crush: do is_out test only if we do not collide

The is_out() test may require an additional hashing operation, so we
should skip it whenever possible.

Reflects ceph.git commit db107cc7f15cf2481894add325dc93e33479f529.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/net/ceph/crush/mapper.c b/net/ceph/crush/mapper.c
index 2e31217ccae3b52f1ec3162cb08c25fcf59cbc13..84d2de04786530a3765564842a2a0cbef8a02a9a 100644 (file)
--- a/net/ceph/crush/mapper.c
+++ b/net/ceph/crush/mapper.c
@@ -552,14 +552,12 @@ static int crush_choose_firstn(const struct crush_map *map,
                                        }
                                }
 
-                               if (!reject) {
+                               if (!reject && !collide) {
                                        /* out? */
                                        if (itemtype == 0)
                                                reject = is_out(map, weight,
                                                                weight_max,
                                                                item, x);
-                                       else
-                                               reject = 0;
                                }
 
 reject: