blk-mq: user (1 << order) to implement order_to_size()

Cc: Jörg-Volker Peetz <jvpeetz@web.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 1 insertions, 6 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index c2777970f28b..3a560a4db0b4 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1130,12 +1130,7 @@ static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
 
 static size_t order_to_size(unsigned int order)
 {
-        size_t ret = PAGE_SIZE;
-
-        while (order--)
-                ret *= 2;
-
-        return ret;
+        return (size_t)PAGE_SIZE << order;
 }
 
 static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,