[PATCH] Use ZVC for free_pages

This is again simplifies some of the VM counter calculations through the use
of the ZVC consolidated counters.

[michal.k.k.piotrowski@gmail.com: build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 24 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 07c954e..ba62d87 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -395,7 +395,7 @@ static inline void __free_one_page(struct page *page,
 	VM_BUG_ON(page_idx & (order_size - 1));
 	VM_BUG_ON(bad_range(zone, page));
 
-	zone->free_pages += order_size;
+	__mod_zone_page_state(zone, NR_FREE_PAGES, order_size);
 	while (order < MAX_ORDER-1) {
 		unsigned long combined_idx;
 		struct free_area *area;
@@ -631,7 +631,7 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order)
 		list_del(&page->lru);
 		rmv_page_order(page);
 		area->nr_free--;
-		zone->free_pages -= 1UL << order;
+		__mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order));
 		expand(zone, page, order, current_order, area);
 		return page;
 	}
@@ -989,7 +989,8 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 		      int classzone_idx, int alloc_flags)
 {
 	/* free_pages my go negative - that's OK */
-	long min = mark, free_pages = z->free_pages - (1 << order) + 1;
+	long min = mark;
+	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
 	int o;
 
 	if (alloc_flags & ALLOC_HIGH)
@@ -1444,13 +1445,7 @@ EXPORT_SYMBOL(free_pages);
  */
 unsigned int nr_free_pages(void)
 {
-	unsigned int sum = 0;
-	struct zone *zone;
-
-	for_each_zone(zone)
-		sum += zone->free_pages;
-
-	return sum;
+	return global_page_state(NR_FREE_PAGES);
 }
 
 EXPORT_SYMBOL(nr_free_pages);
@@ -1458,13 +1453,7 @@ EXPORT_SYMBOL(nr_free_pages);
 #ifdef CONFIG_NUMA
 unsigned int nr_free_pages_pgdat(pg_data_t *pgdat)
 {
-	unsigned int sum = 0;
-	enum zone_type i;
-
-	for (i = 0; i < MAX_NR_ZONES; i++)
-		sum += pgdat->node_zones[i].free_pages;
-
-	return sum;
+	return node_page_state(pgdat->node_id, NR_FREE_PAGES);
 }
 #endif
 
@@ -1514,7 +1503,7 @@ void si_meminfo(struct sysinfo *val)
 {
 	val->totalram = totalram_pages;
 	val->sharedram = 0;
-	val->freeram = nr_free_pages();
+	val->freeram = global_page_state(NR_FREE_PAGES);
 	val->bufferram = nr_blockdev_pages();
 	val->totalhigh = totalhigh_pages;
 	val->freehigh = nr_free_highpages();
@@ -1529,10 +1518,11 @@ void si_meminfo_node(struct sysinfo *val, int nid)
 	pg_data_t *pgdat = NODE_DATA(nid);
 
 	val->totalram = pgdat->node_present_pages;
-	val->freeram = nr_free_pages_pgdat(pgdat);
+	val->freeram = node_page_state(nid, NR_FREE_PAGES);
 #ifdef CONFIG_HIGHMEM
 	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
-	val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages;
+	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
+			NR_FREE_PAGES);
 #else
 	val->totalhigh = 0;
 	val->freehigh = 0;
@@ -1580,13 +1570,13 @@ void show_free_areas(void)
 	get_zone_counts(&active, &inactive, &free);
 
 	printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
-		" free:%u slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
+		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
 		active,
 		inactive,
 		global_page_state(NR_FILE_DIRTY),
 		global_page_state(NR_WRITEBACK),
 		global_page_state(NR_UNSTABLE_NFS),
-		nr_free_pages(),
+		global_page_state(NR_FREE_PAGES),
 		global_page_state(NR_SLAB_RECLAIMABLE) +
 			global_page_state(NR_SLAB_UNRECLAIMABLE),
 		global_page_state(NR_FILE_MAPPED),
@@ -1612,7 +1602,7 @@ void show_free_areas(void)
 			" all_unreclaimable? %s"
 			"\n",
 			zone->name,
-			K(zone->free_pages),
+			K(zone_page_state(zone, NR_FREE_PAGES)),
 			K(zone->pages_min),
 			K(zone->pages_low),
 			K(zone->pages_high),
@@ -2675,7 +2665,6 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
 		spin_lock_init(&zone->lru_lock);
 		zone_seqlock_init(zone);
 		zone->zone_pgdat = pgdat;
-		zone->free_pages = 0;
 
 		zone->prev_priority = DEF_PRIORITY;