oom: change all_unreclaimable zone member to flags

Convert the int all_unreclaimable member of struct zone to unsigned long
flags.  This can now be used to specify several different zone flags such as
all_unreclaimable and reclaim_in_progress, which can now be removed and
converted to a per-zone flag.

Flags are set and cleared as follows:

	zone_set_flag(struct zone *zone, zone_flags_t flag)
	zone_clear_flag(struct zone *zone, zone_flags_t flag)

Defines the first zone flags, ZONE_ALL_UNRECLAIMABLE and ZONE_RECLAIM_LOCKED,
which have the same semantics as the old zone->all_unreclaimable and
zone->reclaim_in_progress, respectively.  Also converts all current users that
set or clear either flag to use the new interface.

Helper functions are defined to test the flags:

	int zone_is_all_unreclaimable(const struct zone *zone)
	int zone_is_reclaim_locked(const struct zone *zone)

All flag operators are of the atomic variety because there are currently
readers that are implemented that do not take zone->lock.

[akpm@linux-foundation.org: add needed include]
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0e3a05fd4734..fd2df29cc645 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -490,7 +490,7 @@ static void free_pages_bulk(struct zone *zone, int count,
 					struct list_head *list, int order)
 {
 	spin_lock(&zone->lock);
-	zone->all_unreclaimable = 0;
+	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
 	zone->pages_scanned = 0;
 	while (count--) {
 		struct page *page;
@@ -507,7 +507,7 @@ static void free_pages_bulk(struct zone *zone, int count,
 static void free_one_page(struct zone *zone, struct page *page, int order)
 {
 	spin_lock(&zone->lock);
-	zone->all_unreclaimable = 0;
+	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
 	zone->pages_scanned = 0;
 	__free_one_page(page, zone, order);
 	spin_unlock(&zone->lock);
@@ -1851,7 +1851,7 @@ void show_free_areas(void)
 			K(zone_page_state(zone, NR_INACTIVE)),
 			K(zone->present_pages),
 			zone->pages_scanned,
-			(zone->all_unreclaimable ? "yes" : "no")
+			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
 			);
 		printk("lowmem_reserve[]:");
 		for (i = 0; i < MAX_NR_ZONES; i++)
@@ -3372,7 +3372,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
 		zone->nr_scan_active = 0;
 		zone->nr_scan_inactive = 0;
 		zap_zone_vm_stats(zone);
-		atomic_set(&zone->reclaim_in_progress, 0);
+		zone->flags = 0;
 		if (!size)
 			continue;