diff options
author | Jens Axboe <axboe@fb.com> | 2017-01-17 16:03:22 +0300 |
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committer | Jens Axboe <axboe@fb.com> | 2017-01-17 20:04:20 +0300 |
commit | bd166ef183c263c5ced656d49ef19c7da4adc774 (patch) | |
tree | 449bbd3b4e671b370b96e3846b2281116e7089e9 /include/linux/elevator.h | |
parent | 2af8cbe30531eca73c8f3ba277f155fc0020b01a (diff) | |
download | linux-bd166ef183c263c5ced656d49ef19c7da4adc774.tar.xz |
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 <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Diffstat (limited to 'include/linux/elevator.h')
-rw-r--r-- | include/linux/elevator.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 2a9e966eed03..ecb96fd67c6d 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -77,6 +77,34 @@ struct elevator_ops elevator_registered_fn *elevator_registered_fn; }; +struct blk_mq_alloc_data; +struct blk_mq_hw_ctx; + +struct elevator_mq_ops { + int (*init_sched)(struct request_queue *, struct elevator_type *); + void (*exit_sched)(struct elevator_queue *); + + bool (*allow_merge)(struct request_queue *, struct request *, struct bio *); + bool (*bio_merge)(struct blk_mq_hw_ctx *, struct bio *); + int (*request_merge)(struct request_queue *q, struct request **, struct bio *); + void (*request_merged)(struct request_queue *, struct request *, int); + void (*requests_merged)(struct request_queue *, struct request *, struct request *); + struct request *(*get_request)(struct request_queue *, unsigned int, struct blk_mq_alloc_data *); + void (*put_request)(struct request *); + void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool); + void (*dispatch_requests)(struct blk_mq_hw_ctx *, struct list_head *); + bool (*has_work)(struct blk_mq_hw_ctx *); + void (*completed_request)(struct blk_mq_hw_ctx *, struct request *); + void (*started_request)(struct request *); + void (*requeue_request)(struct request *); + struct request *(*former_request)(struct request_queue *, struct request *); + struct request *(*next_request)(struct request_queue *, struct request *); + int (*get_rq_priv)(struct request_queue *, struct request *); + void (*put_rq_priv)(struct request_queue *, struct request *); + void (*init_icq)(struct io_cq *); + void (*exit_icq)(struct io_cq *); +}; + #define ELV_NAME_MAX (16) struct elv_fs_entry { @@ -96,12 +124,14 @@ struct elevator_type /* fields provided by elevator implementation */ union { struct elevator_ops sq; + struct elevator_mq_ops mq; } ops; size_t icq_size; /* see iocontext.h */ size_t icq_align; /* ditto */ struct elv_fs_entry *elevator_attrs; char elevator_name[ELV_NAME_MAX]; struct module *elevator_owner; + bool uses_mq; /* managed by elevator core */ char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */ @@ -125,6 +155,7 @@ struct elevator_queue struct kobject kobj; struct mutex sysfs_lock; unsigned int registered:1; + unsigned int uses_mq:1; DECLARE_HASHTABLE(hash, ELV_HASH_BITS); }; @@ -141,6 +172,7 @@ extern void elv_merge_requests(struct request_queue *, struct request *, extern void elv_merged_request(struct request_queue *, struct request *, int); extern void elv_bio_merged(struct request_queue *q, struct request *, struct bio *); +extern bool elv_attempt_insert_merge(struct request_queue *, struct request *); extern void elv_requeue_request(struct request_queue *, struct request *); extern struct request *elv_former_request(struct request_queue *, struct request *); extern struct request *elv_latter_request(struct request_queue *, struct request *); |