Cleanup per cpu pages a bit

- Replace ARRAY_SIZE(xxx->pcp) with NR_PER_CPU_PAGES

- Use string array for temperature descriptions.

- Index pcp arrays with PER_CPU_HOT and PER_CPU_COLD

- Use common index i to index pcps in show_free_areas

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.16-rc1-mm3/mm/page_alloc.c
===================================================================
--- linux-2.6.16-rc1-mm3.orig/mm/page_alloc.c	2006-01-25 10:02:09.000000000 -0800
+++ linux-2.6.16-rc1-mm3/mm/page_alloc.c	2006-01-26 10:19:32.000000000 -0800
@@ -610,7 +610,7 @@ void drain_remote_pages(void)
 			continue;
 
 		pset = zone_pcp(zone, smp_processor_id());
-		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
+		for (i = 0; i < NR_PER_CPU_PAGES; i++) {
 			struct per_cpu_pages *pcp;
 
 			pcp = &pset->pcp[i];
@@ -633,7 +633,7 @@ static void __drain_pages(unsigned int c
 		struct per_cpu_pageset *pset;
 
 		pset = zone_pcp(zone, cpu);
-		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
+		for (i = 0; i < NR_PER_CPU_PAGES; i++) {
 			struct per_cpu_pages *pcp;
 
 			pcp = &pset->pcp[i];
@@ -1452,6 +1452,8 @@ void si_meminfo_node(struct sysinfo *val
 
 #define K(x) ((x) << (PAGE_SHIFT-10))
 
+static const char *temperature_descr[] = { "cold", "hot" };
+
 /*
  * Show free area list (used inside shift_scroll-lock stuff)
  * We also calculate the percentage fragmentation. We do this by counting the
@@ -1460,7 +1462,7 @@ void si_meminfo_node(struct sysinfo *val
 void show_free_areas(void)
 {
 	struct page_state ps;
-	int cpu, temperature;
+	int cpu;
 	unsigned long active;
 	unsigned long inactive;
 	unsigned long free;
@@ -1478,16 +1480,17 @@ void show_free_areas(void)
 
 		for_each_online_cpu(cpu) {
 			struct per_cpu_pageset *pageset;
+			int i;
 
 			pageset = zone_pcp(zone, cpu);
 
-			for (temperature = 0; temperature < 2; temperature++)
+			for (i = 0; i < NR_PER_CPU_PAGES; i++)
 				printk("cpu %d %s: high %d, batch %d used:%d\n",
 					cpu,
-					temperature ? "cold" : "hot",
-					pageset->pcp[temperature].high,
-					pageset->pcp[temperature].batch,
-					pageset->pcp[temperature].count);
+					temperature_descr[i],
+					pageset->pcp[i].high,
+					pageset->pcp[i].batch,
+					pageset->pcp[i].count);
 		}
 	}
 
@@ -1929,13 +1932,13 @@ inline void setup_pageset(struct per_cpu
 
 	memset(p, 0, sizeof(*p));
 
-	pcp = &p->pcp[0];		/* hot */
+	pcp = &p->pcp[PER_CPU_HOT];
 	pcp->count = 0;
 	pcp->high = 6 * batch;
 	pcp->batch = max(1UL, 1 * batch);
 	INIT_LIST_HEAD(&pcp->list);
 
-	pcp = &p->pcp[1];		/* cold*/
+	pcp = &p->pcp[PER_CPU_COLD];
 	pcp->count = 0;
 	pcp->high = 2 * batch;
 	pcp->batch = max(1UL, batch/2);
@@ -2342,13 +2345,13 @@ static int zoneinfo_show(struct seq_file
 			int j;
 
 			pageset = zone_pcp(zone, i);
-			for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
+			for (j = 0; j < NR_PER_CPU_PAGES; j++) {
 				if (pageset->pcp[j].count)
 					break;
 			}
-			if (j == ARRAY_SIZE(pageset->pcp))
+			if (j == NR_PER_CPU_PAGES)
 				continue;
-			for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
+			for (j = 0; j < NR_PER_CPU_PAGES; j++) {
 				seq_printf(m,
 					   "\n    cpu: %i pcp: %i"
 					   "\n              count: %i"
Index: linux-2.6.16-rc1-mm3/include/linux/mmzone.h
===================================================================
--- linux-2.6.16-rc1-mm3.orig/include/linux/mmzone.h	2006-01-25 10:02:09.000000000 -0800
+++ linux-2.6.16-rc1-mm3/include/linux/mmzone.h	2006-01-26 10:14:35.000000000 -0800
@@ -22,6 +22,12 @@
 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
 #endif
 
+#define NR_PER_CPU_PAGES 2
+
+/* Types of per cpu pages */
+#define PER_CPU_HOT 0
+#define PER_CPU_COLD 1
+
 struct free_area {
 	struct list_head	free_list;
 	unsigned long		nr_free;
@@ -52,7 +58,7 @@ struct per_cpu_pages {
 };
 
 struct per_cpu_pageset {
-	struct per_cpu_pages pcp[2];	/* 0: hot.  1: cold */
+	struct per_cpu_pages pcp[NR_PER_CPU_PAGES];
 #ifdef CONFIG_NUMA
 	unsigned long numa_hit;		/* allocated in intended node */
 	unsigned long numa_miss;	/* allocated in non intended node */