mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
818 lines
21 KiB
818 lines
21 KiB
// 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 <[email protected]> |
|
*/ |
|
#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 || blk_rq_is_passthrough(rq)) { |
|
if (at_head) |
|
list_add(&rq->queuelist, &dd->dispatch); |
|
else |
|
list_add_tail(&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");
|
|
|