From 70f4db639c5b2479e08657392cbf3ba3cceea11c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 16 Apr 2014 10:48:08 -0600 Subject: [PATCH] blk-mq: add blk_mq_delay_queue Add a blk-mq equivalent to blk_delay_queue so that the scsi layer can ask to be kicked again after a delay. Signed-off-by: Christoph Hellwig Modified by me to kill the unnecessary preempt disable/enable in the delayed workqueue handler. Signed-off-by: Jens Axboe --- block/blk-core.c | 6 ++++-- block/blk-mq.c | 45 ++++++++++++++++++++++++++++++++++++------ include/linux/blk-mq.h | 4 +++- 3 files changed, 46 insertions(+), 9 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index ae6227fd07aa..90b6e63b8769 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -251,8 +251,10 @@ void blk_sync_queue(struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i; - queue_for_each_hw_ctx(q, hctx, i) - cancel_delayed_work_sync(&hctx->delayed_work); + queue_for_each_hw_ctx(q, hctx, i) { + cancel_delayed_work_sync(&hctx->run_work); + cancel_delayed_work_sync(&hctx->delay_work); + } } else { cancel_delayed_work_sync(&q->delay_work); } diff --git a/block/blk-mq.c b/block/blk-mq.c index da3808823e44..0cf52dddfa6b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -640,7 +640,7 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) __blk_mq_run_hw_queue(hctx); else if (hctx->queue->nr_hw_queues == 1) - kblockd_schedule_delayed_work(&hctx->delayed_work, 0); + kblockd_schedule_delayed_work(&hctx->run_work, 0); else { unsigned int cpu; @@ -651,7 +651,7 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) * just queue on the first CPU. */ cpu = cpumask_first(hctx->cpumask); - kblockd_schedule_delayed_work_on(cpu, &hctx->delayed_work, 0); + kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0); } } @@ -675,7 +675,8 @@ EXPORT_SYMBOL(blk_mq_run_queues); void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) { - cancel_delayed_work(&hctx->delayed_work); + cancel_delayed_work(&hctx->run_work); + cancel_delayed_work(&hctx->delay_work); set_bit(BLK_MQ_S_STOPPED, &hctx->state); } EXPORT_SYMBOL(blk_mq_stop_hw_queue); @@ -717,15 +718,46 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) } EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); -static void blk_mq_work_fn(struct work_struct *work) +static void blk_mq_run_work_fn(struct work_struct *work) { struct blk_mq_hw_ctx *hctx; - hctx = container_of(work, struct blk_mq_hw_ctx, delayed_work.work); + hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); __blk_mq_run_hw_queue(hctx); } +static void blk_mq_delay_work_fn(struct work_struct *work) +{ + struct blk_mq_hw_ctx *hctx; + + hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); + + if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) + __blk_mq_run_hw_queue(hctx); +} + +void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) +{ + unsigned long tmo = msecs_to_jiffies(msecs); + + if (hctx->queue->nr_hw_queues == 1) + kblockd_schedule_delayed_work(&hctx->delay_work, tmo); + else { + unsigned int cpu; + + /* + * It'd be great if the workqueue API had a way to pass + * in a mask and had some smarts for more clever placement + * than the first CPU. Or we could round-robin here. For now, + * just queue on the first CPU. + */ + cpu = cpumask_first(hctx->cpumask); + kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo); + } +} +EXPORT_SYMBOL(blk_mq_delay_queue); + static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, bool at_head) { @@ -1179,7 +1211,8 @@ static int blk_mq_init_hw_queues(struct request_queue *q, if (node == NUMA_NO_NODE) node = hctx->numa_node = set->numa_node; - INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn); + INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); + INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); spin_lock_init(&hctx->lock); INIT_LIST_HEAD(&hctx->dispatch); hctx->queue = q; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 9ecfab96d8c9..ae868e77bc2f 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -18,7 +18,8 @@ struct blk_mq_hw_ctx { } ____cacheline_aligned_in_smp; unsigned long state; /* BLK_MQ_S_* flags */ - struct delayed_work delayed_work; + struct delayed_work run_work; + struct delayed_work delay_work; cpumask_var_t cpumask; unsigned long flags; /* BLK_MQ_F_* flags */ @@ -158,6 +159,7 @@ void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx); void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx); void blk_mq_stop_hw_queues(struct request_queue *q); void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async); +void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs); /* * Driver command data is immediately after the request. So subtract request