mm: do_migrate_range: reduce list_empty() check

Simple code for reducing list_empty(&source) check.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e4af144..9260314 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -705,24 +705,21 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
                           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);
-       if (ret)
-               putback_lru_pages(&source);
-
 out:
        return ret;
 }