[PATCH V2 2/5] blk-mq: introduce blk_mq_get_queue_depth()
From: Ming Lei <hidden>
Date: 2017-05-03 19:59:12
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
The hardware queue depth can be resized via blk_mq_update_nr_requests(), so introduce this helper for retrieving queue's depth easily. Signed-off-by: Ming Lei <redacted> --- block/blk-mq.c | 12 ++++++++++++ block/blk-mq.h | 1 + 2 files changed, 13 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 095099df041f..be475ad112ec 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -2120,6 +2120,18 @@ static void blk_mq_map_swqueue(struct request_queue *q, } } +/* + * Queue depth can be changed via blk_mq_update_nr_requests(), + * so use this helper to retrieve queue's depth. + */ +int blk_mq_get_queue_depth(struct request_queue *q) +{ + /* All queues have same queue depth */ + struct blk_mq_tags *tags = q->tag_set->tags[0]; + + return tags->bitmap_tags.sb.depth + tags->breserved_tags.sb.depth; +} + static void queue_set_hctx_shared(struct request_queue *q, bool shared) { struct blk_mq_hw_ctx *hctx;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 2814a14e529c..8085d5989cf5 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h@@ -166,6 +166,7 @@ void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, void blk_mq_finish_request(struct request *rq); struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, unsigned int op); +int blk_mq_get_queue_depth(struct request_queue *q); static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx) {
--
2.9.3