mm/migration: avoid unneeded nodemask_t initialization

Avoid unneeded next_pass and this_pass initialization as they're always
set before using to save possible cpu cycles when there are plenty of
nodes in the system.

Link: https://lkml.kernel.org/r/20220318111709.60311-8-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/migrate.c b/mm/migrate.c
index 02448b6..d9f378b 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2345,8 +2345,8 @@ out_clear:
  */
 static void __set_migration_target_nodes(void)
 {
-       nodemask_t next_pass    = NODE_MASK_NONE;
-       nodemask_t this_pass    = NODE_MASK_NONE;
+       nodemask_t next_pass;
+       nodemask_t this_pass;
        nodemask_t used_targets = NODE_MASK_NONE;
        int node, best_distance;