From bd166ef183c263c5ced656d49ef19c7da4adc774 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 17 Jan 2017 06:03:22 -0700 Subject: 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 --- block/blk-mq-sched.h | 170 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 170 insertions(+) create mode 100644 block/blk-mq-sched.h (limited to 'block/blk-mq-sched.h') diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h new file mode 100644 index 000000000000..35c49e2e008a --- /dev/null +++ b/block/blk-mq-sched.h @@ -0,0 +1,170 @@ +#ifndef BLK_MQ_SCHED_H +#define BLK_MQ_SCHED_H + +#include "blk-mq.h" +#include "blk-mq-tag.h" + +int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size, + int (*init)(struct blk_mq_hw_ctx *), + void (*exit)(struct blk_mq_hw_ctx *)); + +void blk_mq_sched_free_hctx_data(struct request_queue *q, + void (*exit)(struct blk_mq_hw_ctx *)); + +struct request *blk_mq_sched_get_request(struct request_queue *q, struct bio *bio, unsigned int op, struct blk_mq_alloc_data *data); +void blk_mq_sched_put_request(struct request *rq); + +void blk_mq_sched_request_inserted(struct request *rq); +bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, struct request *rq); +bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio); +bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio); +bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq); + +void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx); +void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, + struct list_head *rq_list, + struct request *(*get_rq)(struct blk_mq_hw_ctx *)); + +int blk_mq_sched_setup(struct request_queue *q); +void blk_mq_sched_teardown(struct request_queue *q); + +static inline bool +blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) +{ + struct elevator_queue *e = q->elevator; + + if (!e || blk_queue_nomerges(q) || !bio_mergeable(bio)) + return false; + + return __blk_mq_sched_bio_merge(q, bio); +} + +static inline int blk_mq_sched_get_rq_priv(struct request_queue *q, + struct request *rq) +{ + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.get_rq_priv) + return e->type->ops.mq.get_rq_priv(q, rq); + + return 0; +} + +static inline void blk_mq_sched_put_rq_priv(struct request_queue *q, + struct request *rq) +{ + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.put_rq_priv) + e->type->ops.mq.put_rq_priv(q, rq); +} + +static inline void +blk_mq_sched_insert_request(struct request *rq, bool at_head, bool run_queue, + bool async) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + struct blk_mq_ctx *ctx = rq->mq_ctx; + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); + + if (e && e->type->ops.mq.insert_requests) { + LIST_HEAD(list); + + list_add(&rq->queuelist, &list); + e->type->ops.mq.insert_requests(hctx, &list, at_head); + } else { + spin_lock(&ctx->lock); + __blk_mq_insert_request(hctx, rq, at_head); + spin_unlock(&ctx->lock); + } + + if (run_queue) + blk_mq_run_hw_queue(hctx, async); +} + +static inline void +blk_mq_sched_insert_requests(struct request_queue *q, struct blk_mq_ctx *ctx, + struct list_head *list, bool run_queue_async) +{ + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); + struct elevator_queue *e = hctx->queue->elevator; + + if (e && e->type->ops.mq.insert_requests) + e->type->ops.mq.insert_requests(hctx, list, false); + else + blk_mq_insert_requests(hctx, ctx, list); + + blk_mq_run_hw_queue(hctx, run_queue_async); +} + +static inline bool +blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq, + struct bio *bio) +{ + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.allow_merge) + return e->type->ops.mq.allow_merge(q, rq, bio); + + return true; +} + +static inline void +blk_mq_sched_completed_request(struct blk_mq_hw_ctx *hctx, struct request *rq) +{ + struct elevator_queue *e = hctx->queue->elevator; + + if (e && e->type->ops.mq.completed_request) + e->type->ops.mq.completed_request(hctx, rq); + + BUG_ON(rq->internal_tag == -1); + + blk_mq_put_tag(hctx, hctx->sched_tags, rq->mq_ctx, rq->internal_tag); + + if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { + clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); + blk_mq_run_hw_queue(hctx, true); + } +} + +static inline void blk_mq_sched_started_request(struct request *rq) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.started_request) + e->type->ops.mq.started_request(rq); +} + +static inline void blk_mq_sched_requeue_request(struct request *rq) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.requeue_request) + e->type->ops.mq.requeue_request(rq); +} + +static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx) +{ + struct elevator_queue *e = hctx->queue->elevator; + + if (e && e->type->ops.mq.has_work) + return e->type->ops.mq.has_work(hctx); + + return false; +} + +static inline void blk_mq_sched_mark_restart(struct blk_mq_hw_ctx *hctx) +{ + if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) + set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); +} + +static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx) +{ + return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); +} + +#endif -- cgit