block: Schedule runtime resume earlier

Instead of scheduling runtime resume of a request queue after a
request has been queued, schedule asynchronous resume during request
allocation. The new pm_request_resume() calls occur after
blk_queue_enter() has increased the q_usage_counter request queue
member. This change is needed for a later patch that will make request
allocation block while the queue status is not RPM_ACTIVE.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-core.c b/block/blk-core.c
index fd91e9b..fec135a 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -956,7 +956,8 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 
                wait_event(q->mq_freeze_wq,
                           (atomic_read(&q->mq_freeze_depth) == 0 &&
-                           (pm || !blk_queue_pm_only(q))) ||
+                           (pm || (blk_pm_request_resume(q),
+                                   !blk_queue_pm_only(q)))) ||
                           blk_queue_dying(q));
                if (blk_queue_dying(q))
                        return -ENODEV;

diff --git a/block/elevator.c b/block/elevator.c
index 1c992bf..e18ac68 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -601,7 +601,6 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
        trace_block_rq_insert(q, rq);
 
        blk_pm_add_request(q, rq);
-       blk_pm_request_resume(q);
 
        rq->q = q;