patch-2.4.20 linux-2.4.20/include/linux/mmzone.h

• Lines: 71
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/linux/mmzone.h
• Orig date: Fri Aug 2 17:39:45 2002

diff -urN linux-2.4.19/include/linux/mmzone.h linux-2.4.20/include/linux/mmzone.h
@@ -158,6 +158,60 @@
 
 extern pg_data_t contig_page_data;
 
+/**
+ * for_each_pgdat - helper macro to iterate over all nodes
+ * @pgdat - pg_data_t * variable
+ *
+ * Meant to help with common loops of the form
+ * pgdat = pgdat_list;
+ * while(pgdat) {
+ * 	...
+ * 	pgdat = pgdat->node_next;
+ * }
+ */
+#define for_each_pgdat(pgdat) \
+	for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next)
+
+
+/*
+ * next_zone - helper magic for for_each_zone()
+ * Thanks to William Lee Irwin III for this piece of ingenuity.
+ */
+static inline zone_t *next_zone(zone_t *zone)
+{
+	pg_data_t *pgdat = zone->zone_pgdat;
+
+	if (zone - pgdat->node_zones < MAX_NR_ZONES - 1)
+		zone++;
+
+	else if (pgdat->node_next) {
+		pgdat = pgdat->node_next;
+		zone = pgdat->node_zones;
+	} else
+		zone = NULL;
+
+	return zone;
+}
+
+/**
+ * for_each_zone - helper macro to iterate over all memory zones
+ * @zone - zone_t * variable
+ *
+ * The user only needs to declare the zone variable, for_each_zone
+ * fills it in. This basically means for_each_zone() is an
+ * easier to read version of this piece of code:
+ *
+ * for(pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next)
+ * 	for(i = 0; i < MAX_NR_ZONES; ++i) {
+ * 		zone_t * z = pgdat->node_zones + i;
+ * 		...
+ * 	}
+ * }
+ */
+#define for_each_zone(zone) \
+	for(zone = pgdat_list->node_zones; zone; zone = next_zone(zone))
+
+
 #ifndef CONFIG_DISCONTIGMEM
 
 #define NODE_DATA(nid)		(&contig_page_data)
@@ -169,7 +223,9 @@
 #include <asm/mmzone.h>
 
 /* page->zone is currently 8 bits ... */
+#ifndef MAX_NR_NODES
 #define MAX_NR_NODES		(255 / MAX_NR_ZONES)
+#endif
 
 #endif /* !CONFIG_DISCONTIGMEM */