- /*
- * SCSI probing may synchronously create and destroy a lot of
- * request_queues for non-existent devices. Shutting down a fully
- * functional queue takes measureable wallclock time as RCU grace
- * periods are involved. To avoid excessive latency in these
- * cases, a request_queue starts out in a degraded mode which is
- * faster to shut down and is made fully functional here as
- * request_queues for non-existent devices never get registered.
- */
- if (!blk_queue_init_done(q)) {
- blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
- percpu_ref_switch_to_percpu(&q->q_usage_counter);
- }
-