1 files changed, 42 insertions, 37 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d4e940a26945..2c6523af5473 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -34,6 +34,23 @@
 
 #include "internal.h"
 
+DEFINE_MUTEX(mem_hotplug_mutex);
+
+void lock_memory_hotplug(void)
+{
+	mutex_lock(&mem_hotplug_mutex);
+
+	/* for exclusive hibernation if CONFIG_HIBERNATION=y */
+	lock_system_sleep();
+}
+
+void unlock_memory_hotplug(void)
+{
+	unlock_system_sleep();
+	mutex_unlock(&mem_hotplug_mutex);
+}
+
+
 /* add this memory to iomem resource */
 static struct resource *register_memory_resource(u64 start, u64 size)
 {
@@ -493,7 +510,7 @@ int mem_online_node(int nid)
 	pg_data_t	*pgdat;
 	int	ret;
 
-	lock_system_sleep();
+	lock_memory_hotplug();
 	pgdat = hotadd_new_pgdat(nid, 0);
 	if (pgdat) {
 		ret = -ENOMEM;
@@ -504,7 +521,7 @@ int mem_online_node(int nid)
 	BUG_ON(ret);
 
 out:
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return ret;
 }
 
@@ -516,7 +533,7 @@ int __ref add_memory(int nid, u64 start, u64 size)
 	struct resource *res;
 	int ret;
 
-	lock_system_sleep();
+	lock_memory_hotplug();
 
 	res = register_memory_resource(start, size);
 	ret = -EEXIST;
@@ -563,7 +580,7 @@ error:
 		release_memory_resource(res);
 
 out:
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(add_memory);
@@ -602,27 +619,14 @@ static struct page *next_active_pageblock(struct page *page)
 /* Checks if this range of memory is likely to be hot-removable. */
 int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
 {
-	int type;
 	struct page *page = pfn_to_page(start_pfn);
 	struct page *end_page = page + nr_pages;
 
 	/* Check the starting page of each pageblock within the range */
 	for (; page < end_page; page = next_active_pageblock(page)) {
-		type = get_pageblock_migratetype(page);
-
-		/*
-		 * A pageblock containing MOVABLE or free pages is considered
-		 * removable
-		 */
-		if (type != MIGRATE_MOVABLE && !pageblock_free(page))
-			return 0;
-
-		/*
-		 * A pageblock starting with a PageReserved page is not
-		 * considered removable.
-		 */
-		if (PageReserved(page))
+		if (!is_pageblock_removable_nolock(page))
 			return 0;
+		cond_resched();
 	}
 
 	/* All pageblocks in the memory block are likely to be hot-removable */
@@ -659,7 +663,7 @@ static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
  * Scanning pfn is much easier than scanning lru list.
  * Scan pfn from start to end and Find LRU page.
  */
-int scan_lru_pages(unsigned long start, unsigned long end)
+static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
 {
 	unsigned long pfn;
 	struct page *page;
@@ -709,29 +713,30 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 					    page_is_file_cache(page));
 
 		} else {
-			/* Becasue we don't have big zone->lock. we should
-			   check this again here. */
-			if (page_count(page))
-				not_managed++;
 #ifdef CONFIG_DEBUG_VM
 			printk(KERN_ALERT "removing pfn %lx from LRU failed\n",
 			       pfn);
 			dump_page(page);
 #endif
+			/* Becasue we don't have big zone->lock. we should
+			   check this again here. */
+			if (page_count(page)) {
+				not_managed++;
+				ret = -EBUSY;
+				break;
+			}
 		}
 	}
-	ret = -EBUSY;
-	if (not_managed) {
-		if (!list_empty(&source))
+	if (!list_empty(&source)) {
+		if (not_managed) {
+			putback_lru_pages(&source);
+			goto out;
+		}
+		/* this function returns # of failed pages */
+		ret = migrate_pages(&source, hotremove_migrate_alloc, 0, 1);
+		if (ret)
 			putback_lru_pages(&source);
-		goto out;
 	}
-	ret = 0;
-	if (list_empty(&source))
-		goto out;
-	/* this function returns # of failed pages */
-	ret = migrate_pages(&source, hotremove_migrate_alloc, 0, 1);
-
 out:
 	return ret;
 }
@@ -803,7 +808,7 @@ static int offline_pages(unsigned long start_pfn,
 	if (!test_pages_in_a_zone(start_pfn, end_pfn))
 		return -EINVAL;
 
-	lock_system_sleep();
+	lock_memory_hotplug();
 
 	zone = page_zone(pfn_to_page(start_pfn));
 	node = zone_to_nid(zone);
@@ -892,7 +897,7 @@ repeat:
 	writeback_set_ratelimit();
 
 	memory_notify(MEM_OFFLINE, &arg);
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return 0;
 
 failed_removal:
@@ -903,7 +908,7 @@ failed_removal:
 	undo_isolate_page_range(start_pfn, end_pfn);
 
 out:
-	unlock_system_sleep();
+	unlock_memory_hotplug();
 	return ret;
 }