mm: numa: avoid unnecessary work on the failure path

If a PMD changes during a THP migration then migration aborts but the
failure path is doing more work than is necessary.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/migrate.c b/mm/migrate.c
index be787d5..a987525 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1780,7 +1780,8 @@ fail_putback:
                putback_lru_page(page);
                mod_zone_page_state(page_zone(page),
                         NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR);
-               goto out_fail;
+
+               goto out_unlock;
        }
 
        /*
@@ -1854,6 +1855,7 @@ out_dropref:
        }
        spin_unlock(ptl);
 
+out_unlock:
        unlock_page(page);
        put_page(page);
        return 0;