1 files changed, 38 insertions, 30 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 5cbdfd065ab4..47aa50d263c2 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1168,7 +1168,8 @@ static int unmap_and_move(new_page_t get_new_page,
 				   free_page_t put_new_page,
 				   unsigned long private, struct page *page,
 				   int force, enum migrate_mode mode,
-				   enum migrate_reason reason)
+				   enum migrate_reason reason,
+				   struct list_head *ret)
 {
 	int rc = MIGRATEPAGE_SUCCESS;
 	struct page *newpage = NULL;
@@ -1205,7 +1206,14 @@ out:
 		 * migrated will have kept its references and be restored.
 		 */
 		list_del(&page->lru);
+	}
 
+	/*
+	 * If migration is successful, releases reference grabbed during
+	 * isolation. Otherwise, restore the page to right list unless
+	 * we want to retry.
+	 */
+	if (rc == MIGRATEPAGE_SUCCESS) {
 		/*
 		 * Compaction can migrate also non-LRU pages which are
 		 * not accounted to NR_ISOLATED_*. They can be recognized
@@ -1214,35 +1222,16 @@ out:
 		if (likely(!__PageMovable(page)))
 			mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
 					page_is_file_lru(page), -thp_nr_pages(page));
-	}
 
-	/*
-	 * If migration is successful, releases reference grabbed during
-	 * isolation. Otherwise, restore the page to right list unless
-	 * we want to retry.
-	 */
-	if (rc == MIGRATEPAGE_SUCCESS) {
 		if (reason != MR_MEMORY_FAILURE)
 			/*
 			 * We release the page in page_handle_poison.
 			 */
 			put_page(page);
 	} else {
-		if (rc != -EAGAIN) {
-			if (likely(!__PageMovable(page))) {
-				putback_lru_page(page);
-				goto put_new;
-			}
+		if (rc != -EAGAIN)
+			list_add_tail(&page->lru, ret);
 
-			lock_page(page);
-			if (PageMovable(page))
-				putback_movable_page(page);
-			else
-				__ClearPageIsolated(page);
-			unlock_page(page);
-			put_page(page);
-		}
-put_new:
 		if (put_new_page)
 			put_new_page(newpage, private);
 		else
@@ -1273,7 +1262,8 @@ put_new:
 static int unmap_and_move_huge_page(new_page_t get_new_page,
 				free_page_t put_new_page, unsigned long private,
 				struct page *hpage, int force,
-				enum migrate_mode mode, int reason)
+				enum migrate_mode mode, int reason,
+				struct list_head *ret)
 {
 	int rc = -EAGAIN;
 	int page_was_mapped = 0;
@@ -1289,7 +1279,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 	 * kicking migration.
 	 */
 	if (!hugepage_migration_supported(page_hstate(hpage))) {
-		putback_active_hugepage(hpage);
+		list_move_tail(&hpage->lru, ret);
 		return -ENOSYS;
 	}
 
@@ -1374,8 +1364,10 @@ put_anon:
 out_unlock:
 	unlock_page(hpage);
 out:
-	if (rc != -EAGAIN)
+	if (rc == MIGRATEPAGE_SUCCESS)
 		putback_active_hugepage(hpage);
+	else if (rc != -EAGAIN && rc != MIGRATEPAGE_SUCCESS)
+		list_move_tail(&hpage->lru, ret);
 
 	/*
 	 * If migration was not successful and there's a freeing callback, use
@@ -1406,8 +1398,8 @@ out:
  *
  * The function returns after 10 attempts or if no pages are movable any more
  * because the list has become empty or no retryable pages exist any more.
- * The caller should call putback_movable_pages() to return pages to the LRU
- * or free list only if ret != 0.
+ * It is caller's responsibility to call putback_movable_pages() to return pages
+ * to the LRU or free list only if ret != 0.
  *
  * Returns the number of pages that were not migrated, or an error code.
  */
@@ -1428,6 +1420,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 	struct page *page2;
 	int swapwrite = current->flags & PF_SWAPWRITE;
 	int rc, nr_subpages;
+	LIST_HEAD(ret_pages);
 
 	if (!swapwrite)
 		current->flags |= PF_SWAPWRITE;
@@ -1450,12 +1443,21 @@ retry:
 			if (PageHuge(page))
 				rc = unmap_and_move_huge_page(get_new_page,
 						put_new_page, private, page,
-						pass > 2, mode, reason);
+						pass > 2, mode, reason,
+						&ret_pages);
 			else
 				rc = unmap_and_move(get_new_page, put_new_page,
 						private, page, pass > 2, mode,
-						reason);
-
+						reason, &ret_pages);
+			/*
+			 * The rules are:
+			 *	Success: non hugetlb page will be freed, hugetlb
+			 *		 page will be put back
+			 *	-EAGAIN: stay on the from list
+			 *	-ENOMEM: stay on the from list
+			 *	Other errno: put on ret_pages list then splice to
+			 *		     from list
+			 */
 			switch(rc) {
 			case -ENOMEM:
 				/*
@@ -1521,6 +1523,12 @@ retry:
 	nr_thp_failed += thp_retry;
 	rc = nr_failed;
 out:
+	/*
+	 * Put the permanent failure page back to migration list, they
+	 * will be put back to the right list by the caller.
+	 */
+	list_splice(&ret_pages, from);
+
 	count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded);
 	count_vm_events(PGMIGRATE_FAIL, nr_failed);
 	count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded);