2 files changed, 54 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2e6635993558..6a29ed8e6e60 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -218,6 +218,11 @@ EXPORT_SYMBOL(nr_online_nodes);
 
 int page_group_by_mobility_disabled __read_mostly;
 
+/*
+ * NOTE:
+ * Don't use set_pageblock_migratetype(page, MIGRATE_ISOLATE) directly.
+ * Instead, use {un}set_pageblock_isolate.
+ */
 void set_pageblock_migratetype(struct page *page, int migratetype)
 {
 
@@ -1619,6 +1624,20 @@ static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 	return true;
 }
 
+#ifdef CONFIG_MEMORY_ISOLATION
+static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
+{
+	if (unlikely(zone->nr_pageblock_isolate))
+		return zone->nr_pageblock_isolate * pageblock_nr_pages;
+	return 0;
+}
+#else
+static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
+{
+	return 0;
+}
+#endif
+
 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 		      int classzone_idx, int alloc_flags)
 {
@@ -1634,6 +1653,14 @@ bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
 	if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
 		free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
 
+	/*
+	 * If the zone has MIGRATE_ISOLATE type free pages, we should consider
+	 * it.  nr_zone_isolate_freepages is never accurate so kswapd might not
+	 * sleep although it could do so.  But this is more desirable for memory
+	 * hotplug than sleeping which can cause a livelock in the direct
+	 * reclaim path.
+	 */
+	free_pages -= nr_zone_isolate_freepages(z);
 	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
 								free_pages);
 }
@@ -4398,6 +4425,9 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 		lruvec_init(&zone->lruvec, zone);
 		zap_zone_vm_stats(zone);
 		zone->flags = 0;
+#ifdef CONFIG_MEMORY_ISOLATION
+		zone->nr_pageblock_isolate = 0;
+#endif
 		if (!size)
 			continue;
 
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index fb482cf438da..247d1f175739 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -8,6 +8,28 @@
 #include <linux/memory.h>
 #include "internal.h"
 
+/* called while holding zone->lock */
+static void set_pageblock_isolate(struct page *page)
+{
+	if (get_pageblock_migratetype(page) == MIGRATE_ISOLATE)
+		return;
+
+	set_pageblock_migratetype(page, MIGRATE_ISOLATE);
+	page_zone(page)->nr_pageblock_isolate++;
+}
+
+/* called while holding zone->lock */
+static void restore_pageblock_isolate(struct page *page, int migratetype)
+{
+	struct zone *zone = page_zone(page);
+	if (WARN_ON(get_pageblock_migratetype(page) != MIGRATE_ISOLATE))
+		return;
+
+	BUG_ON(zone->nr_pageblock_isolate <= 0);
+	set_pageblock_migratetype(page, migratetype);
+	zone->nr_pageblock_isolate--;
+}
+
 int set_migratetype_isolate(struct page *page)
 {
 	struct zone *zone;
@@ -54,7 +76,7 @@ int set_migratetype_isolate(struct page *page)
 
 out:
 	if (!ret) {
-		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
+		set_pageblock_isolate(page);
 		move_freepages_block(zone, page, MIGRATE_ISOLATE);
 	}
 
@@ -72,8 +94,8 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 	spin_lock_irqsave(&zone->lock, flags);
 	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
 		goto out;
-	set_pageblock_migratetype(page, migratetype);
 	move_freepages_block(zone, page, migratetype);
+	restore_pageblock_isolate(page, migratetype);
 out:
 	spin_unlock_irqrestore(&zone->lock, flags);
 }