Add Kconfig entries to manage what devices get assigned an MQ scheduler, and add a blk-mq flag for drivers to opt out of scheduling. The latter is useful for admin type queues that still allocate a blk-mq queue and tag set, but aren't use for normal IO. Signed-off-by: Jens Axboe <axboe@xxxxxx> --- block/Kconfig.iosched | 43 +++++++++++++++++++++++++++++++++++++------ block/blk-mq-sched.c | 19 +++++++++++++++++++ block/blk-mq-sched.h | 2 ++ block/blk-mq.c | 3 +++ block/elevator.c | 5 ++++- drivers/nvme/host/pci.c | 1 + include/linux/blk-mq.h | 1 + 7 files changed, 67 insertions(+), 7 deletions(-) diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched index 490ef2850fae..96216cf18560 100644 --- a/block/Kconfig.iosched +++ b/block/Kconfig.iosched @@ -32,12 +32,6 @@ config IOSCHED_CFQ This is the default I/O scheduler. -config MQ_IOSCHED_DEADLINE - tristate "MQ deadline I/O scheduler" - default y - ---help--- - MQ version of the deadline IO scheduler. - config CFQ_GROUP_IOSCHED bool "CFQ Group Scheduling support" depends on IOSCHED_CFQ && BLK_CGROUP @@ -69,6 +63,43 @@ config DEFAULT_IOSCHED default "cfq" if DEFAULT_CFQ default "noop" if DEFAULT_NOOP +config MQ_IOSCHED_DEADLINE + tristate "MQ deadline I/O scheduler" + default y + ---help--- + MQ version of the deadline IO scheduler. + +config MQ_IOSCHED_NONE + bool + default y + +choice + prompt "Default MQ I/O scheduler" + default MQ_IOSCHED_NONE + help + Select the I/O scheduler which will be used by default for all + blk-mq managed block devices. + + config DEFAULT_MQ_DEADLINE + bool "MQ Deadline" if MQ_IOSCHED_DEADLINE=y + + config DEFAULT_MQ_NONE + bool "None" + +endchoice + +config DEFAULT_MQ_IOSCHED + string + default "mq-deadline" if DEFAULT_MQ_DEADLINE + default "none" if DEFAULT_MQ_NONE + +config MQ_IOSCHED_ONLY_SQ + bool "Enable blk-mq IO scheduler only for single queue devices" + default y + help + Say Y here, if you only want to enable IO scheduling on block + devices that have a single queue registered. + endmenu endif diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index b7e1839d4785..1f06efcdaa2d 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -432,3 +432,22 @@ void blk_mq_sched_request_inserted(struct request *rq) trace_block_rq_insert(rq->q, rq); } EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); + +int blk_mq_sched_init(struct request_queue *q) +{ + int ret; + +#if defined(CONFIG_DEFAULT_MQ_NONE) + return 0; +#endif +#if defined(CONFIG_MQ_IOSCHED_ONLY_SQ) + if (q->nr_hw_queues > 1) + return 0; +#endif + + mutex_lock(&q->sysfs_lock); + ret = elevator_init(q, NULL); + mutex_unlock(&q->sysfs_lock); + + return ret; +} diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 1d1a4e9ce6ca..826f3e6991e3 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -37,6 +37,8 @@ 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); +int blk_mq_sched_init(struct request_queue *q); + static inline bool blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) { diff --git a/block/blk-mq.c b/block/blk-mq.c index 032dca4a27bf..0d8ea45b8562 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2105,6 +2105,9 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, INIT_LIST_HEAD(&q->requeue_list); spin_lock_init(&q->requeue_lock); + if (!(set->flags & BLK_MQ_F_NO_SCHED)) + blk_mq_sched_init(q); + if (q->nr_hw_queues > 1) blk_queue_make_request(q, blk_mq_make_request); else diff --git a/block/elevator.c b/block/elevator.c index e6b523360231..eb34c26f675f 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -219,7 +219,10 @@ int elevator_init(struct request_queue *q, char *name) } if (!e) { - e = elevator_get(CONFIG_DEFAULT_IOSCHED, false); + if (q->mq_ops) + e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false); + else + e = elevator_get(CONFIG_DEFAULT_IOSCHED, false); if (!e) { printk(KERN_ERR "Default I/O scheduler not found. " \ diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index d6e6bce93d0c..063410d9b3cc 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1188,6 +1188,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev) dev->admin_tagset.timeout = ADMIN_TIMEOUT; dev->admin_tagset.numa_node = dev_to_node(dev->dev); dev->admin_tagset.cmd_size = nvme_cmd_size(dev); + dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED; dev->admin_tagset.driver_data = dev; if (blk_mq_alloc_tag_set(&dev->admin_tagset)) diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index e3159be841ff..9255ccb043f2 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -152,6 +152,7 @@ enum { BLK_MQ_F_SG_MERGE = 1 << 2, BLK_MQ_F_DEFER_ISSUE = 1 << 4, BLK_MQ_F_BLOCKING = 1 << 5, + BLK_MQ_F_NO_SCHED = 1 << 6, BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, BLK_MQ_F_ALLOC_POLICY_BITS = 1, -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html