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>

1 files changed, 9 insertions, 12 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e4af144ee409..9260314a221e 100644
--- 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;
 }