Release 4.7 block/blk-mq.c

Directory: block
/*
 * Block multiqueue core code
 *
 * Copyright (C) 2013-2014 Jens Axboe
 * Copyright (C) 2013-2014 Christoph Hellwig
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/backing-dev.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/kmemleak.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/smp.h>
#include <linux/llist.h>
#include <linux/list_sort.h>
#include <linux/cpu.h>
#include <linux/cache.h>
#include <linux/sched/sysctl.h>
#include <linux/delay.h>
#include <linux/crash_dump.h>

#include <trace/events/block.h>

#include <linux/blk-mq.h>
#include "blk.h"
#include "blk-mq.h"
#include "blk-mq-tag.h"

static DEFINE_MUTEX(all_q_mutex);
static LIST_HEAD(all_q_list);

static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx);

/*
 * Check if any of the ctx's have pending work in this hardware queue
 */


static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
{
	unsigned int i;

	for (i = 0; i < hctx->ctx_map.size; i++)
		if (hctx->ctx_map.map[i].word)
			return true;

	return false;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 51 100.00% 3 100.00%
Total 51 100.00% 3 100.00%



static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx,
					      struct blk_mq_ctx *ctx)
{
	return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word];
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 38 100.00% 1 100.00%
Total 38 100.00% 1 100.00%


#define CTX_TO_BIT(hctx, ctx)	\
	((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1))

/*
 * Mark this ctx as having pending work in this hardware queue
 */


static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
				     struct blk_mq_ctx *ctx)
{
	struct blk_align_bitmap *bm = get_bm(hctx, ctx);

	if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word))
		set_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 61 100.00% 2 100.00%
Total 61 100.00% 2 100.00%



static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
				      struct blk_mq_ctx *ctx)
{
	struct blk_align_bitmap *bm = get_bm(hctx, ctx);

	clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 43 100.00% 2 100.00%
Total 43 100.00% 2 100.00%



void blk_mq_freeze_queue_start(struct request_queue *q)
{
	int freeze_depth;

	freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
	if (freeze_depth == 1) {
		percpu_ref_kill(&q->q_usage_counter);
		blk_mq_run_hw_queues(q, false);
	}
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 17 36.96% 1 11.11%
tejun heo tejun heo 16 34.78% 5 55.56%
christoph hellwig christoph hellwig 9 19.57% 1 11.11%
mike snitzer mike snitzer 3 6.52% 1 11.11%
dan williams dan williams 1 2.17% 1 11.11%
Total 46 100.00% 9 100.00%


EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);



static void blk_mq_freeze_queue_wait(struct request_queue *q)
{
	wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
}

Contributors
Person Tokens Prop Commits CommitProp
tejun heo tejun heo 16 61.54% 2 40.00%
lei ming lei ming 6 23.08% 1 20.00%
jens axboe jens axboe 3 11.54% 1 20.00%
dan williams dan williams 1 3.85% 1 20.00%
Total 26 100.00% 5 100.00%

/*
 * Guarantee no request is in use, so we can change any data structure of
 * the queue afterward.
 */


void blk_freeze_queue(struct request_queue *q)
{
	/*
         * In the !blk_mq case we are only calling this to kill the
         * q_usage_counter, otherwise this increases the freeze depth
         * and waits for it to return to zero.  For this reason there is
         * no blk_unfreeze_queue(), and blk_freeze_queue() is not
         * exported to drivers as the only user for unfreeze is blk_mq.
         */
	blk_mq_freeze_queue_start(q);
	blk_mq_freeze_queue_wait(q);
}

Contributors
Person Tokens Prop Commits CommitProp
tejun heo tejun heo 19 90.48% 1 50.00%
dan williams dan williams 2 9.52% 1 50.00%
Total 21 100.00% 2 100.00%



void blk_mq_freeze_queue(struct request_queue *q)
{
	/*
         * ...just an alias to keep freeze and unfreeze actions balanced
         * in the blk_mq_* namespace
         */
	blk_freeze_queue(q);
}
Contributors
Person Tokens Prop Commits CommitProp
dan williams dan williams 16 100.00% 1 100.00%
Total 16 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);



void blk_mq_unfreeze_queue(struct request_queue *q)
{
	int freeze_depth;

	freeze_depth = atomic_dec_return(&q->mq_freeze_depth);
	WARN_ON_ONCE(freeze_depth < 0);
	if (!freeze_depth) {
		percpu_ref_reinit(&q->q_usage_counter);
		wake_up_all(&q->mq_freeze_wq);
	}
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 31 58.49% 1 20.00%
tejun heo tejun heo 11 20.75% 2 40.00%
christoph hellwig christoph hellwig 10 18.87% 1 20.00%
dan williams dan williams 1 1.89% 1 20.00%
Total 53 100.00% 5 100.00%


EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);



void blk_mq_wake_waiters(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned int i;

	queue_for_each_hw_ctx(q, hctx, i)
		if (blk_mq_hw_queue_mapped(hctx))
			blk_mq_tag_wakeup_all(hctx->tags, true);

	/*
         * If we are called because the queue has now been marked as
         * dying, we need to ensure that processes currently waiting on
         * the queue are notified as well.
         */
	wake_up_all(&q->mq_freeze_wq);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 43 82.69% 1 50.00%
keith busch keith busch 9 17.31% 1 50.00%
Total 52 100.00% 2 100.00%



bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
{
	return blk_mq_has_free_tags(hctx->tags);
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 18 100.00% 1 100.00%
Total 18 100.00% 1 100.00%


EXPORT_SYMBOL(blk_mq_can_queue);



static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
			       struct request *rq, unsigned int rw_flags)
{
	if (blk_queue_io_stat(q))
		rw_flags |= REQ_IO_STAT;

	INIT_LIST_HEAD(&rq->queuelist);
	/* csd/requeue_work/fifo_time is initialized before use */
	rq->q = q;
	rq->mq_ctx = ctx;
	rq->cmd_flags |= rw_flags;
	/* do not touch atomic flags, it needs atomic ops against the timer */
	rq->cpu = -1;
	INIT_HLIST_NODE(&rq->hash);
	RB_CLEAR_NODE(&rq->rb_node);
	rq->rq_disk = NULL;
	rq->part = NULL;
	rq->start_time = jiffies;
#ifdef CONFIG_BLK_CGROUP
	rq->rl = NULL;
	set_start_time_ns(rq);
	rq->io_start_time_ns = 0;
#endif
	rq->nr_phys_segments = 0;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
	rq->nr_integrity_segments = 0;
#endif
	rq->special = NULL;
	/* tag was already set */
	rq->errors = 0;

	rq->cmd = rq->__cmd;

	rq->extra_len = 0;
	rq->sense_len = 0;
	rq->resid_len = 0;
	rq->sense = NULL;

	INIT_LIST_HEAD(&rq->timeout_list);
	rq->timeout = 0;

	rq->end_io = NULL;
	rq->end_io_data = NULL;
	rq->next_rq = NULL;

	ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
}

Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 151 64.26% 1 12.50%
jens axboe jens axboe 71 30.21% 5 62.50%
tony battersby tony battersby 8 3.40% 1 12.50%
lei ming lei ming 5 2.13% 1 12.50%
Total 235 100.00% 8 100.00%


static struct request *

__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw)
{
	struct request *rq;
	unsigned int tag;

	tag = blk_mq_get_tag(data);
	if (tag != BLK_MQ_TAG_FAIL) {
		rq = data->hctx->tags->rqs[tag];

		if (blk_mq_tag_busy(data->hctx)) {
			rq->cmd_flags = REQ_MQ_INFLIGHT;
			atomic_inc(&data->hctx->nr_active);
		}

		rq->tag = tag;
		blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw);
		return rq;
	}

	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 94 87.85% 1 50.00%
lei ming lei ming 13 12.15% 1 50.00%
Total 107 100.00% 2 100.00%



struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
		unsigned int flags)
{
	struct blk_mq_ctx *ctx;
	struct blk_mq_hw_ctx *hctx;
	struct request *rq;
	struct blk_mq_alloc_data alloc_data;
	int ret;

	ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT);
	if (ret)
		return ERR_PTR(ret);

	ctx = blk_mq_get_ctx(q);
	hctx = q->mq_ops->map_queue(q, ctx->cpu);
	blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);

	rq = __blk_mq_alloc_request(&alloc_data, rw);
	if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) {
		__blk_mq_run_hw_queue(hctx);
		blk_mq_put_ctx(ctx);

		ctx = blk_mq_get_ctx(q);
		hctx = q->mq_ops->map_queue(q, ctx->cpu);
		blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
		rq =  __blk_mq_alloc_request(&alloc_data, rw);
		ctx = alloc_data.ctx;
	}
	blk_mq_put_ctx(ctx);
	if (!rq) {
		blk_queue_exit(q);
		return ERR_PTR(-EWOULDBLOCK);
	}
	return rq;
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 71 33.65% 3 25.00%
christoph hellwig christoph hellwig 63 29.86% 4 33.33%
lei ming lei ming 43 20.38% 1 8.33%
joe lawrence joe lawrence 25 11.85% 1 8.33%
keith busch keith busch 7 3.32% 2 16.67%
dan williams dan williams 2 0.95% 1 8.33%
Total 211 100.00% 12 100.00%


EXPORT_SYMBOL(blk_mq_alloc_request);



static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
				  struct blk_mq_ctx *ctx, struct request *rq)
{
	const int tag = rq->tag;
	struct request_queue *q = rq->q;

	if (rq->cmd_flags & REQ_MQ_INFLIGHT)
		atomic_dec(&hctx->nr_active);
	rq->cmd_flags = 0;

	clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
	blk_mq_put_tag(hctx, tag, &ctx->last_tag);
	blk_queue_exit(q);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 70 80.46% 3 50.00%
christoph hellwig christoph hellwig 10 11.49% 1 16.67%
david hildenbrand david hildenbrand 6 6.90% 1 16.67%
dan williams dan williams 1 1.15% 1 16.67%
Total 87 100.00% 6 100.00%



void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq)
{
	struct blk_mq_ctx *ctx = rq->mq_ctx;

	ctx->rq_completed[rq_is_sync(rq)]++;
	__blk_mq_free_request(hctx, ctx, rq);

}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 44 100.00% 2 100.00%
Total 44 100.00% 2 100.00%


EXPORT_SYMBOL_GPL(blk_mq_free_hctx_request);



void blk_mq_free_request(struct request *rq)
{
	struct blk_mq_hw_ctx *hctx;
	struct request_queue *q = rq->q;

	hctx = q->mq_ops->map_queue(q, rq->mq_ctx->cpu);
	blk_mq_free_hctx_request(hctx, rq);
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 48 100.00% 2 100.00%
Total 48 100.00% 2 100.00%


EXPORT_SYMBOL_GPL(blk_mq_free_request);



inline void __blk_mq_end_request(struct request *rq, int error)
{
	blk_account_io_done(rq);

	if (rq->end_io) {
		rq->end_io(rq, error);
	} else {
		if (unlikely(blk_bidi_rq(rq)))
			blk_mq_free_request(rq->next_rq);
		blk_mq_free_request(rq);
	}
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 32 52.46% 1 20.00%
christoph hellwig christoph hellwig 24 39.34% 3 60.00%
lei ming lei ming 5 8.20% 1 20.00%
Total 61 100.00% 5 100.00%


EXPORT_SYMBOL(__blk_mq_end_request);



void blk_mq_end_request(struct request *rq, int error)
{
	if (blk_update_request(rq, error, blk_rq_bytes(rq)))
		BUG();
	__blk_mq_end_request(rq, error);
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 37 100.00% 2 100.00%
Total 37 100.00% 2 100.00%


EXPORT_SYMBOL(blk_mq_end_request);



static void __blk_mq_complete_request_remote(void *data)
{
	struct request *rq = data;

	rq->q->softirq_done_fn(rq);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 18 69.23% 1 33.33%
christoph hellwig christoph hellwig 8 30.77% 2 66.67%
Total 26 100.00% 3 100.00%



static void blk_mq_ipi_complete_request(struct request *rq)
{
	struct blk_mq_ctx *ctx = rq->mq_ctx;
	bool shared = false;
	int cpu;

	if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
		rq->q->softirq_done_fn(rq);
		return;
	}

	cpu = get_cpu();
	if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
		shared = cpus_share_cache(cpu, ctx->cpu);

	if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
		rq->csd.func = __blk_mq_complete_request_remote;
		rq->csd.info = rq;
		rq->csd.flags = 0;
		smp_call_function_single_async(ctx->cpu, &rq->csd);
	} else {
		rq->q->softirq_done_fn(rq);
	}
	put_cpu();
}

Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 95 60.51% 3 50.00%
jens axboe jens axboe 61 38.85% 2 33.33%
frederic weisbecker frederic weisbecker 1 0.64% 1 16.67%
Total 157 100.00% 6 100.00%



static void __blk_mq_complete_request(struct request *rq)
{
	struct request_queue *q = rq->q;

	if (!q->softirq_done_fn)
		blk_mq_end_request(rq, rq->errors);
	else
		blk_mq_ipi_complete_request(rq);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 41 97.62% 2 66.67%
christoph hellwig christoph hellwig 1 2.38% 1 33.33%
Total 42 100.00% 3 100.00%

/**
 * blk_mq_complete_request - end I/O on a request
 * @rq:         the request being processed
 *
 * Description:
 *      Ends all I/O on a request. It does not handle partial completions.
 *      The actual completion happens out-of-order, through a IPI handler.
 **/


void blk_mq_complete_request(struct request *rq, int error)
{
	struct request_queue *q = rq->q;

	if (unlikely(blk_should_fake_timeout(q)))
		return;
	if (!blk_mark_rq_complete(rq)) {
		rq->errors = error;
		__blk_mq_complete_request(rq);
	}
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 45 83.33% 2 66.67%
jens axboe jens axboe 9 16.67% 1 33.33%
Total 54 100.00% 3 100.00%


EXPORT_SYMBOL(blk_mq_complete_request);



int blk_mq_request_started(struct request *rq)
{
	return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
}
Contributors
Person Tokens Prop Commits CommitProp
keith busch keith busch 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(blk_mq_request_started);



void blk_mq_start_request(struct request *rq)
{
	struct request_queue *q = rq->q;

	trace_block_rq_issue(q, rq);

	rq->resid_len = blk_rq_bytes(rq);
	if (unlikely(blk_bidi_rq(rq)))
		rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq);

	blk_add_timer(rq);

	/*
         * Ensure that ->deadline is visible before set the started
         * flag and clear the completed flag.
         */
	smp_mb__before_atomic();

	/*
         * Mark us as started and clear complete. Complete might have been
         * set if requeue raced with timeout, which then marked it as
         * complete. So be sure to clear complete again when we start
         * the request, otherwise we'll ignore the completion event.
         */
	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
		set_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
	if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags))
		clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);

	if (q->dma_drain_size && blk_rq_bytes(rq)) {
		/*
                 * Make sure space for the drain appears.  We know we can do
                 * this because max_hw_segments has been adjusted to be one
                 * fewer than the device can handle.
                 */
		rq->nr_phys_segments++;
	}
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 78 59.09% 5 55.56%
christoph hellwig christoph hellwig 51 38.64% 3 33.33%
lei ming lei ming 3 2.27% 1 11.11%
Total 132 100.00% 9 100.00%


EXPORT_SYMBOL(blk_mq_start_request);



static void __blk_mq_requeue_request(struct request *rq)
{
	struct request_queue *q = rq->q;

	trace_block_rq_requeue(q, rq);

	if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
		if (q->dma_drain_size && blk_rq_bytes(rq))
			rq->nr_phys_segments--;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 34 59.65% 1 25.00%
christoph hellwig christoph hellwig 23 40.35% 3 75.00%
Total 57 100.00% 4 100.00%



void blk_mq_requeue_request(struct request *rq)
{
	__blk_mq_requeue_request(rq);

	BUG_ON(blk_queued_rq(rq));
	blk_mq_add_to_requeue_list(rq, true);
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 30 100.00% 2 100.00%
Total 30 100.00% 2 100.00%


EXPORT_SYMBOL(blk_mq_requeue_request);



static void blk_mq_requeue_work(struct work_struct *work)
{
	struct request_queue *q =
		container_of(work, struct request_queue, requeue_work);
	LIST_HEAD(rq_list);
	struct request *rq, *next;
	unsigned long flags;

	spin_lock_irqsave(&q->requeue_lock, flags);
	list_splice_init(&q->requeue_list, &rq_list);
	spin_unlock_irqrestore(&q->requeue_lock, flags);

	list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
		if (!(rq->cmd_flags & REQ_SOFTBARRIER))
			continue;

		rq->cmd_flags &= ~REQ_SOFTBARRIER;
		list_del_init(&rq->queuelist);
		blk_mq_insert_request(rq, true, false, false);
	}

	while (!list_empty(&rq_list)) {
		rq = list_entry(rq_list.next, struct request, queuelist);
		list_del_init(&rq->queuelist);
		blk_mq_insert_request(rq, false, false, false);
	}

	/*
         * Use the start variant of queue running here, so that running
         * the requeue work will kick stopped queues.
         */
	blk_mq_start_hw_queues(q);
}

Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 172 98.85% 2 66.67%
jens axboe jens axboe 2 1.15% 1 33.33%
Total 174 100.00% 3 100.00%



void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
{
	struct request_queue *q = rq->q;
	unsigned long flags;

	/*
         * We abuse this flag that is otherwise used by the I/O scheduler to
         * request head insertation from the workqueue.
         */
	BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER);

	spin_lock_irqsave(&q->requeue_lock, flags);
	if (at_head) {
		rq->cmd_flags |= REQ_SOFTBARRIER;
		list_add(&rq->queuelist, &q->requeue_list);
	} else {
		list_add_tail(&rq->queuelist, &q->requeue_list);
	}
	spin_unlock_irqrestore(&q->requeue_lock, flags);
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 97 100.00% 2 100.00%
Total 97 100.00% 2 100.00%


EXPORT_SYMBOL(blk_mq_add_to_requeue_list);



void blk_mq_cancel_requeue_work(struct request_queue *q)
{
	cancel_work_sync(&q->requeue_work);
}
Contributors
Person Tokens Prop Commits CommitProp
keith busch keith busch 18 100.00% 1 100.00%
Total 18 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(blk_mq_cancel_requeue_work);



void blk_mq_kick_requeue_list(struct request_queue *q)
{
	kblockd_schedule_work(&q->requeue_work);
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 18 100.00% 1 100.00%
Total 18 100.00% 1 100.00%


EXPORT_SYMBOL(blk_mq_kick_requeue_list);



void blk_mq_abort_requeue_list(struct request_queue *q)
{
	unsigned long flags;
	LIST_HEAD(rq_list);

	spin_lock_irqsave(&q->requeue_lock, flags);
	list_splice_init(&q->requeue_list, &rq_list);
	spin_unlock_irqrestore(&q->requeue_lock, flags);

	while (!list_empty(&rq_list)) {
		struct request *rq;

		rq = list_first_entry(&rq_list, struct request, queuelist);
		list_del_init(&rq->queuelist);
		rq->errors = -EIO;
		blk_mq_end_request(rq, rq->errors);
	}
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 103 100.00% 1 100.00%
Total 103 100.00% 1 100.00%


EXPORT_SYMBOL(blk_mq_abort_requeue_list);



struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
{
	if (tag < tags->nr_tags)
		return tags->rqs[tag];

	return NULL;
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 15 42.86% 1 25.00%
hannes reinecke hannes reinecke 11 31.43% 1 25.00%
christoph hellwig christoph hellwig 8 22.86% 1 25.00%
ming lei ming lei 1 2.86% 1 25.00%
Total 35 100.00% 4 100.00%


EXPORT_SYMBOL(blk_mq_tag_to_rq);


struct blk_mq_timeout_data {
	
unsigned long next;
	
unsigned int next_set;
};



void blk_mq_rq_timed_out(struct request *req, bool reserved)
{
	struct blk_mq_ops *ops = req->q->mq_ops;
	enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;

	/*
         * We know that complete is set at this point. If STARTED isn't set
         * anymore, then the request isn't active and the "timeout" should
         * just be ignored. This can happen due to the bitflag ordering.
         * Timeout first checks if STARTED is set, and if it is, assumes
         * the request is active. But if we race with completion, then
         * we both flags will get cleared. So check here again, and ignore
         * a timeout event with a request that isn't active.
         */
	if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
		return;

	if (ops->timeout)
		ret = ops->timeout(req, reserved);

	switch (ret) {
	case BLK_EH_HANDLED:
		__blk_mq_complete_request(req);
		break;
	case BLK_EH_RESET_TIMER:
		blk_add_timer(req);
		blk_clear_rq_complete(req);
		break;
	case BLK_EH_NOT_HANDLED:
		break;
	default:
		printk(KERN_ERR "block: bad eh return: %d\n", ret);
		break;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 69 65.71% 4 66.67%
jens axboe jens axboe 36 34.29% 2 33.33%
Total 105 100.00% 6 100.00%



static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
		struct request *rq, void *priv, bool reserved)
{
	struct blk_mq_timeout_data *data = priv;

	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
		/*
                 * If a request wasn't started before the queue was
                 * marked dying, kill it here or it'll go unnoticed.
                 */
		if (unlikely(blk_queue_dying(rq->q))) {
			rq->errors = -EIO;
			blk_mq_end_request(rq, rq->errors);
		}
		return;
	}

	if (time_after_eq(jiffies, rq->deadline)) {
		if (!blk_mark_rq_complete(rq))
			blk_mq_rq_timed_out(rq, reserved);
	} else if (!data->next_set || time_after(data->next, rq->deadline)) {
		data->next = rq->deadline;
		data->next_set = 1;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 67 47.86% 4 50.00%
jens axboe jens axboe 42 30.00% 2 25.00%
keith busch keith busch 31 22.14% 2 25.00%
Total 140 100.00% 8 100.00%



static void blk_mq_timeout_work(struct work_struct *work)
{
	struct request_queue *q =
		container_of(work, struct request_queue, timeout_work);
	struct blk_mq_timeout_data data = {
		.next		= 0,
		.next_set	= 0,
        };
	int i;

	if (blk_queue_enter(q, true))
		return;

	blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);

	if (data.next_set) {
		data.next = blk_rq_timeout(round_jiffies_up(data.next));
		mod_timer(&q->timeout, data.next);
	} else {
		struct blk_mq_hw_ctx *hctx;

		queue_for_each_hw_ctx(q, hctx, i) {
			/* the hctx may be unmapped, so check it here */
			if (blk_mq_hw_queue_mapped(hctx))
				blk_mq_tag_idle(hctx);
		}
	}
	blk_queue_exit(q);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 66 48.89% 2 33.33%
christoph hellwig christoph hellwig 59 43.70% 3 50.00%
ming lei ming lei 10 7.41% 1 16.67%
Total 135 100.00% 6 100.00%

/*
 * Reverse check our software queue for entries that we could potentially
 * merge with. Currently includes a hand-wavy stop count of 8, to not spend
 * too much time checking for merges.
 */


static bool blk_mq_attempt_merge(struct request_queue *q,
				 struct blk_mq_ctx *ctx, struct bio *bio)
{
	struct request *rq;
	int checked = 8;

	list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
		int el_ret;

		if (!checked--)
			break;

		if (!blk_rq_merge_ok(rq, bio))
			continue;

		el_ret = blk_try_merge(rq, bio);
		if (el_ret == ELEVATOR_BACK_MERGE) {
			if (bio_attempt_back_merge(q, rq, bio)) {
				ctx->rq_merged++;
				return true;
			}
			break;
		} else if (el_ret == ELEVATOR_FRONT_MERGE) {
			if (bio_attempt_front_merge(q, rq, bio)) {
				ctx->rq_merged++;
				return true;
			}
			break;
		}
	}

	return false;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 135 100.00% 1 100.00%
Total 135 100.00% 1 100.00%

/*
 * Process software queues that have been marked busy, splicing them
 * to the for-dispatch
 */


static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
{
	struct blk_mq_ctx *ctx;
	int i;

	for (i = 0; i < hctx->ctx_map.size; i++) {
		struct blk_align_bitmap *bm = &hctx->ctx_map.map[i];
		unsigned int off, bit;

		if (!bm->word)
			continue;

		bit = 0;
		off = i * hctx->ctx_map.bits_per_word;
		do {
			bit = find_next_bit(&bm->word, bm->depth, bit);
			if (bit >= bm->depth)
				break;

			ctx = hctx->ctxs[bit + off];
			clear_bit(bit, &bm->word);
			spin_lock(&ctx->lock);
			list_splice_tail_init(&ctx->rq_list, list);
			spin_unlock(&ctx->lock);

			bit++;
		} while (1);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 169 100.00% 2 100.00%
Total 169 100.00% 2 100.00%

/*
 * Run this hardware queue, pulling any software queues mapped to it in.
 * Note that this function currently has various problems around ordering
 * of IO. In particular, we'd like FIFO behaviour on handling existing
 * items on the hctx->dispatch list. Ignore that for now.
 */


static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
{
	struct request_queue *q = hctx->queue;
	struct request *rq;
	LIST_HEAD(rq_list);
	LIST_HEAD(driver_list);
	struct list_head *dptr;
	int queued;

	WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask));

	if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
		return;

	hctx->run++;

	/*
         * Touch any software queue that has pending entries.
         */
	flush_busy_ctxs(hctx, &rq_list);

	/*
         * If we have previous entries on our dispatch list, grab them
         * and stuff them at the front for more fair dispatch.
         */
	if (!list_empty_careful(&hctx->dispatch)) {
		spin_lock(&hctx->lock);
		if (!list_empty(&hctx->dispatch))
			list_splice_init(&hctx->dispatch, &rq_list);
		spin_unlock(&hctx->lock);
	}

	/*
         * Start off with dptr being NULL, so we start the first request
         * immediately, even if we have more pending.
         */
	dptr = NULL;

	/*
         * Now process all the entries, sending them to the driver.
         */
	queued = 0;
	while (!list_empty(&rq_list)) {
		struct blk_mq_queue_data bd;
		int ret;

		rq = list_first_entry(&rq_list, struct request, queuelist);
		list_del_init(&rq->queuelist);

		bd.rq = rq;
		bd.list = dptr;
		bd.last = list_empty(&rq_list);

		ret = q->mq_ops->queue_rq(hctx, &bd);
		switch (ret) {
		case BLK_MQ_RQ_QUEUE_OK:
			queued++;
			continue;
		case BLK_MQ_RQ_QUEUE_BUSY:
			list_add(&rq->queuelist, &rq_list);
			__blk_mq_requeue_request(rq);
			break;
		default:
			pr_err("blk-mq: bad return on queue: %d\n", ret);
		case BLK_MQ_RQ_QUEUE_ERROR:
			rq->errors = -EIO;
			blk_mq_end_request(rq, rq->errors);
			break;
		}

		if (ret == BLK_MQ_RQ_QUEUE_BUSY)
			break;

		/*
                 * We've done the first request. If we have more than 1
                 * left in the list, set dptr to defer issue.
                 */
		if (!dptr && rq_list.next != rq_list.prev)
			dptr = &driver_list;
	}

	if (!queued)
		hctx->dispatched[0]++;
	else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1)))
		hctx->dispatched[ilog2(queued) + 1]++;

	/*
         * Any items that need requeuing? Stuff them into hctx->dispatch,
         * that is where we will continue on next queue run.
         */
	if (!list_empty(&rq_list)) {
		spin_lock(&hctx->lock);
		list_splice(&rq_list, &hctx->dispatch);
		spin_unlock(&hctx->lock);
		/*
                 * the queue is expected stopped with BLK_MQ_RQ_QUEUE_BUSY, but
                 * it's possible the queue is stopped and restarted again
                 * before this. Queue restart will dispatch requests. And since
                 * requests in rq_list aren't added into hctx->dispatch yet,
                 * the requests in rq_list might get lost.
                 *
                 * blk_mq_run_hw_queue() already checks the STOPPED bit
                 **/
		blk_mq_run_hw_queue(hctx, true);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 385 96.49% 6 54.55%
shaohua li shaohua li 8 2.01% 1 9.09%
christoph hellwig christoph hellwig 6 1.50% 4 36.36%
Total 399 100.00% 11 100.00%

/*
 * It'd be great if the workqueue API had a way to pass
 * in a mask and had some smarts for more clever placement.
 * For now we just round-robin here, switching for every
 * BLK_MQ_CPU_WORK_BATCH queued items.
 */


static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
{
	if (hctx->queue->nr_hw_queues == 1)
		return WORK_CPU_UNBOUND;

	if (--hctx->next_cpu_batch <= 0) {
		int cpu = hctx->next_cpu, next_cpu;

		next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask);
		if (next_cpu >= nr_cpu_ids)
			next_cpu = cpumask_first(hctx->cpumask);

		hctx->next_cpu = next_cpu;
		hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;

		return cpu;
	}

	return hctx->next_cpu;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 69 75.00% 1 50.00%
christoph hellwig christoph hellwig 23 25.00% 1 50.00%
Total 92 100.00% 2 100.00%



void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
{
	if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) ||
	    !blk_mq_hw_queue_mapped(hctx)))
		return;

	if (!async) {
		int cpu = get_cpu();
		if (cpumask_test_cpu(cpu, hctx->cpumask)) {
			__blk_mq_run_hw_queue(hctx);
			put_cpu();
			return;
		}

		put_cpu();
	}

	kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
			&hctx->run_work, 0);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 60 68.18% 4 44.44%
paolo bonzini paolo bonzini 20 22.73% 2 22.22%
ming lei ming lei 6 6.82% 1 11.11%
christoph hellwig christoph hellwig 2 2.27% 2 22.22%
Total 88 100.00% 9 100.00%



void blk_mq_run_hw_queues(struct request_queue *q, bool async)
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	queue_for_each_hw_ctx(q, hctx, i) {
		if ((!blk_mq_hctx_has_pending(hctx) &&
		    list_empty_careful(&hctx->dispatch)) ||
		    test_bit(BLK_MQ_S_STOPPED, &hctx->state))
			continue;

		blk_mq_run_hw_queue(hctx, async);
	}
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 62 92.54% 2 66.67%
mike snitzer mike snitzer 5 7.46% 1 33.33%
Total 67 100.00% 3 100.00%


EXPORT_SYMBOL(blk_mq_run_hw_queues);



void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
{
	cancel_delayed_work(&hctx->run_work);
	cancel_delayed_work(&hctx->delay_work);
	set_bit(BLK_MQ_S_STOPPED, &hctx->state);
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 27 75.00% 1 50.00%
christoph hellwig christoph hellwig 9 25.00% 1 50.00%
Total 36 100.00% 2 100.00%


EXPORT_SYMBOL(blk_mq_stop_hw_queue);



void blk_mq_stop_hw_queues(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	queue_for_each_hw_ctx(q, hctx, i)
		blk_mq_stop_hw_queue(hctx);
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 31 100.00% 1 100.00%
Total 31 100.00% 1 100.00%


EXPORT_SYMBOL(blk_mq_stop_hw_queues);



void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
{
	clear_bit(BLK_MQ_S_STOPPED, &hctx->state);

	blk_mq_run_hw_queue(hctx, false);
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 27 100.00% 2 100.00%
Total 27 100.00% 2 100.00%


EXPORT_SYMBOL(blk_mq_start_hw_queue);



void blk_mq_start_hw_queues(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	queue_for_each_hw_ctx(q, hctx, i)
		blk_mq_start_hw_queue(hctx);
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 31 100.00% 1 100.00%
Total 31 100.00% 1 100.00%


EXPORT_SYMBOL(blk_mq_start_hw_queues);



void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	queue_for_each_hw_ctx(q, hctx, i) {
		if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
			continue;

		clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
		blk_mq_run_hw_queue(hctx, async);
	}
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 58 93.55% 1 50.00%
christoph hellwig christoph hellwig 4 6.45% 1 50.00%
Total 62 100.00% 2 100.00%


EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);



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, run_work.work);

	__blk_mq_run_hw_queue(hctx);
}

Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 35 100.00% 1 100.00%
Total 35 100.00% 1 100.00%



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);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 33 70.21% 1 50.00%
christoph hellwig christoph hellwig 14 29.79% 1 50.00%
Total 47 100.00% 2 100.00%



void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
{
	if (unlikely(!blk_mq_hw_queue_mapped(hctx)))
		return;

	kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
			&hctx->delay_work, msecs_to_jiffies(msecs));
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 36 81.82% 2 50.00%
ming lei ming lei 7 15.91% 1 25.00%
jens axboe jens axboe 1 2.27% 1 25.00%
Total 44 100.00% 4 100.00%


EXPORT_SYMBOL(blk_mq_delay_queue);



static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
					    struct blk_mq_ctx *ctx,
					    struct request *rq,
					    bool at_head)
{
	trace_block_rq_insert(hctx->queue, rq);

	if (at_head)
		list_add(&rq->queuelist, &ctx->rq_list);
	else
		list_add_tail(&rq->queuelist, &ctx->rq_list);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 36 55.38% 2 50.00%
christoph hellwig christoph hellwig 21 32.31% 1 25.00%
ming lei ming lei 8 12.31% 1 25.00%
Total 65 100.00% 4 100.00%



static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
				    struct request *rq, bool at_head)
{
	struct blk_mq_ctx *ctx = rq->mq_ctx;

	__blk_mq_insert_req_list(hctx, ctx, rq, at_head);
	blk_mq_hctx_mark_pending(hctx, ctx);
}

Contributors
Person Tokens Prop Commits CommitProp
ming lei ming lei 38 82.61% 1 50.00%
jens axboe jens axboe 8 17.39% 1 50.00%
Total 46 100.00% 2 100.00%



void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue,
		bool async)
{
	struct request_queue *q = rq->q;
	struct blk_mq_hw_ctx *hctx;
	struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx;

	current_ctx = blk_mq_get_ctx(q);
	if (!cpu_online(ctx->cpu))
		rq->mq_ctx = ctx = current_ctx;

	hctx = q->mq_ops->map_queue(q, ctx->cpu);

	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);

	blk_mq_put_ctx(current_ctx);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 115 91.27% 2 50.00%
christoph hellwig christoph hellwig 11 8.73% 2 50.00%
Total 126 100.00% 4 100.00%



static void blk_mq_insert_requests(struct request_queue *q,
				     struct blk_mq_ctx *ctx,
				     struct list_head *list,
				     int depth,
				     bool from_schedule)

{
	struct blk_mq_hw_ctx *hctx;
	struct blk_mq_ctx *current_ctx;

	trace_block_unplug(q, depth, !from_schedule);

	current_ctx = blk_mq_get_ctx(q);

	if (!cpu_online(ctx->cpu))
		ctx = current_ctx;
	hctx = q->mq_ops->map_queue(q, ctx->cpu);

	/*
         * preemption doesn't flush plug list, so it's possible ctx->cpu is
         * offline now
         */
	spin_lock(&ctx->lock);
	while (!list_empty(list)) {
		struct request *rq;

		rq = list_first_entry(list, struct request, queuelist);
		list_del_init(&rq->queuelist);
		rq->mq_ctx = ctx;
		__blk_mq_insert_req_list(hctx, ctx, rq, false);
	}
	blk_mq_hctx_mark_pending(hctx, ctx);
	spin_unlock(&ctx->lock);

	blk_mq_run_hw_queue(hctx, from_schedule);
	blk_mq_put_ctx(current_ctx);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 159 92.98% 2 50.00%
ming lei ming lei 10 5.85% 1 25.00%
christoph hellwig christoph hellwig 2 1.17% 1 25.00%
Total 171 100.00% 4 100.00%



static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
{
	struct request *rqa = container_of(a, struct request, queuelist);
	struct request *rqb = container_of(b, struct request, queuelist);

	return !(rqa->mq_ctx < rqb->mq_ctx ||
		 (rqa->mq_ctx == rqb->mq_ctx &&
		  blk_rq_pos(rqa) < blk_rq_pos(rqb)));
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 82 100.00% 1 100.00%
Total 82 100.00% 1 100.00%



void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
{
	struct blk_mq_ctx *this_ctx;
	struct request_queue *this_q;
	struct request *rq;
	LIST_HEAD(list);
	LIST_HEAD(ctx_list);
	unsigned int depth;

	list_splice_init(&plug->mq_list, &list);

	list_sort(NULL, &list, plug_ctx_cmp);

	this_q = NULL;
	this_ctx = NULL;
	depth = 0;

	while (!list_empty(&list)) {
		rq = list_entry_rq(list.next);
		list_del_init(&rq->queuelist);
		BUG_ON(!rq->q);
		if (rq->mq_ctx != this_ctx) {
			if (this_ctx) {
				blk_mq_insert_requests(this_q, this_ctx,
							&ctx_list, depth,
							from_schedule);
			}

			this_ctx = rq->mq_ctx;
			this_q = rq->q;
			depth = 0;
		}

		depth++;
		list_add_tail(&rq->queuelist, &ctx_list);
	}

	/*
         * If 'this_ctx' is set, we know we have entries to complete
         * on 'ctx_list'. Do those.
         */
	if (this_ctx) {
		blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth,
				       from_schedule);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 192 100.00% 1 100.00%
Total 192 100.00% 1 100.00%



static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
{
	init_request_from_bio(rq, bio);

	blk_account_io_start(rq, 1);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%



static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx)
{
	return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
		!blk_queue_nomerges(hctx->queue);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 29 100.00% 1 100.00%
Total 29 100.00% 1 100.00%



static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
					 struct blk_mq_ctx *ctx,
					 struct request *rq, struct bio *bio)
{
	if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
		blk_mq_bio_to_request(rq, bio);
		spin_lock(&ctx->lock);
insert_rq:
		__blk_mq_insert_request(hctx, rq, false);
		spin_unlock(&ctx->lock);
		return false;
	} else {
		struct request_queue *q = hctx->queue;

		spin_lock(&ctx->lock);
		if (!blk_mq_attempt_merge(q, ctx, bio)) {
			blk_mq_bio_to_request(rq, bio);
			goto insert_rq;
		}

		spin_unlock(&ctx->lock);
		__blk_mq_free_request(hctx, ctx, rq);
		return true;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 138 95.83% 2 66.67%
ming lei ming lei 6 4.17% 1 33.33%
Total 144 100.00% 3 100.00%


struct blk_map_ctx {
	
struct blk_mq_hw_ctx *hctx;
	
struct blk_mq_ctx *ctx;
};



static struct request *blk_mq_map_request(struct request_queue *q,
					  struct bio *bio,
					  struct blk_map_ctx *data)
{
	struct blk_mq_hw_ctx *hctx;
	struct blk_mq_ctx *ctx;
	struct request *rq;
	int rw = bio_data_dir(bio);
	struct blk_mq_alloc_data alloc_data;

	blk_queue_enter_live(q);
	ctx = blk_mq_get_ctx(q);
	hctx = q->mq_ops->map_queue(q, ctx->cpu);

	if (rw_is_sync(bio->bi_rw))
		rw |= REQ_SYNC;

	trace_block_getrq(q, bio, rw);
	blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx);
	rq = __blk_mq_alloc_request(&alloc_data, rw);
	if (unlikely(!rq)) {
		__blk_mq_run_hw_queue(hctx);
		blk_mq_put_ctx(ctx);
		trace_block_sleeprq(q, bio, rw);

		ctx = blk_mq_get_ctx(q);
		hctx = q->mq_ops->map_queue(q, ctx->cpu);
		blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
		rq = __blk_mq_alloc_request(&alloc_data, rw);
		ctx = alloc_data.ctx;
		hctx = alloc_data.hctx;
	}

	hctx->queued++;
	data->hctx = hctx;
	data->ctx = ctx;
	return rq;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 161 70.00% 1 16.67%
lei ming lei ming 49 21.30% 1 16.67%
christoph hellwig christoph hellwig 19 8.26% 3 50.00%
dan williams dan williams 1 0.43% 1 16.67%
Total 230 100.00% 6 100.00%



static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
{
	int ret;
	struct request_queue *q = rq->q;
	struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q,
			rq->mq_ctx->cpu);
	struct blk_mq_queue_data bd = {
		.rq = rq,
		.list = NULL,
		.last = 1
	};
	blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);

	/*
         * For OK queue, we are done. For error, kill it. Any other
         * error (busy), just add it to our list as we previously
         * would have done
         */
	ret = q->mq_ops->queue_rq(hctx, &bd);
	if (ret == BLK_MQ_RQ_QUEUE_OK) {
		*cookie = new_cookie;
		return 0;
	}

	__blk_mq_requeue_request(rq);

	if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
		*cookie = BLK_QC_T_NONE;
		rq->errors = -EIO;
		blk_mq_end_request(rq, rq->errors);
		return 0;
	}

	return -1;
}

Contributors
Person Tokens Prop Commits CommitProp
shaohua li shaohua li 124 80.52% 1 50.00%
jens axboe jens axboe 30 19.48% 1 50.00%
Total 154 100.00% 2 100.00%

/*
 * Multiple hardware queue variant. This will not use per-process plugs,
 * but will attempt to bypass the hctx queueing if we can go straight to
 * hardware for SYNC IO.
 */


static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
{
	const int is_sync = rw_is_sync(bio->bi_rw);
	const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
	struct blk_map_ctx data;
	struct request *rq;
	unsigned int request_count = 0;
	struct blk_plug *plug;
	struct request *same_queue_rq = NULL;
	blk_qc_t cookie;

	blk_queue_bounce(q, &bio);

	if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
		bio_io_error(bio);
		return BLK_QC_T_NONE;
	}

	blk_queue_split(q, &bio, q->bio_split);

	if (!is_flush_fua && !blk_queue_nomerges(q) &&
	    blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
		return BLK_QC_T_NONE;

	rq = blk_mq_map_request(q, bio, &data);
	if (unlikely(!rq))
		return BLK_QC_T_NONE;

	cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);

	if (unlikely(is_flush_fua)) {
		blk_mq_bio_to_request(rq, bio);
		blk_insert_flush(rq);
		goto run_queue;
	}

	plug = current->plug;
	/*
         * If the driver supports defer issued based on 'last', then
         * queue it up like normal since we can potentially save some
         * CPU this way.
         */
	if (((plug && !blk_queue_nomerges(q)) || is_sync) &&
	    !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
		struct request *old_rq = NULL;

		blk_mq_bio_to_request(rq, bio);

		/*
                 * We do limited pluging. If the bio can be merged, do that.
                 * Otherwise the existing request in the plug list will be
                 * issued. So the plug list will have one request at most
                 */
		if (plug) {
			/*
                         * The plug list might get flushed before this. If that
                         * happens, same_queue_rq is invalid and plug list is
                         * empty
                         */
			if (same_queue_rq && !list_empty(&plug->mq_list)) {
				old_rq = same_queue_rq;
				list_del_init(&old_rq->queuelist);
			}
			list_add_tail(&rq->queuelist, &plug->mq_list);
		} else /* is_sync */
			old_rq = rq;
		blk_mq_put_ctx(data.ctx);
		if (!old_rq)
			goto done;
		if (!blk_mq_direct_issue_request(old_rq, &cookie))
			goto done;
		blk_mq_insert_request(old_rq, false, true, true);
		goto done;
	}

	if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
		/*
                 * For a SYNC request, send it to the hardware immediately. For
                 * an ASYNC request, just ensure that we run it later on. The
                 * latter allows for merging opportunities and more efficient
                 * dispatching.
                 */
run_queue:
		blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
	}
	blk_mq_put_ctx(data.ctx);
done:
	return cookie;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 268 67.68% 7 53.85%
shaohua li shaohua li 114 28.79% 3 23.08%
kent overstreet kent overstreet 12 3.03% 1 7.69%
christoph hellwig christoph hellwig 1 0.25% 1 7.69%
omar sandoval omar sandoval 1 0.25% 1 7.69%
Total 396 100.00% 13 100.00%

/*
 * Single hardware queue variant. This will attempt to use any per-process
 * plug for merging and IO deferral.
 */


static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
{
	const int is_sync = rw_is_sync(bio->bi_rw);
	const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
	struct blk_plug *plug;
	unsigned int request_count = 0;
	struct blk_map_ctx data;
	struct request *rq;
	blk_qc_t cookie;

	blk_queue_bounce(q, &bio);

	if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
		bio_io_error(bio);
		return BLK_QC_T_NONE;
	}

	blk_queue_split(q, &bio, q->bio_split);

	if (!is_flush_fua && !blk_queue_nomerges(q)) {
		if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
			return BLK_QC_T_NONE;
	} else
		request_count = blk_plug_queued_count(q);

	rq = blk_mq_map_request(q, bio, &data);
	if (unlikely(!rq))
		return BLK_QC_T_NONE;

	cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);

	if (unlikely(is_flush_fua)) {
		blk_mq_bio_to_request(rq, bio);
		blk_insert_flush(rq);
		goto run_queue;
	}

	/*
         * A task plug currently exists. Since this is completely lockless,
         * utilize that to temporarily store requests until the task is
         * either done or scheduled away.
         */
	plug = current->plug;
	if (plug) {
		blk_mq_bio_to_request(rq, bio);
		if (!request_count)
			trace_block_plug(q);

		blk_mq_put_ctx(data.ctx);

		if (request_count >= BLK_MAX_REQUEST_COUNT) {
			blk_flush_plug_list(plug, false);
			trace_block_plug(q);
		}

		list_add_tail(&rq->queuelist, &plug->mq_list);
		return cookie;
	}

	if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
		/*
                 * For a SYNC request, send it to the hardware immediately. For
                 * an ASYNC request, just ensure that we run it later on. The
                 * latter allows for merging opportunities and more efficient
                 * dispatching.
                 */
run_queue:
		blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
	}

	blk_mq_put_ctx(data.ctx);
	return cookie;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 262 80.86% 8 50.00%
nicholas bellinger nicholas bellinger 18 5.56% 1 6.25%
omar sandoval omar sandoval 13 4.01% 1 6.25%
kent overstreet kent overstreet 12 3.70% 1 6.25%
jeff moyer jeff moyer 9 2.78% 1 6.25%
robert elliott robert elliott 5 1.54% 1 6.25%
shaohua li shaohua li 2 0.62% 1 6.25%
ming lei ming lei 2 0.62% 1 6.25%
christoph hellwig christoph hellwig 1 0.31% 1 6.25%
Total 324 100.00% 16 100.00%

/*
 * Default mapping to a software queue, since we use one per CPU.
 */


struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
{
	return q->queue_hw_ctx[q->mq_map[cpu]];
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 29 100.00% 1 100.00%
Total 29 100.00% 1 100.00%


EXPORT_SYMBOL(blk_mq_map_queue);



static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
		struct blk_mq_tags *tags, unsigned int hctx_idx)
{
	struct page *page;

	if (tags->rqs && set->ops->exit_request) {
		int i;

		for (i = 0; i < tags->nr_tags; i++) {
			if (!tags->rqs[i])
				continue;
			set->ops->exit_request(set->driver_data, tags->rqs[i],
						hctx_idx, i);
			tags->rqs[i] = NULL;
		}
	}

	while (!list_empty(&tags->page_list)) {
		page = list_first_entry(&tags->page_list, struct page, lru);
		list_del_init(&page->lru);
		/*
                 * Remove kmemleak object previously allocated in
                 * blk_mq_init_rq_map().
                 */
		kmemleak_free(page_address(page));
		__free_pages(page, page->private);
	}

	kfree(tags->rqs);

	blk_mq_free_tags(tags);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 106 63.47% 3 42.86%
christoph hellwig christoph hellwig 50 29.94% 2 28.57%
catalin marinas catalin marinas 9 5.39% 1 14.29%
dave hansen dave hansen 2 1.20% 1 14.29%
Total 167 100.00% 7 100.00%



static size_t order_to_size(unsigned int order)
{
	return (size_t)PAGE_SIZE << order;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 14 77.78% 1 50.00%
lei ming lei ming 4 22.22% 1 50.00%
Total 18 100.00% 2 100.00%



static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
		unsigned int hctx_idx)
{
	struct blk_mq_tags *tags;
	unsigned int i, j, entries_per_page, max_order = 4;
	size_t rq_size, left;

	tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags,
				set->numa_node,
				BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
	if (!tags)
		return NULL;

	INIT_LIST_HEAD(&tags->page_list);

	tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *),
				 GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
				 set->numa_node);
	if (!tags->rqs) {
		blk_mq_free_tags(tags);
		return NULL;
	}

	/*
         * rq_size is the size of the request plus driver payload, rounded
         * to the cacheline size
         */
	rq_size = round_up(sizeof(struct request) + set->cmd_size,
				cache_line_size());
	left = rq_size * set->queue_depth;

	for (i = 0; i < set->queue_depth; ) {
		int this_order = max_order;
		struct page *page;
		int to_do;
		void *p;

		while (this_order && left < order_to_size(this_order - 1))
			this_order--;

		do {
			page = alloc_pages_node(set->numa_node,
				GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO,
				this_order);
			if (page)
				break;
			if (!this_order--)
				break;
			if (order_to_size(this_order) < rq_size)
				break;
		} while (1);

		if (!page)
			goto fail;

		page->private = this_order;
		list_add_tail(&page->lru, &tags->page_list);

		p = page_address(page);
		/*
                 * Allow kmemleak to scan these pages as they contain pointers
                 * to additional allocations like via ops->init_request().
                 */
		kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL);
		entries_per_page = order_to_size(this_order) / rq_size;
		to_do = min(entries_per_page, set->queue_depth - i);
		left -= to_do * rq_size;
		for (j = 0; j < to_do; j++) {
			tags->rqs[i] = p;
			if (set->ops->init_request) {
				if (set->ops->init_request(set->driver_data,
						tags->rqs[i], hctx_idx, i,
						set->numa_node)) {
					tags->rqs[i] = NULL;
					goto fail;
				}
			}

			p += rq_size;
			i++;
		}
	}
	return tags;

fail:
	blk_mq_free_rq_map(set, tags, hctx_idx);
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 279 65.65% 2 22.22%
christoph hellwig christoph hellwig 119 28.00% 2 22.22%
catalin marinas catalin marinas 15 3.53% 1 11.11%
shaohua li shaohua li 7 1.65% 1 11.11%
linus torvalds linus torvalds 2 0.47% 1 11.11%
bartlomiej zolnierkiewicz bartlomiej zolnierkiewicz 2 0.47% 1 11.11%
dave hansen dave hansen 1 0.24% 1 11.11%
Total 425 100.00% 9 100.00%



static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap)
{
	kfree(bitmap->map);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 18 100.00% 1 100.00%
Total 18 100.00% 1 100.00%



static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node)
{
	unsigned int bpw = 8, total, num_maps, i;

	bitmap->bits_per_word = bpw;

	num_maps = ALIGN(nr_cpu_ids, bpw) / bpw;
	bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap),
					GFP_KERNEL, node);
	if (!bitmap->map)
		return -ENOMEM;

	total = nr_cpu_ids;
	for (i = 0; i < num_maps; i++) {
		bitmap->map[i].depth = min(total, bitmap->bits_per_word);
		total -= bitmap->map[i].depth;
	}

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 124 100.00% 1 100.00%
Total 124 100.00% 1 100.00%



static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu)
{
	struct request_queue *q = hctx->queue;
	struct blk_mq_ctx *ctx;
	LIST_HEAD(tmp);

	/*
         * Move ctx entries to new CPU, if this one is going away.
         */
	ctx = __blk_mq_get_ctx(q, cpu);

	spin_lock(&ctx->lock);
	if (!list_empty(&ctx->rq_list)) {
		list_splice_init(&ctx->rq_list, &tmp);
		blk_mq_hctx_clear_pending(hctx, ctx);
	}
	spin_unlock(&ctx->lock);

	if (list_empty(&tmp))
		return NOTIFY_OK;

	ctx = blk_mq_get_ctx(q);
	spin_lock(&ctx->lock);

	while (!list_empty(&tmp)) {
		struct request *rq;

		rq = list_first_entry(&tmp, struct request, queuelist);
		rq->mq_ctx = ctx;
		list_move_tail(&rq->queuelist, &ctx->rq_list);
	}

	hctx = q->mq_ops->map_queue(q, ctx->cpu);
	blk_mq_hctx_mark_pending(hctx, ctx);

	spin_unlock(&ctx->lock);

	blk_mq_run_hw_queue(hctx, true);
	blk_mq_put_ctx(ctx);
	return NOTIFY_OK;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 209 100.00% 2 100.00%
Total 209 100.00% 2 100.00%



static int blk_mq_hctx_notify(void *data, unsigned long action,
			      unsigned int cpu)
{
	struct blk_mq_hw_ctx *hctx = data;

	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
		return blk_mq_hctx_cpu_offline(hctx, cpu);

	/*
         * In case of CPU online, tags may be reallocated
         * in blk_mq_map_swqueue() after mapping is updated.
         */

	return NOTIFY_OK;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 46 97.87% 1 50.00%
ming lei ming lei 1 2.13% 1 50.00%
Total 47 100.00% 2 100.00%

/* hctx->ctxs will be freed in queue's release handler */


static void blk_mq_exit_hctx(struct request_queue *q,
		struct blk_mq_tag_set *set,
		struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
{
	unsigned flush_start_tag = set->queue_depth;

	blk_mq_tag_idle(hctx);

	if (set->ops->exit_request)
		set->ops->exit_request(set->driver_data,
				       hctx->fq->flush_rq, hctx_idx,
				       flush_start_tag + hctx_idx);

	if (set->ops->exit_hctx)
		set->ops->exit_hctx(hctx, hctx_idx);

	blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
	blk_free_flush_queue(hctx->fq);
	blk_mq_free_bitmap(&hctx->ctx_map);
}

Contributors
Person Tokens Prop Commits CommitProp
lei ming lei ming 65 59.09% 1 25.00%
ming lei ming lei 38 34.55% 2 50.00%
jens axboe jens axboe 7 6.36% 1 25.00%
Total 110 100.00% 4 100.00%



static void blk_mq_exit_hw_queues(struct request_queue *q,
		struct blk_mq_tag_set *set, int nr_queue)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned int i;

	queue_for_each_hw_ctx(q, hctx, i) {
		if (i == nr_queue)
			break;
		blk_mq_exit_hctx(q, set, hctx, i);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
lei ming lei ming 38 67.86% 1 50.00%
ming lei ming lei 18 32.14% 1 50.00%
Total 56 100.00% 2 100.00%



static void blk_mq_free_hw_queues(struct request_queue *q,
		struct blk_mq_tag_set *set)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned int i;

	queue_for_each_hw_ctx(q, hctx, i)
		free_cpumask_var(hctx->cpumask);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 28 70.00% 2 50.00%
ming lei ming lei 10 25.00% 1 25.00%
christoph hellwig christoph hellwig 2 5.00% 1 25.00%
Total 40 100.00% 4 100.00%



static int blk_mq_init_hctx(struct request_queue *q,
		struct blk_mq_tag_set *set,
		struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
{
	int node;
	unsigned flush_start_tag = set->queue_depth;

	node = hctx->numa_node;
	if (node == NUMA_NO_NODE)
		node = hctx->numa_node = set->numa_node;

	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;
	hctx->queue_num = hctx_idx;
	hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;

	blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
					blk_mq_hctx_notify, hctx);
	blk_mq_register_cpu_notifier(&hctx->cpu_notifier);

	hctx->tags = set->tags[hctx_idx];

	/*
         * Allocate space for all possible cpus to avoid allocation at
         * runtime
         */
	hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
					GFP_KERNEL, node);
	if (!hctx->ctxs)
		goto unregister_cpu_notifier;

	if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
		goto free_ctxs;

	hctx->nr_ctx = 0;

	if (set->ops->init_hctx &&
	    set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
		goto free_bitmap;

	hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
	if (!hctx->fq)
		goto exit_hctx;

	if (set->ops->init_request &&
	    set->ops->init_request(set->driver_data,
				   hctx->fq->flush_rq, hctx_idx,
				   flush_start_tag + hctx_idx, node))
		goto free_fq;

	return 0;

 free_fq:
	kfree(hctx->fq);
 exit_hctx:
	if (set->ops->exit_hctx)
		set->ops->exit_hctx(hctx, hctx_idx);
 free_bitmap:
	blk_mq_free_bitmap(&hctx->ctx_map);
 free_ctxs:
	kfree(hctx->ctxs);
 unregister_cpu_notifier:
	blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);

	return -1;
}

Contributors
Person Tokens Prop Commits CommitProp
ming lei ming lei 175 49.72% 2 28.57%
jens axboe jens axboe 147 41.76% 2 28.57%
christoph hellwig christoph hellwig 27 7.67% 2 28.57%
jeff moyer jeff moyer 3 0.85% 1 14.29%
Total 352 100.00% 7 100.00%



static void blk_mq_init_cpu_queues(struct request_queue *q,
				   unsigned int nr_hw_queues)
{
	unsigned int i;

	for_each_possible_cpu(i) {
		struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
		struct blk_mq_hw_ctx *hctx;

		memset(__ctx, 0, sizeof(*__ctx));
		__ctx->cpu = i;
		spin_lock_init(&__ctx->lock);
		INIT_LIST_HEAD(&__ctx->rq_list);
		__ctx->queue = q;

		/* If the cpu isn't online, the cpu is mapped to first hctx */
		if (!cpu_online(i))
			continue;

		hctx = q->mq_ops->map_queue(q, i);

		/*
                 * Set local node, IFF we have more than one hw queue. If
                 * not, we remain on the home node of the device
                 */
		if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
			hctx->numa_node = local_memory_node(cpu_to_node(i));
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 130 97.74% 2 66.67%
raghavendra k t* (same as raghavendra koushik) raghavendra k t* (same as raghavendra koushik) 3 2.26% 1 33.33%
Total 133 100.00% 3 100.00%



static void blk_mq_map_swqueue(struct request_queue *q,
			       const struct cpumask *online_mask)
{
	unsigned int i;
	struct blk_mq_hw_ctx *hctx;
	struct blk_mq_ctx *ctx;
	struct blk_mq_tag_set *set = q->tag_set;

	/*
         * Avoid others reading imcomplete hctx->cpumask through sysfs
         */
	mutex_lock(&q->sysfs_lock);

	queue_for_each_hw_ctx(q, hctx, i) {
		cpumask_clear(hctx->cpumask);
		hctx->nr_ctx = 0;
	}

	/*
         * Map software to hardware queues
         */
	for_each_possible_cpu(i) {
		/* If the cpu isn't online, the cpu is mapped to first hctx */
		if (!cpumask_test_cpu(i, online_mask))
			continue;

		ctx = per_cpu_ptr(q->queue_ctx, i);
		hctx = q->mq_ops->map_queue(q, i);

		cpumask_set_cpu(i, hctx->cpumask);
		ctx->index_hw = hctx->nr_ctx;
		hctx->ctxs[hctx->nr_ctx++] = ctx;
	}

	mutex_unlock(&q->sysfs_lock);

	queue_for_each_hw_ctx(q, hctx, i) {
		struct blk_mq_ctxmap *map = &hctx->ctx_map;

		/*
                 * If no software queues are mapped to this hardware queue,
                 * disable it and free the request entries.
                 */
		if (!hctx->nr_ctx) {
			if (set->tags[i]) {
				blk_mq_free_rq_map(set, set->tags[i], i);
				set->tags[i] = NULL;
			}
			hctx->tags = NULL;
			continue;
		}

		/* unmapped hw queue can be remapped after CPU topo changed */
		if (!set->tags[i])
			set->tags[i] = blk_mq_init_rq_map(set, i);
		hctx->tags = set->tags[i];
		WARN_ON(!hctx->tags);

		cpumask_copy(hctx->tags->cpumask, hctx->cpumask);
		/*
                 * Set the map size to the number of mapped software queues.
                 * This is more accurate and more efficient than looping
                 * over all possibly mapped software queues.
                 */
		map->size = DIV_ROUND_UP(hctx->nr_ctx, map->bits_per_word);

		/*
                 * Initialize batch roundrobin counts
                 */
		hctx->next_cpu = cpumask_first(hctx->cpumask);
		hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 188 59.87% 6 50.00%
ming lei ming lei 54 17.20% 1 8.33%
akinobu mita akinobu mita 26 8.28% 2 16.67%
chong yuan chong yuan 21 6.69% 1 8.33%
raghavendra k t* (same as raghavendra koushik) raghavendra k t* (same as raghavendra koushik) 13 4.14% 1 8.33%
thomas gleixner thomas gleixner 12 3.82% 1 8.33%
Total 314 100.00% 12 100.00%



static void queue_set_hctx_shared(struct request_queue *q, bool shared)
{
	struct blk_mq_hw_ctx *hctx;
	int i;

	queue_for_each_hw_ctx(q, hctx, i) {
		if (shared)
			hctx->flags |= BLK_MQ_F_TAG_SHARED;
		else
			hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 43 86.00% 1 50.00%
jeff moyer jeff moyer 7 14.00% 1 50.00%
Total 50 100.00% 2 100.00%



static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
{
	struct request_queue *q;

	list_for_each_entry(q, &set->tag_list, tag_set_list) {
		blk_mq_freeze_queue(q);
		queue_set_hctx_shared(q, shared);
		blk_mq_unfreeze_queue(q);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
jeff moyer jeff moyer 39 84.78% 1 50.00%
jens axboe jens axboe 7 15.22% 1 50.00%
Total 46 100.00% 2 100.00%



static void blk_mq_del_queue_tag_set(struct request_queue *q)
{
	struct blk_mq_tag_set *set = q->tag_set;

	mutex_lock(&set->tag_list_lock);
	list_del_init(&q->tag_set_list);
	if (list_is_singular(&set->tag_list)) {
		/* just transitioned to unshared */
		set->flags &= ~BLK_MQ_F_TAG_SHARED;
		/* update existing queue */
		blk_mq_update_tag_set_depth(set, false);
	}
	mutex_unlock(&set->tag_list_lock);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 49 68.06% 1 50.00%
jeff moyer jeff moyer 23 31.94% 1 50.00%
Total 72 100.00% 2 100.00%



static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
				     struct request_queue *q)
{
	q->tag_set = set;

	mutex_lock(&set->tag_list_lock);

	/* Check to see if we're transitioning to shared (from 1 to 2 queues). */
	if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) {
		set->flags |= BLK_MQ_F_TAG_SHARED;
		/* update existing queue */
		blk_mq_update_tag_set_depth(set, true);
	}
	if (set->flags & BLK_MQ_F_TAG_SHARED)
		queue_set_hctx_shared(q, true);
	list_add_tail(&q->tag_set_list, &set->tag_list);

	mutex_unlock(&set->tag_list_lock);
}

Contributors
Person Tokens Prop Commits CommitProp
jeff moyer jeff moyer 52 50.49% 1 50.00%
jens axboe jens axboe 51 49.51% 1 50.00%
Total 103 100.00% 2 100.00%

/*
 * It is the actual release handler for mq, but we do it from
 * request queue's release handler for avoiding use-after-free
 * and headache because q->mq_kobj shouldn't have been introduced,
 * but we can't group ctx/kctx kobj without it.
 */


void blk_mq_release(struct request_queue *q)
{
	struct blk_mq_hw_ctx *hctx;
	unsigned int i;

	/* hctx kobj stays in hctx */
	queue_for_each_hw_ctx(q, hctx, i) {
		if (!hctx)
			continue;
		kfree(hctx->ctxs);
		kfree(hctx);
	}

	kfree(q->mq_map);
	q->mq_map = NULL;

	kfree(q->queue_hw_ctx);

	/* ctx kobj stays in queue_ctx */
	free_percpu(q->queue_ctx);
}

Contributors
Person Tokens Prop Commits CommitProp
ming lei ming lei 48 63.16% 1 33.33%
lei ming lei ming 15 19.74% 1 33.33%
akinobu mita akinobu mita 13 17.11% 1 33.33%
Total 76 100.00% 3 100.00%



struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
{
	struct request_queue *uninit_q, *q;

	uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
	if (!uninit_q)
		return ERR_PTR(-ENOMEM);

	q = blk_mq_init_allocated_queue(set, uninit_q);
	if (IS_ERR(q))
		blk_cleanup_queue(uninit_q);

	return q;
}
Contributors
Person Tokens Prop Commits CommitProp
mike snitzer mike snitzer 55 82.09% 1 33.33%
jens axboe jens axboe 10 14.93% 1 33.33%
christoph hellwig christoph hellwig 2 2.99% 1 33.33%
Total 67 100.00% 3 100.00%


EXPORT_SYMBOL(blk_mq_init_queue);



static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
						struct request_queue *q)
{
	int i, j;
	struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;

	blk_mq_sysfs_unregister(q);
	for (i = 0; i < set->nr_hw_queues; i++) {
		int node;

		if (hctxs[i])
			continue;

		node = blk_mq_hw_queue_to_node(q->mq_map, i);
		hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx),
					GFP_KERNEL, node);
		if (!hctxs[i])
			break;

		if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
						node)) {
			kfree(hctxs[i]);
			hctxs[i] = NULL;
			break;
		}

		atomic_set(&hctxs[i]->nr_active, 0);
		hctxs[i]->numa_node = node;
		hctxs[i]->queue_num = i;

		if (blk_mq_init_hctx(q, set, hctxs[i], i)) {
			free_cpumask_var(hctxs[i]->cpumask);
			kfree(hctxs[i]);
			hctxs[i] = NULL;
			break;
		}
		blk_mq_hctx_kobj_init(hctxs[i]);
	}
	for (j = i; j < q->nr_hw_queues; j++) {
		struct blk_mq_hw_ctx *hctx = hctxs[j];

		if (hctx) {
			if (hctx->tags) {
				blk_mq_free_rq_map(set, hctx->tags, j);
				set->tags[j] = NULL;
			}
			blk_mq_exit_hctx(q, set, hctx, j);
			free_cpumask_var(hctx->cpumask);
			kobject_put(&hctx->kobj);
			kfree(hctx->ctxs);
			kfree(hctx);
			hctxs[j] = NULL;

		}
	}
	q->nr_hw_queues = i;
	blk_mq_sysfs_register(q);
}

Contributors
Person Tokens Prop Commits CommitProp
keith busch keith busch 201 59.47% 1 10.00%
jens axboe jens axboe 115 34.02% 5 50.00%
mike snitzer mike snitzer 12 3.55% 1 10.00%
christoph hellwig christoph hellwig 9 2.66% 2 20.00%
fang wei fang wei 1 0.30% 1 10.00%
Total 338 100.00% 10 100.00%



struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
						  struct request_queue *q)
{
	/* mark the queue as mq asap */
	q->mq_ops = set->ops;

	q->queue_ctx = alloc_percpu(struct blk_mq_ctx);
	if (!q->queue_ctx)
		goto err_exit;

	q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)),
						GFP_KERNEL, set->numa_node);
	if (!q->queue_hw_ctx)
		goto err_percpu;

	q->mq_map = blk_mq_make_queue_map(set);
	if (!q->mq_map)
		goto err_map;

	blk_mq_realloc_hw_ctxs(set, q);
	if (!q->nr_hw_queues)
		goto err_hctxs;

	INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
	blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);

	q->nr_queues = nr_cpu_ids;

	q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;

	if (!(set->flags & BLK_MQ_F_SG_MERGE))
		q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE;

	q->sg_reserved_size = INT_MAX;

	INIT_WORK(&q->requeue_work, blk_mq_requeue_work);
	INIT_LIST_HEAD(&q->requeue_list);
	spin_lock_init(&q->requeue_lock);

	if (q->nr_hw_queues > 1)
		blk_queue_make_request(q, blk_mq_make_request);
	else
		blk_queue_make_request(q, blk_sq_make_request);

	/*
         * Do this after blk_queue_make_request() overrides it...
         */
	q->nr_requests = set->queue_depth;

	if (set->ops->complete)
		blk_queue_softirq_done(q, set->ops->complete);

	blk_mq_init_cpu_queues(q, set->nr_hw_queues);

	get_online_cpus();
	mutex_lock(&all_q_mutex);

	list_add_tail(&q->all_q_node, &all_q_list);
	blk_mq_add_queue_tag_set(set, q);
	blk_mq_map_swqueue(q, cpu_online_mask);

	mutex_unlock(&all_q_mutex);
	put_online_cpus();

	return q;

err_hctxs:
	kfree(q->mq_map);
err_map:
	kfree(q->queue_hw_ctx);
err_percpu:
	free_percpu(q->queue_ctx);
err_exit:
	q->mq_ops = NULL;
	return ERR_PTR(-ENOMEM);
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 161 45.35% 9 42.86%
keith busch keith busch 97 27.32% 1 4.76%
christoph hellwig christoph hellwig 56 15.77% 5 23.81%
akinobu mita akinobu mita 14 3.94% 2 9.52%
lin ming lin ming 11 3.10% 1 4.76%
fang wei fang wei 8 2.25% 1 4.76%
lei ming lei ming 5 1.41% 1 4.76%
ming lei ming lei 3 0.85% 1 4.76%
Total 355 100.00% 21 100.00%


EXPORT_SYMBOL(blk_mq_init_allocated_queue);



void blk_mq_free_queue(struct request_queue *q)
{
	struct blk_mq_tag_set	*set = q->tag_set;

	mutex_lock(&all_q_mutex);
	list_del_init(&q->all_q_node);
	mutex_unlock(&all_q_mutex);

	blk_mq_del_queue_tag_set(q);

	blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
	blk_mq_free_hw_queues(q, set);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 29 46.77% 3 60.00%
akinobu mita akinobu mita 20 32.26% 1 20.00%
lei ming lei ming 13 20.97% 1 20.00%
Total 62 100.00% 5 100.00%

/* Basically redo blk_mq_init_queue with queue frozen */


static void blk_mq_queue_reinit(struct request_queue *q,
				const struct cpumask *online_mask)
{
	WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));

	blk_mq_sysfs_unregister(q);

	blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues, online_mask);

	/*
         * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
         * we should change hctx numa_node according to new topology (this
         * involves free and re-allocate memory, worthy doing?)
         */

	blk_mq_map_swqueue(q, online_mask);

	blk_mq_sysfs_register(q);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 42 70.00% 2 40.00%
akinobu mita akinobu mita 10 16.67% 1 20.00%
christoph hellwig christoph hellwig 4 6.67% 1 20.00%
tejun heo tejun heo 4 6.67% 1 20.00%
Total 60 100.00% 5 100.00%



static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
				      unsigned long action, void *hcpu)
{
	struct request_queue *q;
	int cpu = (unsigned long)hcpu;
	/*
         * New online cpumask which is going to be set in this hotplug event.
         * Declare this cpumasks as global as cpu-hotplug operation is invoked
         * one-by-one and dynamically allocating this could result in a failure.
         */
	static struct cpumask online_new;

	/*
         * Before hotadded cpu starts handling requests, new mappings must
         * be established.  Otherwise, these requests in hw queue might
         * never be dispatched.
         *
         * For example, there is a single hw queue (hctx) and two CPU queues
         * (ctx0 for CPU0, and ctx1 for CPU1).
         *
         * Now CPU1 is just onlined and a request is inserted into
         * ctx1->rq_list and set bit0 in pending bitmap as ctx1->index_hw is
         * still zero.
         *
         * And then while running hw queue, flush_busy_ctxs() finds bit0 is
         * set in pending bitmap and tries to retrieve requests in
         * hctx->ctxs[0]->rq_list.  But htx->ctxs[0] is a pointer to ctx0,
         * so the request in ctx1->rq_list is ignored.
         */
	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_DEAD:
	case CPU_UP_CANCELED:
		cpumask_copy(&online_new, cpu_online_mask);
		break;
	case CPU_UP_PREPARE:
		cpumask_copy(&online_new, cpu_online_mask);
		cpumask_set_cpu(cpu, &online_new);
		break;
	default:
		return NOTIFY_OK;
	}

	mutex_lock(&all_q_mutex);

	/*
         * We need to freeze and reinit all existing queues.  Freezing
         * involves synchronous wait for an RCU grace period and doing it
         * one by one may take a long time.  Start freezing all queues in
         * one swoop and then wait for the completions so that freezing can
         * take place in parallel.
         */
	list_for_each_entry(q, &all_q_list, all_q_node)
		blk_mq_freeze_queue_start(q);
	list_for_each_entry(q, &all_q_list, all_q_node) {
		blk_mq_freeze_queue_wait(q);

		/*
                 * timeout handler can't touch hw queue during the
                 * reinitialization
                 */
		del_timer_sync(&q->timeout);
	}

	list_for_each_entry(q, &all_q_list, all_q_node)
		blk_mq_queue_reinit(q, &online_new);

	list_for_each_entry(q, &all_q_list, all_q_node)
		blk_mq_unfreeze_queue(q);

	mutex_unlock(&all_q_mutex);
	return NOTIFY_OK;
}

Contributors
Person Tokens Prop Commits CommitProp
akinobu mita akinobu mita 61 35.88% 1 25.00%
jens axboe jens axboe 58 34.12% 1 25.00%
tejun heo tejun heo 40 23.53% 1 25.00%
ming lei ming lei 11 6.47% 1 25.00%
Total 170 100.00% 4 100.00%



static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
{
	int i;

	for (i = 0; i < set->nr_hw_queues; i++) {
		set->tags[i] = blk_mq_init_rq_map(set, i);
		if (!set->tags[i])
			goto out_unwind;
	}

	return 0;

out_unwind:
	while (--i >= 0)
		blk_mq_free_rq_map(set, set->tags[i], i);

	return -ENOMEM;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 88 100.00% 1 100.00%
Total 88 100.00% 1 100.00%

/*
 * Allocate the request maps associated with this tag_set. Note that this
 * may reduce the depth asked for, if memory is tight. set->queue_depth
 * will be updated to reflect the allocated depth.
 */


static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
{
	unsigned int depth;
	int err;

	depth = set->queue_depth;
	do {
		err = __blk_mq_alloc_rq_maps(set);
		if (!err)
			break;

		set->queue_depth >>= 1;
		if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
			err = -ENOMEM;
			break;
		}
	} while (set->queue_depth);

	if (!set->queue_depth || err) {
		pr_err("blk-mq: failed to allocate request map\n");
		return -ENOMEM;
	}

	if (depth != set->queue_depth)
		pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
						depth, set->queue_depth);

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 115 100.00% 1 100.00%
Total 115 100.00% 1 100.00%



struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags)
{
	return tags->cpumask;
}
Contributors
Person Tokens Prop Commits CommitProp
keith busch keith busch 17 100.00% 1 100.00%
Total 17 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(blk_mq_tags_cpumask);

/*
 * Alloc a tag set to be associated with one or more request queues.
 * May fail with EINVAL for various error conditions. May adjust the
 * requested depth down, if if it too large. In that case, the set
 * value will be stored in set->queue_depth.
 */


int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
{
	BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);

	if (!set->nr_hw_queues)
		return -EINVAL;
	if (!set->queue_depth)
		return -EINVAL;
	if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
		return -EINVAL;

	if (!set->ops->queue_rq || !set->ops->map_queue)
		return -EINVAL;

	if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
		pr_info("blk-mq: reduced tag depth to %u\n",
			BLK_MQ_MAX_DEPTH);
		set->queue_depth = BLK_MQ_MAX_DEPTH;
	}

	/*
         * If a crashdump is active, then we are potentially in a very
         * memory constrained environment. Limit us to 1 queue and
         * 64 tags to prevent using too much memory.
         */
	if (is_kdump_kernel()) {
		set->nr_hw_queues = 1;
		set->queue_depth = min(64U, set->queue_depth);
	}
	/*
         * There is no use for more h/w queues than cpus.
         */
	if (set->nr_hw_queues > nr_cpu_ids)
		set->nr_hw_queues = nr_cpu_ids;

	set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *),
				 GFP_KERNEL, set->numa_node);
	if (!set->tags)
		return -ENOMEM;

	if (blk_mq_alloc_rq_maps(set))
		goto enomem;

	mutex_init(&set->tag_list_lock);
	INIT_LIST_HEAD(&set->tag_list);

	return 0;
enomem:
	kfree(set->tags);
	set->tags = NULL;
	return -ENOMEM;
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 114 51.12% 1 11.11%
jens axboe jens axboe 48 21.52% 3 33.33%
shaohua li shaohua li 27 12.11% 1 11.11%
keith busch keith busch 17 7.62% 1 11.11%
bart van assche bart van assche 9 4.04% 1 11.11%
robert elliott robert elliott 7 3.14% 1 11.11%
lei ming lei ming 1 0.45% 1 11.11%
Total 223 100.00% 9 100.00%


EXPORT_SYMBOL(blk_mq_alloc_tag_set);



void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
{
	int i;

	for (i = 0; i < nr_cpu_ids; i++) {
		if (set->tags[i])
			blk_mq_free_rq_map(set, set->tags[i], i);
	}

	kfree(set->tags);
	set->tags = NULL;
}
Contributors
Person Tokens Prop Commits CommitProp
christoph hellwig christoph hellwig 39 60.94% 1 20.00%
jens axboe jens axboe 11 17.19% 1 20.00%
lei ming lei ming 7 10.94% 1 20.00%
robert elliott robert elliott 6 9.38% 1 20.00%
keith busch keith busch 1 1.56% 1 20.00%
Total 64 100.00% 5 100.00%


EXPORT_SYMBOL(blk_mq_free_tag_set);



int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
{
	struct blk_mq_tag_set *set = q->tag_set;
	struct blk_mq_hw_ctx *hctx;
	int i, ret;

	if (!set || nr > set->queue_depth)
		return -EINVAL;

	ret = 0;
	queue_for_each_hw_ctx(q, hctx, i) {
		if (!hctx->tags)
			continue;
		ret = blk_mq_tag_update_depth(hctx->tags, nr);
		if (ret)
			break;
	}

	if (!ret)
		q->nr_requests = nr;

	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 92 92.00% 1 50.00%
keith busch keith busch 8 8.00% 1 50.00%
Total 100 100.00% 2 100.00%



void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
{
	struct request_queue *q;

	if (nr_hw_queues > nr_cpu_ids)
		nr_hw_queues = nr_cpu_ids;
	if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)
		return;

	list_for_each_entry(q, &set->tag_list, tag_set_list)
		blk_mq_freeze_queue(q);

	set->nr_hw_queues = nr_hw_queues;
	list_for_each_entry(q, &set->tag_list, tag_set_list) {
		blk_mq_realloc_hw_ctxs(set, q);

		if (q->nr_hw_queues > 1)
			blk_queue_make_request(q, blk_mq_make_request);
		else
			blk_queue_make_request(q, blk_sq_make_request);

		blk_mq_queue_reinit(q, cpu_online_mask);
	}

	list_for_each_entry(q, &set->tag_list, tag_set_list)
		blk_mq_unfreeze_queue(q);
}
Contributors
Person Tokens Prop Commits CommitProp
keith busch keith busch 120 100.00% 1 100.00%
Total 120 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);



void blk_mq_disable_hotplug(void)
{
	mutex_lock(&all_q_mutex);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 13 100.00% 1 100.00%
Total 13 100.00% 1 100.00%



void blk_mq_enable_hotplug(void)
{
	mutex_unlock(&all_q_mutex);
}

Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 13 100.00% 1 100.00%
Total 13 100.00% 1 100.00%



static int __init blk_mq_init(void)
{
	blk_mq_cpu_init();

	hotcpu_notifier(blk_mq_queue_reinit_notify, 0);

	return 0;
}
Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 21 95.45% 1 50.00%
tejun heo tejun heo 1 4.55% 1 50.00%
Total 22 100.00% 2 100.00%


subsys_initcall(blk_mq_init);
Overall Contributors
Person Tokens Prop Commits CommitProp
jens axboe jens axboe 6178 59.53% 52 30.95%
christoph hellwig christoph hellwig 1868 18.00% 38 22.62%
keith busch keith busch 577 5.56% 11 6.55%
ming lei ming lei 447 4.31% 11 6.55%
shaohua li shaohua li 282 2.72% 6 3.57%
lei ming lei ming 273 2.63% 11 6.55%
akinobu mita akinobu mita 144 1.39% 5 2.98%
jeff moyer jeff moyer 133 1.28% 2 1.19%
tejun heo tejun heo 108 1.04% 6 3.57%
mike snitzer mike snitzer 86 0.83% 2 1.19%
catalin marinas catalin marinas 27 0.26% 1 0.60%
joe lawrence joe lawrence 25 0.24% 1 0.60%
dan williams dan williams 25 0.24% 1 0.60%
kent overstreet kent overstreet 24 0.23% 1 0.60%
chong yuan chong yuan 21 0.20% 1 0.60%
paolo bonzini paolo bonzini 20 0.19% 2 1.19%
nicholas bellinger nicholas bellinger 18 0.17% 1 0.60%
robert elliott robert elliott 18 0.17% 2 1.19%
raghavendra k t* (same as raghavendra koushik) raghavendra k t* (same as raghavendra koushik) 16 0.15% 2 1.19%
omar sandoval omar sandoval 14 0.13% 1 0.60%
thomas gleixner thomas gleixner 12 0.12% 1 0.60%
hannes reinecke hannes reinecke 11 0.11% 1 0.60%
lin ming lin ming 11 0.11% 1 0.60%
bart van assche bart van assche 9 0.09% 1 0.60%
fang wei fang wei 9 0.09% 1 0.60%
tony battersby tony battersby 8 0.08% 1 0.60%
david hildenbrand david hildenbrand 6 0.06% 1 0.60%
dave hansen dave hansen 3 0.03% 1 0.60%
linus torvalds linus torvalds 2 0.02% 1 0.60%
bartlomiej zolnierkiewicz bartlomiej zolnierkiewicz 2 0.02% 1 0.60%
frederic weisbecker frederic weisbecker 1 0.01% 1 0.60%
Total 10378 100.00% 168 100.00%
  Directory: block

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
	Person	Tokens	Prop	Commits	CommitProp
jens axboe	jens axboe	51	100.00%	3	100.00%
	Total	51	100.00%	3	100.00%
cregit-Linux how code gets into the kernel

Release 4.7 block/blk-mq.c

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors
