diff -urNp x-ref/mm/page_alloc.c x/mm/page_alloc.c
--- x-ref/mm/page_alloc.c	2003-02-14 18:40:18.000000000 +0100
+++ x/mm/page_alloc.c	2003-02-14 18:41:00.000000000 +0100
@@ -649,6 +649,41 @@ unsigned int nr_free_highpages (void)
 }
 #endif
 
+/*
+ * If it returns non zero it means there's lots of ram "free"
+ * (note: not in cache!) so any caller will know that
+ * he can allocate some memory to do some more aggressive
+ * (possibly wasteful) readahead. The state of the memory
+ * should be rechecked after every few pages allocated for
+ * doing this aggressive readahead.
+ *
+ * The gfp_mask parameter specifies in which kind of memory
+ * the readahead information will be applicated to.
+ */
+int start_aggressive_readahead(unsigned int gfp_mask)
+{
+	pg_data_t *pgdat = pgdat_list;
+	zonelist_t *zonelist;
+	zone_t **zonep, *zone;
+	int ret = 0;
+
+	do {
+		int class_idx;
+		zonelist = pgdat->node_zonelists + (gfp_mask & GFP_ZONEMASK);
+		zonep = zonelist->zones;
+		zone = *(zonep++);
+		class_idx = zone_idx(zone);
+
+		for (; zone; zone = *(zonep++))
+			if (zone->free_pages > zone->watermarks[class_idx].high * 2)
+				ret = 1;
+
+		pgdat = pgdat->node_next;
+	} while (pgdat);
+
+	return ret;
+}
+
 #define K(x) ((x) << (PAGE_SHIFT-10))
 
 /*