[PATCH v3 2/4] blk-mq: Add blk_mq_delay_run_hw_queues() API call

From: Douglas Anderson
Date: Tue Apr 07 2020 - 18:00:44 EST


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@xxxxxxxxxxxx>
---

Changes in v3:
- ("blk-mq: Add blk_mq_delay_run_hw_queues() API call") new for v3

Changes in v2: None

block/blk-mq.c | 19 +++++++++++++++++++
include/linux/blk-mq.h | 1 +
2 files changed, 20 insertions(+)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7d5f388b7da9..f0a89109fb6d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1544,6 +1544,25 @@ 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 f389d7c724bd..3bbc730eca72 100644
--- 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);
--
2.26.0.292.g33ef6b2f38-goog