Merge 3.8-rc5 into tty-next

This resolves a number of tty driver merge issues found in linux-next

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 1 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 3b676b0c5c3e..c38778610aa8 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1679,9 +1679,21 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
         page_xchg_last_nid(new_page, page_last_nid(page));
 
         isolated = numamigrate_isolate_page(pgdat, page);
-        if (!isolated) {
+
+        /*
+         * Failing to isolate or a GUP pin prevents migration. The expected
+         * page count is 2. 1 for anonymous pages without a mapping and 1
+         * for the callers pin. If the page was isolated, the page will
+         * need to be put back on the LRU.
+         */
+        if (!isolated || page_count(page) != 2) {
                 count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR);
                 put_page(new_page);
+                if (isolated) {
+                        putback_lru_page(page);
+                        isolated = 0;
+                        goto out;
+                }
                 goto out_keep_locked;
         }