blk-mq: Add blk_mq_delay_run_hw_queues() API call

We have:
* blk_mq_run_hw_queue()
* blk_mq_delay_run_hw_queue()
* blk_mq_run_hw_queues()

...but not blk_mq_delay_run_hw_queues(), presumably because nobody
needed it before now.  Since we need it for a later patch in this
series, add it.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1c4bedf..cf95e8e 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1546,6 +1546,25 @@ void blk_mq_run_hw_queues(struct request_queue *q, bool async)
 EXPORT_SYMBOL(blk_mq_run_hw_queues);
 
 /**
+ * blk_mq_delay_run_hw_queues - Run all hardware queues asynchronously.
+ * @q: Pointer to the request queue to run.
+ * @msecs: Microseconds of delay to wait before running the queues.
+ */
+void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs)
+{
+       struct blk_mq_hw_ctx *hctx;
+       int i;
+
+       queue_for_each_hw_ctx(q, hctx, i) {
+               if (blk_mq_hctx_stopped(hctx))
+                       continue;
+
+               blk_mq_delay_run_hw_queue(hctx, msecs);
+       }
+}
+EXPORT_SYMBOL(blk_mq_delay_run_hw_queues);
+
+/**
  * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped
  * @q: request queue.
  *

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index b45148b..51fbf6f 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -508,6 +508,7 @@ void blk_mq_unquiesce_queue(struct request_queue *q);
 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
+void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs);
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
                busy_tag_iter_fn *fn, void *priv);
 void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset);