[PATCH] mm: cleanup zone_pcp

Use zone_pcp everywhere even though NUMA code "knows" the internal details
of the zone.  Stop other people trying to copy, and it looks nicer.

Also, only print the pagesets of online cpus in zoneinfo.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/page_alloc.c

@@ -597,7 +597,7 @@ void drain_remote_pages(void)
 		if (zone->zone_pgdat->node_id == numa_node_id())
 			continue;
 
-		pset = zone->pageset[smp_processor_id()];
+		pset = zone_pcp(zone, smp_processor_id());
 		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
 			struct per_cpu_pages *pcp;
 
@@ -1881,12 +1881,12 @@ static int __devinit process_zones(int cpu)
 
 	for_each_zone(zone) {
 
-		zone->pageset[cpu] = kmalloc_node(sizeof(struct per_cpu_pageset),
+		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
 					 GFP_KERNEL, cpu_to_node(cpu));
-		if (!zone->pageset[cpu])
+		if (!zone_pcp(zone, cpu))
 			goto bad;
 
-		setup_pageset(zone->pageset[cpu], zone_batchsize(zone));
+		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
 
 		if (percpu_pagelist_fraction)
 			setup_pagelist_highmark(zone_pcp(zone, cpu),
@@ -1898,8 +1898,8 @@ bad:
 	for_each_zone(dzone) {
 		if (dzone == zone)
 			break;
-		kfree(dzone->pageset[cpu]);
-		dzone->pageset[cpu] = NULL;
+		kfree(zone_pcp(dzone, cpu));
+		zone_pcp(dzone, cpu) = NULL;
 	}
 	return -ENOMEM;
 }
@@ -1984,7 +1984,7 @@ static __devinit void zone_pcp_init(struct zone *zone)
 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
 #ifdef CONFIG_NUMA
 		/* Early boot. Slab allocator not functional yet */
-		zone->pageset[cpu] = &boot_pageset[cpu];
+		zone_pcp(zone, cpu) = &boot_pageset[cpu];
 		setup_pageset(&boot_pageset[cpu],0);
 #else
 		setup_pageset(zone_pcp(zone,cpu), batch);
@@ -2227,7 +2227,7 @@ static int zoneinfo_show(struct seq_file *m, void *arg)
 		seq_printf(m,
 			   ")"
 			   "\n  pagesets");
-		for (i = 0; i < ARRAY_SIZE(zone->pageset); i++) {
+		for_each_online_cpu(i) {
 			struct per_cpu_pageset *pageset;
 			int j;