path: root/block/blk-mq.h
diff options
authorJens Axboe <>2017-01-17 06:03:22 -0700
committerJens Axboe <>2017-01-17 10:04:20 -0700
commitbd166ef183c263c5ced656d49ef19c7da4adc774 (patch)
tree449bbd3b4e671b370b96e3846b2281116e7089e9 /block/blk-mq.h
parent2af8cbe30531eca73c8f3ba277f155fc0020b01a (diff)
blk-mq-sched: add framework for MQ capable IO schedulers
This adds a set of hooks that intercepts the blk-mq path of allocating/inserting/issuing/completing requests, allowing us to develop a scheduler within that framework. We reuse the existing elevator scheduler API on the registration side, but augment that with the scheduler flagging support for the blk-mq interfce, and with a separate set of ops hooks for MQ devices. We split driver and scheduler tags, so we can run the scheduling independently of device queue depth. Signed-off-by: Jens Axboe <> Reviewed-by: Bart Van Assche <> Reviewed-by: Omar Sandoval <>
Diffstat (limited to 'block/blk-mq.h')
1 files changed, 7 insertions, 1 deletions
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 1b279b02d0f6..0c7c034d9ddd 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -52,6 +52,8 @@ int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
bool at_head);
+void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+ struct list_head *list);
* CPU hotplug helpers
@@ -124,6 +126,9 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
+ if (data->flags & BLK_MQ_REQ_INTERNAL)
+ return data->hctx->sched_tags;
return data->hctx->tags;
@@ -132,8 +137,9 @@ static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data
void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
struct request *rq, unsigned int op);
-void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
struct request *rq);
+void blk_mq_finish_request(struct request *rq);
struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
unsigned int op);