summaryrefslogtreecommitdiff
path: root/block/mq-deadline.c
diff options
context:
space:
mode:
Diffstat (limited to 'block/mq-deadline.c')
-rw-r--r--block/mq-deadline.c815
1 files changed, 0 insertions, 815 deletions
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
deleted file mode 100644
index 8eea2cbf2bf4..000000000000
--- a/block/mq-deadline.c
+++ /dev/null
@@ -1,815 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * MQ Deadline i/o scheduler - adaptation of the legacy deadline scheduler,
- * for the blk-mq scheduling framework
- *
- * Copyright (C) 2016 Jens Axboe <axboe@kernel.dk>
- */
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/blkdev.h>
-#include <linux/blk-mq.h>
-#include <linux/elevator.h>
-#include <linux/bio.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/compiler.h>
-#include <linux/rbtree.h>
-#include <linux/sbitmap.h>
-
-#include <trace/events/block.h>
-
-#include "blk.h"
-#include "blk-mq.h"
-#include "blk-mq-debugfs.h"
-#include "blk-mq-tag.h"
-#include "blk-mq-sched.h"
-
-/*
- * See Documentation/block/deadline-iosched.rst
- */
-static const int read_expire = HZ / 2; /* max time before a read is submitted. */
-static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
-static const int writes_starved = 2; /* max times reads can starve a write */
-static const int fifo_batch = 16; /* # of sequential requests treated as one
- by the above parameters. For throughput. */
-
-struct deadline_data {
- /*
- * run time data
- */
-
- /*
- * requests (deadline_rq s) are present on both sort_list and fifo_list
- */
- struct rb_root sort_list[2];
- struct list_head fifo_list[2];
-
- /*
- * next in sort order. read, write or both are NULL
- */
- struct request *next_rq[2];
- unsigned int batching; /* number of sequential requests made */
- unsigned int starved; /* times reads have starved writes */
-
- /*
- * settings that change how the i/o scheduler behaves
- */
- int fifo_expire[2];
- int fifo_batch;
- int writes_starved;
- int front_merges;
-
- spinlock_t lock;
- spinlock_t zone_lock;
- struct list_head dispatch;
-};
-
-static inline struct rb_root *
-deadline_rb_root(struct deadline_data *dd, struct request *rq)
-{
- return &dd->sort_list[rq_data_dir(rq)];
-}
-
-/*
- * get the request after `rq' in sector-sorted order
- */
-static inline struct request *
-deadline_latter_request(struct request *rq)
-{
- struct rb_node *node = rb_next(&rq->rb_node);
-
- if (node)
- return rb_entry_rq(node);
-
- return NULL;
-}
-
-static void
-deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
-{
- struct rb_root *root = deadline_rb_root(dd, rq);
-
- elv_rb_add(root, rq);
-}
-
-static inline void
-deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
-{
- const int data_dir = rq_data_dir(rq);
-
- if (dd->next_rq[data_dir] == rq)
- dd->next_rq[data_dir] = deadline_latter_request(rq);
-
- elv_rb_del(deadline_rb_root(dd, rq), rq);
-}
-
-/*
- * remove rq from rbtree and fifo.
- */
-static void deadline_remove_request(struct request_queue *q, struct request *rq)
-{
- struct deadline_data *dd = q->elevator->elevator_data;
-
- list_del_init(&rq->queuelist);
-
- /*
- * We might not be on the rbtree, if we are doing an insert merge
- */
- if (!RB_EMPTY_NODE(&rq->rb_node))
- deadline_del_rq_rb(dd, rq);
-
- elv_rqhash_del(q, rq);
- if (q->last_merge == rq)
- q->last_merge = NULL;
-}
-
-static void dd_request_merged(struct request_queue *q, struct request *req,
- enum elv_merge type)
-{
- struct deadline_data *dd = q->elevator->elevator_data;
-
- /*
- * if the merge was a front merge, we need to reposition request
- */
- if (type == ELEVATOR_FRONT_MERGE) {
- elv_rb_del(deadline_rb_root(dd, req), req);
- deadline_add_rq_rb(dd, req);
- }
-}
-
-static void dd_merged_requests(struct request_queue *q, struct request *req,
- struct request *next)
-{
- /*
- * if next expires before rq, assign its expire time to rq
- * and move into next position (next will be deleted) in fifo
- */
- if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
- if (time_before((unsigned long)next->fifo_time,
- (unsigned long)req->fifo_time)) {
- list_move(&req->queuelist, &next->queuelist);
- req->fifo_time = next->fifo_time;
- }
- }
-
- /*
- * kill knowledge of next, this one is a goner
- */
- deadline_remove_request(q, next);
-}
-
-/*
- * move an entry to dispatch queue
- */
-static void
-deadline_move_request(struct deadline_data *dd, struct request *rq)
-{
- const int data_dir = rq_data_dir(rq);
-
- dd->next_rq[READ] = NULL;
- dd->next_rq[WRITE] = NULL;
- dd->next_rq[data_dir] = deadline_latter_request(rq);
-
- /*
- * take it off the sort and fifo list
- */
- deadline_remove_request(rq->q, rq);
-}
-
-/*
- * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
- * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
- */
-static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
-{
- struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next);
-
- /*
- * rq is expired!
- */
- if (time_after_eq(jiffies, (unsigned long)rq->fifo_time))
- return 1;
-
- return 0;
-}
-
-/*
- * For the specified data direction, return the next request to
- * dispatch using arrival ordered lists.
- */
-static struct request *
-deadline_fifo_request(struct deadline_data *dd, int data_dir)
-{
- struct request *rq;
- unsigned long flags;
-
- if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE))
- return NULL;
-
- if (list_empty(&dd->fifo_list[data_dir]))
- return NULL;
-
- rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
- if (data_dir == READ || !blk_queue_is_zoned(rq->q))
- return rq;
-
- /*
- * Look for a write request that can be dispatched, that is one with
- * an unlocked target zone.
- */
- spin_lock_irqsave(&dd->zone_lock, flags);
- list_for_each_entry(rq, &dd->fifo_list[WRITE], queuelist) {
- if (blk_req_can_dispatch_to_zone(rq))
- goto out;
- }
- rq = NULL;
-out:
- spin_unlock_irqrestore(&dd->zone_lock, flags);
-
- return rq;
-}
-
-/*
- * For the specified data direction, return the next request to
- * dispatch using sector position sorted lists.
- */
-static struct request *
-deadline_next_request(struct deadline_data *dd, int data_dir)
-{
- struct request *rq;
- unsigned long flags;
-
- if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE))
- return NULL;
-
- rq = dd->next_rq[data_dir];
- if (!rq)
- return NULL;
-
- if (data_dir == READ || !blk_queue_is_zoned(rq->q))
- return rq;
-
- /*
- * Look for a write request that can be dispatched, that is one with
- * an unlocked target zone.
- */
- spin_lock_irqsave(&dd->zone_lock, flags);
- while (rq) {
- if (blk_req_can_dispatch_to_zone(rq))
- break;
- rq = deadline_latter_request(rq);
- }
- spin_unlock_irqrestore(&dd->zone_lock, flags);
-
- return rq;
-}
-
-/*
- * deadline_dispatch_requests selects the best request according to
- * read/write expire, fifo_batch, etc
- */
-static struct request *__dd_dispatch_request(struct deadline_data *dd)
-{
- struct request *rq, *next_rq;
- bool reads, writes;
- int data_dir;
-
- if (!list_empty(&dd->dispatch)) {
- rq = list_first_entry(&dd->dispatch, struct request, queuelist);
- list_del_init(&rq->queuelist);
- goto done;
- }
-
- reads = !list_empty(&dd->fifo_list[READ]);
- writes = !list_empty(&dd->fifo_list[WRITE]);
-
- /*
- * batches are currently reads XOR writes
- */
- rq = deadline_next_request(dd, WRITE);
- if (!rq)
- rq = deadline_next_request(dd, READ);
-
- if (rq && dd->batching < dd->fifo_batch)
- /* we have a next request are still entitled to batch */
- goto dispatch_request;
-
- /*
- * at this point we are not running a batch. select the appropriate
- * data direction (read / write)
- */
-
- if (reads) {
- BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ]));
-
- if (deadline_fifo_request(dd, WRITE) &&
- (dd->starved++ >= dd->writes_starved))
- goto dispatch_writes;
-
- data_dir = READ;
-
- goto dispatch_find_request;
- }
-
- /*
- * there are either no reads or writes have been starved
- */
-
- if (writes) {
-dispatch_writes:
- BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[WRITE]));
-
- dd->starved = 0;
-
- data_dir = WRITE;
-
- goto dispatch_find_request;
- }
-
- return NULL;
-
-dispatch_find_request:
- /*
- * we are not running a batch, find best request for selected data_dir
- */
- next_rq = deadline_next_request(dd, data_dir);
- if (deadline_check_fifo(dd, data_dir) || !next_rq) {
- /*
- * A deadline has expired, the last request was in the other
- * direction, or we have run out of higher-sectored requests.
- * Start again from the request with the earliest expiry time.
- */
- rq = deadline_fifo_request(dd, data_dir);
- } else {
- /*
- * The last req was the same dir and we have a next request in
- * sort order. No expired requests so continue on from here.
- */
- rq = next_rq;
- }
-
- /*
- * For a zoned block device, if we only have writes queued and none of
- * them can be dispatched, rq will be NULL.
- */
- if (!rq)
- return NULL;
-
- dd->batching = 0;
-
-dispatch_request:
- /*
- * rq is the selected appropriate request.
- */
- dd->batching++;
- deadline_move_request(dd, rq);
-done:
- /*
- * If the request needs its target zone locked, do it.
- */
- blk_req_zone_write_lock(rq);
- rq->rq_flags |= RQF_STARTED;
- return rq;
-}
-
-/*
- * One confusing aspect here is that we get called for a specific
- * hardware queue, but we may return a request that is for a
- * different hardware queue. This is because mq-deadline has shared
- * state for all hardware queues, in terms of sorting, FIFOs, etc.
- */
-static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
-{
- struct deadline_data *dd = hctx->queue->elevator->elevator_data;
- struct request *rq;
-
- spin_lock(&dd->lock);
- rq = __dd_dispatch_request(dd);
- spin_unlock(&dd->lock);
-
- return rq;
-}
-
-static void dd_exit_queue(struct elevator_queue *e)
-{
- struct deadline_data *dd = e->elevator_data;
-
- BUG_ON(!list_empty(&dd->fifo_list[READ]));
- BUG_ON(!list_empty(&dd->fifo_list[WRITE]));
-
- kfree(dd);
-}
-
-/*
- * initialize elevator private data (deadline_data).
- */
-static int dd_init_queue(struct request_queue *q, struct elevator_type *e)
-{
- struct deadline_data *dd;
- struct elevator_queue *eq;
-
- eq = elevator_alloc(q, e);
- if (!eq)
- return -ENOMEM;
-
- dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
- if (!dd) {
- kobject_put(&eq->kobj);
- return -ENOMEM;
- }
- eq->elevator_data = dd;
-
- INIT_LIST_HEAD(&dd->fifo_list[READ]);
- INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
- dd->sort_list[READ] = RB_ROOT;
- dd->sort_list[WRITE] = RB_ROOT;
- dd->fifo_expire[READ] = read_expire;
- dd->fifo_expire[WRITE] = write_expire;
- dd->writes_starved = writes_starved;
- dd->front_merges = 1;
- dd->fifo_batch = fifo_batch;
- spin_lock_init(&dd->lock);
- spin_lock_init(&dd->zone_lock);
- INIT_LIST_HEAD(&dd->dispatch);
-
- q->elevator = eq;
- return 0;
-}
-
-static int dd_request_merge(struct request_queue *q, struct request **rq,
- struct bio *bio)
-{
- struct deadline_data *dd = q->elevator->elevator_data;
- sector_t sector = bio_end_sector(bio);
- struct request *__rq;
-
- if (!dd->front_merges)
- return ELEVATOR_NO_MERGE;
-
- __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
- if (__rq) {
- BUG_ON(sector != blk_rq_pos(__rq));
-
- if (elv_bio_merge_ok(__rq, bio)) {
- *rq = __rq;
- return ELEVATOR_FRONT_MERGE;
- }
- }
-
- return ELEVATOR_NO_MERGE;
-}
-
-static bool dd_bio_merge(struct request_queue *q, struct bio *bio,
- unsigned int nr_segs)
-{
- struct deadline_data *dd = q->elevator->elevator_data;
- struct request *free = NULL;
- bool ret;
-
- spin_lock(&dd->lock);
- ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free);
- spin_unlock(&dd->lock);
-
- if (free)
- blk_mq_free_request(free);
-
- return ret;
-}
-
-/*
- * add rq to rbtree and fifo
- */
-static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
- bool at_head)
-{
- struct request_queue *q = hctx->queue;
- struct deadline_data *dd = q->elevator->elevator_data;
- const int data_dir = rq_data_dir(rq);
-
- /*
- * This may be a requeue of a write request that has locked its
- * target zone. If it is the case, this releases the zone lock.
- */
- blk_req_zone_write_unlock(rq);
-
- if (blk_mq_sched_try_insert_merge(q, rq))
- return;
-
- trace_block_rq_insert(rq);
-
- if (at_head) {
- list_add(&rq->queuelist, &dd->dispatch);
- } else {
- deadline_add_rq_rb(dd, rq);
-
- if (rq_mergeable(rq)) {
- elv_rqhash_add(q, rq);
- if (!q->last_merge)
- q->last_merge = rq;
- }
-
- /*
- * set expire time and add to fifo list
- */
- rq->fifo_time = jiffies + dd->fifo_expire[data_dir];
- list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]);
- }
-}
-
-static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
- struct list_head *list, bool at_head)
-{
- struct request_queue *q = hctx->queue;
- struct deadline_data *dd = q->elevator->elevator_data;
-
- spin_lock(&dd->lock);
- while (!list_empty(list)) {
- struct request *rq;
-
- rq = list_first_entry(list, struct request, queuelist);
- list_del_init(&rq->queuelist);
- dd_insert_request(hctx, rq, at_head);
- }
- spin_unlock(&dd->lock);
-}
-
-/*
- * Nothing to do here. This is defined only to ensure that .finish_request
- * method is called upon request completion.
- */
-static void dd_prepare_request(struct request *rq)
-{
-}
-
-/*
- * For zoned block devices, write unlock the target zone of
- * completed write requests. Do this while holding the zone lock
- * spinlock so that the zone is never unlocked while deadline_fifo_request()
- * or deadline_next_request() are executing. This function is called for
- * all requests, whether or not these requests complete successfully.
- *
- * For a zoned block device, __dd_dispatch_request() may have stopped
- * dispatching requests if all the queued requests are write requests directed
- * at zones that are already locked due to on-going write requests. To ensure
- * write request dispatch progress in this case, mark the queue as needing a
- * restart to ensure that the queue is run again after completion of the
- * request and zones being unlocked.
- */
-static void dd_finish_request(struct request *rq)
-{
- struct request_queue *q = rq->q;
-
- if (blk_queue_is_zoned(q)) {
- struct deadline_data *dd = q->elevator->elevator_data;
- unsigned long flags;
-
- spin_lock_irqsave(&dd->zone_lock, flags);
- blk_req_zone_write_unlock(rq);
- if (!list_empty(&dd->fifo_list[WRITE]))
- blk_mq_sched_mark_restart_hctx(rq->mq_hctx);
- spin_unlock_irqrestore(&dd->zone_lock, flags);
- }
-}
-
-static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
-{
- struct deadline_data *dd = hctx->queue->elevator->elevator_data;
-
- return !list_empty_careful(&dd->dispatch) ||
- !list_empty_careful(&dd->fifo_list[0]) ||
- !list_empty_careful(&dd->fifo_list[1]);
-}
-
-/*
- * sysfs parts below
- */
-static ssize_t
-deadline_var_show(int var, char *page)
-{
- return sprintf(page, "%d\n", var);
-}
-
-static void
-deadline_var_store(int *var, const char *page)
-{
- char *p = (char *) page;
-
- *var = simple_strtol(p, &p, 10);
-}
-
-#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
-static ssize_t __FUNC(struct elevator_queue *e, char *page) \
-{ \
- struct deadline_data *dd = e->elevator_data; \
- int __data = __VAR; \
- if (__CONV) \
- __data = jiffies_to_msecs(__data); \
- return deadline_var_show(__data, (page)); \
-}
-SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[READ], 1);
-SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[WRITE], 1);
-SHOW_FUNCTION(deadline_writes_starved_show, dd->writes_starved, 0);
-SHOW_FUNCTION(deadline_front_merges_show, dd->front_merges, 0);
-SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0);
-#undef SHOW_FUNCTION
-
-#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
-static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
-{ \
- struct deadline_data *dd = e->elevator_data; \
- int __data; \
- deadline_var_store(&__data, (page)); \
- if (__data < (MIN)) \
- __data = (MIN); \
- else if (__data > (MAX)) \
- __data = (MAX); \
- if (__CONV) \
- *(__PTR) = msecs_to_jiffies(__data); \
- else \
- *(__PTR) = __data; \
- return count; \
-}
-STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[READ], 0, INT_MAX, 1);
-STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[WRITE], 0, INT_MAX, 1);
-STORE_FUNCTION(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0);
-STORE_FUNCTION(deadline_front_merges_store, &dd->front_merges, 0, 1, 0);
-STORE_FUNCTION(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX, 0);
-#undef STORE_FUNCTION
-
-#define DD_ATTR(name) \
- __ATTR(name, 0644, deadline_##name##_show, deadline_##name##_store)
-
-static struct elv_fs_entry deadline_attrs[] = {
- DD_ATTR(read_expire),
- DD_ATTR(write_expire),
- DD_ATTR(writes_starved),
- DD_ATTR(front_merges),
- DD_ATTR(fifo_batch),
- __ATTR_NULL
-};
-
-#ifdef CONFIG_BLK_DEBUG_FS
-#define DEADLINE_DEBUGFS_DDIR_ATTRS(ddir, name) \
-static void *deadline_##name##_fifo_start(struct seq_file *m, \
- loff_t *pos) \
- __acquires(&dd->lock) \
-{ \
- struct request_queue *q = m->private; \
- struct deadline_data *dd = q->elevator->elevator_data; \
- \
- spin_lock(&dd->lock); \
- return seq_list_start(&dd->fifo_list[ddir], *pos); \
-} \
- \
-static void *deadline_##name##_fifo_next(struct seq_file *m, void *v, \
- loff_t *pos) \
-{ \
- struct request_queue *q = m->private; \
- struct deadline_data *dd = q->elevator->elevator_data; \
- \
- return seq_list_next(v, &dd->fifo_list[ddir], pos); \
-} \
- \
-static void deadline_##name##_fifo_stop(struct seq_file *m, void *v) \
- __releases(&dd->lock) \
-{ \
- struct request_queue *q = m->private; \
- struct deadline_data *dd = q->elevator->elevator_data; \
- \
- spin_unlock(&dd->lock); \
-} \
- \
-static const struct seq_operations deadline_##name##_fifo_seq_ops = { \
- .start = deadline_##name##_fifo_start, \
- .next = deadline_##name##_fifo_next, \
- .stop = deadline_##name##_fifo_stop, \
- .show = blk_mq_debugfs_rq_show, \
-}; \
- \
-static int deadline_##name##_next_rq_show(void *data, \
- struct seq_file *m) \
-{ \
- struct request_queue *q = data; \
- struct deadline_data *dd = q->elevator->elevator_data; \
- struct request *rq = dd->next_rq[ddir]; \
- \
- if (rq) \
- __blk_mq_debugfs_rq_show(m, rq); \
- return 0; \
-}
-DEADLINE_DEBUGFS_DDIR_ATTRS(READ, read)
-DEADLINE_DEBUGFS_DDIR_ATTRS(WRITE, write)
-#undef DEADLINE_DEBUGFS_DDIR_ATTRS
-
-static int deadline_batching_show(void *data, struct seq_file *m)
-{
- struct request_queue *q = data;
- struct deadline_data *dd = q->elevator->elevator_data;
-
- seq_printf(m, "%u\n", dd->batching);
- return 0;
-}
-
-static int deadline_starved_show(void *data, struct seq_file *m)
-{
- struct request_queue *q = data;
- struct deadline_data *dd = q->elevator->elevator_data;
-
- seq_printf(m, "%u\n", dd->starved);
- return 0;
-}
-
-static void *deadline_dispatch_start(struct seq_file *m, loff_t *pos)
- __acquires(&dd->lock)
-{
- struct request_queue *q = m->private;
- struct deadline_data *dd = q->elevator->elevator_data;
-
- spin_lock(&dd->lock);
- return seq_list_start(&dd->dispatch, *pos);
-}
-
-static void *deadline_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
-{
- struct request_queue *q = m->private;
- struct deadline_data *dd = q->elevator->elevator_data;
-
- return seq_list_next(v, &dd->dispatch, pos);
-}
-
-static void deadline_dispatch_stop(struct seq_file *m, void *v)
- __releases(&dd->lock)
-{
- struct request_queue *q = m->private;
- struct deadline_data *dd = q->elevator->elevator_data;
-
- spin_unlock(&dd->lock);
-}
-
-static const struct seq_operations deadline_dispatch_seq_ops = {
- .start = deadline_dispatch_start,
- .next = deadline_dispatch_next,
- .stop = deadline_dispatch_stop,
- .show = blk_mq_debugfs_rq_show,
-};
-
-#define DEADLINE_QUEUE_DDIR_ATTRS(name) \
- {#name "_fifo_list", 0400, .seq_ops = &deadline_##name##_fifo_seq_ops}, \
- {#name "_next_rq", 0400, deadline_##name##_next_rq_show}
-static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
- DEADLINE_QUEUE_DDIR_ATTRS(read),
- DEADLINE_QUEUE_DDIR_ATTRS(write),
- {"batching", 0400, deadline_batching_show},
- {"starved", 0400, deadline_starved_show},
- {"dispatch", 0400, .seq_ops = &deadline_dispatch_seq_ops},
- {},
-};
-#undef DEADLINE_QUEUE_DDIR_ATTRS
-#endif
-
-static struct elevator_type mq_deadline = {
- .ops = {
- .insert_requests = dd_insert_requests,
- .dispatch_request = dd_dispatch_request,
- .prepare_request = dd_prepare_request,
- .finish_request = dd_finish_request,
- .next_request = elv_rb_latter_request,
- .former_request = elv_rb_former_request,
- .bio_merge = dd_bio_merge,
- .request_merge = dd_request_merge,
- .requests_merged = dd_merged_requests,
- .request_merged = dd_request_merged,
- .has_work = dd_has_work,
- .init_sched = dd_init_queue,
- .exit_sched = dd_exit_queue,
- },
-
-#ifdef CONFIG_BLK_DEBUG_FS
- .queue_debugfs_attrs = deadline_queue_debugfs_attrs,
-#endif
- .elevator_attrs = deadline_attrs,
- .elevator_name = "mq-deadline",
- .elevator_alias = "deadline",
- .elevator_features = ELEVATOR_F_ZBD_SEQ_WRITE,
- .elevator_owner = THIS_MODULE,
-};
-MODULE_ALIAS("mq-deadline-iosched");
-
-static int __init deadline_init(void)
-{
- return elv_register(&mq_deadline);
-}
-
-static void __exit deadline_exit(void)
-{
- elv_unregister(&mq_deadline);
-}
-
-module_init(deadline_init);
-module_exit(deadline_exit);
-
-MODULE_AUTHOR("Jens Axboe");
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("MQ deadline IO scheduler");