Merge tag 'nfsd-4.11' of git://linux-nfs.org/~bfields/linux

[mirror_ubuntu-artful-kernel.git] / block / elevator.c

diff --git a/block/elevator.c b/block/elevator.c
index 699d10f71a2cac3f871bb6879f68f1fc5fafe714..ac1c9f481a9895525b98601cf96837fd5b4015b6 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -220,17 +220,24 @@ int elevator_init(struct request_queue *q, char *name)
        }
 
        if (!e) {
-               if (q->mq_ops && q->nr_hw_queues == 1)
-                       e = elevator_get(CONFIG_DEFAULT_SQ_IOSCHED, false);
-               else if (q->mq_ops)
-                       e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false);
-               else
+               /*
+                * For blk-mq devices, we default to using mq-deadline,
+                * if available, for single queue devices. If deadline
+                * isn't available OR we have multiple queues, default
+                * to "none".
+                */
+               if (q->mq_ops) {
+                       if (q->nr_hw_queues == 1)
+                               e = elevator_get("mq-deadline", false);
+                       if (!e)
+                               return 0;
+               } else
                        e = elevator_get(CONFIG_DEFAULT_IOSCHED, false);
 
                if (!e) {
                        printk(KERN_ERR
                                "Default I/O scheduler not found. " \
-                               "Using noop/none.\n");
+                               "Using noop.\n");
                        e = elevator_get("noop", false);
                }
        }