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authorBart Van Assche <bart.vanassche@sandisk.com>2017-04-07 11:16:52 -0700
committerJens Axboe <axboe@fb.com>2017-04-07 12:27:06 -0600
commit7587a5ae7eef0439f7be31f1b5959af062bbc5ec (patch)
treee93068ad849c63192765dcb8ea4d1410f70eeda2
parentebe8bddb6e30d7a02775b9972099271fc5910f37 (diff)
downloadlwn-7587a5ae7eef0439f7be31f1b5959af062bbc5ec.tar.gz
lwn-7587a5ae7eef0439f7be31f1b5959af062bbc5ec.zip
blk-mq: Introduce blk_mq_delay_run_hw_queue()
Introduce a function that runs a hardware queue unconditionally after a delay. Note: there is already a function that stops and restarts a hardware queue after a delay, namely blk_mq_delay_queue(). This function will be used in the next patch in this series. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Long Li <longli@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Jens Axboe <axboe@fb.com>
-rw-r--r--block/blk-mq.c32
-rw-r--r--include/linux/blk-mq.h2
2 files changed, 32 insertions, 2 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f1be5c3eb600..ad45ae743186 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1135,7 +1135,8 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
return hctx->next_cpu;
}
-void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
+static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async,
+ unsigned long msecs)
{
if (unlikely(blk_mq_hctx_stopped(hctx) ||
!blk_mq_hw_queue_mapped(hctx)))
@@ -1152,7 +1153,24 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
put_cpu();
}
- kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work);
+ if (msecs == 0)
+ kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx),
+ &hctx->run_work);
+ else
+ kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
+ &hctx->delayed_run_work,
+ msecs_to_jiffies(msecs));
+}
+
+void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
+{
+ __blk_mq_delay_run_hw_queue(hctx, true, msecs);
+}
+EXPORT_SYMBOL(blk_mq_delay_run_hw_queue);
+
+void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
+{
+ __blk_mq_delay_run_hw_queue(hctx, async, 0);
}
void blk_mq_run_hw_queues(struct request_queue *q, bool async)
@@ -1255,6 +1273,15 @@ static void blk_mq_run_work_fn(struct work_struct *work)
__blk_mq_run_hw_queue(hctx);
}
+static void blk_mq_delayed_run_work_fn(struct work_struct *work)
+{
+ struct blk_mq_hw_ctx *hctx;
+
+ hctx = container_of(work, struct blk_mq_hw_ctx, delayed_run_work.work);
+
+ __blk_mq_run_hw_queue(hctx);
+}
+
static void blk_mq_delay_work_fn(struct work_struct *work)
{
struct blk_mq_hw_ctx *hctx;
@@ -1962,6 +1989,7 @@ static int blk_mq_init_hctx(struct request_queue *q,
node = hctx->numa_node = set->numa_node;
INIT_WORK(&hctx->run_work, blk_mq_run_work_fn);
+ INIT_DELAYED_WORK(&hctx->delayed_run_work, blk_mq_delayed_run_work_fn);
INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
spin_lock_init(&hctx->lock);
INIT_LIST_HEAD(&hctx->dispatch);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index b296a9006117..9382c5da7a2e 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -51,6 +51,7 @@ struct blk_mq_hw_ctx {
atomic_t nr_active;
+ struct delayed_work delayed_run_work;
struct delayed_work delay_work;
struct hlist_node cpuhp_dead;
@@ -238,6 +239,7 @@ void blk_mq_stop_hw_queues(struct request_queue *q);
void blk_mq_start_hw_queues(struct request_queue *q);
void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
+void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
void blk_mq_run_hw_queues(struct request_queue *q, bool async);
void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,