page
 	free_hot_cold_page(page, 1);
 }
 
-static inline void prep_zero_page(struct page *page, int order, int gfp_flags)
+void prep_zero_page(struct page *page, unsigned int order, unsigned int gfp_flags)
 {
 	int i;
+	unsigned long t1;
 
 	BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
+
+#ifdef CONFIG_CLEAR_PAGES
+	if (!PageHighMem(page) && order>4) {
+		unsigned long t;
+
+		t1=get_cycles();
+		clear_pages(page_address(page), order);
+		t = get_cycles() - t1;
+		add_page_state(clear_pages_cycles, t);
+		add_page_state(clear_pages_order, 1 << order);
+		inc_page_state(clear_pages_nr);
+		return;
+	}
+#endif
+
+	t1=get_cycles();
 	for(i = 0; i < (1 << order); i++)
 		clear_highpage(page + i);
+	add_page_state(clear_page_cycles, get_cycles() - t1);
+	add_page_state(clear_page_order, 1 << order);
+	inc_page_state(clear_page_nr);
 }
 
 /*
Index: linux-2.6.11/include/linux/page-flags.h
===================================================================
--- linux-2.6.11.orig/include/linux/page-flags.h	2005-03-16 17:12:51.000000000 -0800
+++ linux-2.6.11/include/linux/page-flags.h	2005-03-16 17:13:02.000000000 -0800
@@ -131,6 +131,13 @@ struct page_state {
 	unsigned long allocstall;	/* direct reclaim calls */
 
 	unsigned long pgrotated;	/* pages rotated to tail of the LRU */
+
+	unsigned long clear_page_nr;	/* Nr of clear_page request */
+	unsigned long clear_page_cycles; /* Cycles spent in clear_page */
+	unsigned long clear_page_order;	/* Sum of orders */
+	unsigned long clear_pages_nr;	/* Nr of clear_pages requests */
+	unsigned long clear_pages_cycles;	/* Nr of cycles in clear_pages */
+	unsigned long clear_pages_order;	/* Sum of orders */
 };
 
 extern void get_page_state(struct page_state *ret);
Index: linux-2.6.11/fs/proc/proc_misc.c
===================================================================
--- linux-2.6.11.orig/fs/proc/proc_misc.c	2005-03-16 17:12:50.000000000 -0800
+++ linux-2.6.11/fs/proc/proc_misc.c	2005-03-16 17:22:18.000000000 -0800
@@ -127,7 +127,7 @@ static int meminfo_read_proc(char *page,
 	unsigned long allowed;
 	struct vmalloc_info vmi;
 
-	get_page_state(&ps);
+	get_full_page_state(&ps);
 	get_zone_counts(&active, &inactive, &free);
 
 /*
@@ -168,7 +168,13 @@ static int meminfo_read_proc(char *page,
 		"PageTables:   %8lu kB\n"
 		"VmallocTotal: %8lu kB\n"
 		"VmallocUsed:  %8lu kB\n"
-		"VmallocChunk: %8lu kB\n",
+		"VmallocChunk: %8lu kB\n"
+		"ClearPage #   %8lu\n"
+		"ClearPage Pgs %8lu\n"
+		"ClearPage Cyc %8lu\n"
+		"ClearPages #  %8lu\n"
+		"ClearPages Pg %8lu\n"
+		"ClearPages Cy %8lu\n",
 		K(i.totalram),
 		K(i.freeram),
 		K(i.bufferram),
@@ -191,7 +197,13 @@ static int meminfo_read_proc(char *page,
 		K(ps.nr_page_table_pages),
 		(unsigned long)VMALLOC_TOTAL >> 10,
 		vmi.used >> 10,
-		vmi.largest_chunk >> 10
+		vmi.largest_chunk >> 10,
+		ps.clear_page_nr,
+		ps.clear_page_order,
+		ps.clear_page_cycles,
+		ps.clear_pages_nr,
+		ps.clear_pages_order,
+		ps.clear_pages_cycles
 		);
 
 		len += hugetlb_report_meminfo(page + len);