mm/compaction.c: fix "suitable_migration_target() unused" warning

mm/compaction.c:250:13: warning: 'suitable_migration_target' defined but not used [-Wunused-function]

Reported-by: Fengguang Wu <fengguang.wu@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 22 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index e6c4f9475d43..018f08da99a2 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -391,28 +391,6 @@ static inline bool compact_should_abort(struct compact_control *cc)
         return false;
 }
 
-/* Returns true if the page is within a block suitable for migration to */
-static bool suitable_migration_target(struct page *page)
-{
-        /* If the page is a large free page, then disallow migration */
-        if (PageBuddy(page)) {
-                /*
-                 * We are checking page_order without zone->lock taken. But
-                 * the only small danger is that we skip a potentially suitable
-                 * pageblock, so it's not worth to check order for valid range.
-                 */
-                if (page_order_unsafe(page) >= pageblock_order)
-                        return false;
-        }
-
-        /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
-        if (migrate_async_suitable(get_pageblock_migratetype(page)))
-                return true;
-
-        /* Otherwise skip the block */
-        return false;
-}
-
 /*
  * Isolate free pages onto a private freelist. If @strict is true, will abort
  * returning 0 on any invalid PFNs or non-free pages inside of the pageblock
@@ -896,6 +874,29 @@ isolate_migratepages_range(struct compact_control *cc, unsigned long start_pfn,
 
 #endif /* CONFIG_COMPACTION || CONFIG_CMA */
 #ifdef CONFIG_COMPACTION
+
+/* Returns true if the page is within a block suitable for migration to */
+static bool suitable_migration_target(struct page *page)
+{
+        /* If the page is a large free page, then disallow migration */
+        if (PageBuddy(page)) {
+                /*
+                 * We are checking page_order without zone->lock taken. But
+                 * the only small danger is that we skip a potentially suitable
+                 * pageblock, so it's not worth to check order for valid range.
+                 */
+                if (page_order_unsafe(page) >= pageblock_order)
+                        return false;
+        }
+
+        /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
+        if (migrate_async_suitable(get_pageblock_migratetype(page)))
+                return true;
+
+        /* Otherwise skip the block */
+        return false;
+}
+
 /*
  * Based on information in the current compact_control, find blocks
  * suitable for isolating free pages from and then isolate them.