diff options
Diffstat (limited to 'drivers/block/deadline-iosched.c')
| -rw-r--r-- | drivers/block/deadline-iosched.c | 965 |
1 files changed, 0 insertions, 965 deletions
diff --git a/drivers/block/deadline-iosched.c b/drivers/block/deadline-iosched.c deleted file mode 100644 index 52a3ae5289a..00000000000 --- a/drivers/block/deadline-iosched.c +++ /dev/null @@ -1,965 +0,0 @@ -/* - * linux/drivers/block/deadline-iosched.c - * - * Deadline i/o scheduler. - * - * Copyright (C) 2002 Jens Axboe <axboe@suse.de> - */ -#include <linux/kernel.h> -#include <linux/fs.h> -#include <linux/blkdev.h> -#include <linux/elevator.h> -#include <linux/bio.h> -#include <linux/config.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/init.h> -#include <linux/compiler.h> -#include <linux/hash.h> -#include <linux/rbtree.h> - -/* - * See Documentation/block/deadline-iosched.txt - */ -static int read_expire = HZ / 2; /* max time before a read is submitted. */ -static int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */ -static int writes_starved = 2; /* max times reads can starve a write */ -static int fifo_batch = 16; /* # of sequential requests treated as one - by the above parameters. For throughput. */ - -static const int deadline_hash_shift = 5; -#define DL_HASH_BLOCK(sec) ((sec) >> 3) -#define DL_HASH_FN(sec) (hash_long(DL_HASH_BLOCK((sec)), deadline_hash_shift)) -#define DL_HASH_ENTRIES (1 << deadline_hash_shift) -#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) -#define list_entry_hash(ptr) list_entry((ptr), struct deadline_rq, hash) -#define ON_HASH(drq) (drq)->on_hash - -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 deadline_rq *next_drq[2]; - struct list_head *dispatch; /* driver dispatch queue */ - struct list_head *hash; /* request hash */ - unsigned int batching; /* number of sequential requests made */ - sector_t last_sector; /* head position */ - 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; - - mempool_t *drq_pool; -}; - -/* - * pre-request data. - */ -struct deadline_rq { - /* - * rbtree index, key is the starting offset - */ - struct rb_node rb_node; - sector_t rb_key; - - struct request *request; - - /* - * request hash, key is the ending offset (for back merge lookup) - */ - struct list_head hash; - char on_hash; - - /* - * expire fifo - */ - struct list_head fifo; - unsigned long expires; -}; - -static void deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq); - -static kmem_cache_t *drq_pool; - -#define RQ_DATA(rq) ((struct deadline_rq *) (rq)->elevator_private) - -/* - * the back merge hash support functions - */ -static inline void __deadline_del_drq_hash(struct deadline_rq *drq) -{ - drq->on_hash = 0; - list_del_init(&drq->hash); -} - -static inline void deadline_del_drq_hash(struct deadline_rq *drq) -{ - if (ON_HASH(drq)) - __deadline_del_drq_hash(drq); -} - -static void -deadline_remove_merge_hints(request_queue_t *q, struct deadline_rq *drq) -{ - deadline_del_drq_hash(drq); - - if (q->last_merge == drq->request) - q->last_merge = NULL; -} - -static inline void -deadline_add_drq_hash(struct deadline_data *dd, struct deadline_rq *drq) -{ - struct request *rq = drq->request; - - BUG_ON(ON_HASH(drq)); - - drq->on_hash = 1; - list_add(&drq->hash, &dd->hash[DL_HASH_FN(rq_hash_key(rq))]); -} - -/* - * move hot entry to front of chain - */ -static inline void -deadline_hot_drq_hash(struct deadline_data *dd, struct deadline_rq *drq) -{ - struct request *rq = drq->request; - struct list_head *head = &dd->hash[DL_HASH_FN(rq_hash_key(rq))]; - - if (ON_HASH(drq) && drq->hash.prev != head) { - list_del(&drq->hash); - list_add(&drq->hash, head); - } -} - -static struct request * -deadline_find_drq_hash(struct deadline_data *dd, sector_t offset) -{ - struct list_head *hash_list = &dd->hash[DL_HASH_FN(offset)]; - struct list_head *entry, *next = hash_list->next; - - while ((entry = next) != hash_list) { - struct deadline_rq *drq = list_entry_hash(entry); - struct request *__rq = drq->request; - - next = entry->next; - - BUG_ON(!ON_HASH(drq)); - - if (!rq_mergeable(__rq)) { - __deadline_del_drq_hash(drq); - continue; - } - - if (rq_hash_key(__rq) == offset) - return __rq; - } - - return NULL; -} - -/* - * rb tree support functions - */ -#define RB_NONE (2) -#define RB_EMPTY(root) ((root)->rb_node == NULL) -#define ON_RB(node) ((node)->rb_color != RB_NONE) -#define RB_CLEAR(node) ((node)->rb_color = RB_NONE) -#define rb_entry_drq(node) rb_entry((node), struct deadline_rq, rb_node) -#define DRQ_RB_ROOT(dd, drq) (&(dd)->sort_list[rq_data_dir((drq)->request)]) -#define rq_rb_key(rq) (rq)->sector - -static struct deadline_rq * -__deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq) -{ - struct rb_node **p = &DRQ_RB_ROOT(dd, drq)->rb_node; - struct rb_node *parent = NULL; - struct deadline_rq *__drq; - - while (*p) { - parent = *p; - __drq = rb_entry_drq(parent); - - if (drq->rb_key < __drq->rb_key) - p = &(*p)->rb_left; - else if (drq->rb_key > __drq->rb_key) - p = &(*p)->rb_right; - else - return __drq; - } - - rb_link_node(&drq->rb_node, parent, p); - return NULL; -} - -static void -deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq) -{ - struct deadline_rq *__alias; - - drq->rb_key = rq_rb_key(drq->request); - -retry: - __alias = __deadline_add_drq_rb(dd, drq); - if (!__alias) { - rb_insert_color(&drq->rb_node, DRQ_RB_ROOT(dd, drq)); - return; - } - - deadline_move_request(dd, __alias); - goto retry; -} - -static inline void -deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq) -{ - const int data_dir = rq_data_dir(drq->request); - - if (dd->next_drq[data_dir] == drq) { - struct rb_node *rbnext = rb_next(&drq->rb_node); - - dd->next_drq[data_dir] = NULL; - if (rbnext) - dd->next_drq[data_dir] = rb_entry_drq(rbnext); - } - - if (ON_RB(&drq->rb_node)) { - rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq)); - RB_CLEAR(&drq->rb_node); - } -} - -static struct request * -deadline_find_drq_rb(struct deadline_data *dd, sector_t sector, int data_dir) -{ - struct rb_node *n = dd->sort_list[data_dir].rb_node; - struct deadline_rq *drq; - - while (n) { - drq = rb_entry_drq(n); - - if (sector < drq->rb_key) - n = n->rb_left; - else if (sector > drq->rb_key) - n = n->rb_right; - else - return drq->request; - } - - return NULL; -} - -/* - * deadline_find_first_drq finds the first (lowest sector numbered) request - * for the specified data_dir. Used to sweep back to the start of the disk - * (1-way elevator) after we process the last (highest sector) request. - */ -static struct deadline_rq * -deadline_find_first_drq(struct deadline_data *dd, int data_dir) -{ - struct rb_node *n = dd->sort_list[data_dir].rb_node; - - for (;;) { - if (n->rb_left == NULL) - return rb_entry_drq(n); - - n = n->rb_left; - } -} - -/* - * add drq to rbtree and fifo - */ -static inline void -deadline_add_request(struct request_queue *q, struct request *rq) -{ - struct deadline_data *dd = q->elevator->elevator_data; - struct deadline_rq *drq = RQ_DATA(rq); - - const int data_dir = rq_data_dir(drq->request); - - deadline_add_drq_rb(dd, drq); - /* - * set expire time (only used for reads) and add to fifo list - */ - drq->expires = jiffies + dd->fifo_expire[data_dir]; - list_add_tail(&drq->fifo, &dd->fifo_list[data_dir]); - - if (rq_mergeable(rq)) { - deadline_add_drq_hash(dd, drq); - - if (!q->last_merge) - q->last_merge = rq; - } -} - -/* - * remove rq from rbtree, fifo, and hash - */ -static void deadline_remove_request(request_queue_t *q, struct request *rq) -{ - struct deadline_rq *drq = RQ_DATA(rq); - - if (drq) { - struct deadline_data *dd = q->elevator->elevator_data; - - list_del_init(&drq->fifo); - deadline_remove_merge_hints(q, drq); - deadline_del_drq_rb(dd, drq); - } -} - -static int -deadline_merge(request_queue_t *q, struct request **req, struct bio *bio) -{ - struct deadline_data *dd = q->elevator->elevator_data; - struct request *__rq; - int ret; - - /* - * try last_merge to avoid going to hash - */ - ret = elv_try_last_merge(q, bio); - if (ret != ELEVATOR_NO_MERGE) { - __rq = q->last_merge; - goto out_insert; - } - - /* - * see if the merge hash can satisfy a back merge - */ - __rq = deadline_find_drq_hash(dd, bio->bi_sector); - if (__rq) { - BUG_ON(__rq->sector + __rq->nr_sectors != bio->bi_sector); - - if (elv_rq_merge_ok(__rq, bio)) { - ret = ELEVATOR_BACK_MERGE; - goto out; - } - } - - /* - * check for front merge - */ - if (dd->front_merges) { - sector_t rb_key = bio->bi_sector + bio_sectors(bio); - - __rq = deadline_find_drq_rb(dd, rb_key, bio_data_dir(bio)); - if (__rq) { - BUG_ON(rb_key != rq_rb_key(__rq)); - - if (elv_rq_merge_ok(__rq, bio)) { - ret = ELEVATOR_FRONT_MERGE; - goto out; - } - } - } - - return ELEVATOR_NO_MERGE; -out: - q->last_merge = __rq; -out_insert: - if (ret) - deadline_hot_drq_hash(dd, RQ_DATA(__rq)); - *req = __rq; - return ret; -} - -static void deadline_merged_request(request_queue_t *q, struct request *req) -{ - struct deadline_data *dd = q->elevator->elevator_data; - struct deadline_rq *drq = RQ_DATA(req); - - /* - * hash always needs to be repositioned, key is end sector - */ - deadline_del_drq_hash(drq); - deadline_add_drq_hash(dd, drq); - - /* - * if the merge was a front merge, we need to reposition request - */ - if (rq_rb_key(req) != drq->rb_key) { - deadline_del_drq_rb(dd, drq); - deadline_add_drq_rb(dd, drq); - } - - q->last_merge = req; -} - -static void -deadline_merged_requests(request_queue_t *q, struct request *req, - struct request *next) -{ - struct deadline_data *dd = q->elevator->elevator_data; - struct deadline_rq *drq = RQ_DATA(req); - struct deadline_rq *dnext = RQ_DATA(next); - - BUG_ON(!drq); - BUG_ON(!dnext); - - /* - * reposition drq (this is the merged request) in hash, and in rbtree - * in case of a front merge - */ - deadline_del_drq_hash(drq); - deadline_add_drq_hash(dd, drq); - - if (rq_rb_key(req) != drq->rb_key) { - deadline_del_drq_rb(dd, drq); - deadline_add_drq_rb(dd, drq); - } - - /* - * if dnext expires before drq, assign its expire time to drq - * and move into dnext position (dnext will be deleted) in fifo - */ - if (!list_empty(&drq->fifo) && !list_empty(&dnext->fifo)) { - if (time_before(dnext->expires, drq->expires)) { - list_move(&drq->fifo, &dnext->fifo); - drq->expires = dnext->expires; - } - } - - /* - * kill knowledge of next, this one is a goner - */ - deadline_remove_request(q, next); -} - -/* - * move request from sort list to dispatch queue. - */ -static inline void -deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq) -{ - request_queue_t *q = drq->request->q; - - deadline_remove_request(q, drq->request); - list_add_tail(&drq->request->queuelist, dd->dispatch); -} - -/* - * move an entry to dispatch queue - */ -static void -deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq) -{ - const int data_dir = rq_data_dir(drq->request); - struct rb_node *rbnext = rb_next(&drq->rb_node); - - dd->next_drq[READ] = NULL; - dd->next_drq[WRITE] = NULL; - - if (rbnext) - dd->next_drq[data_dir] = rb_entry_drq(rbnext); - - dd->last_sector = drq->request->sector + drq->request->nr_sectors; - - /* - * take it off the sort and fifo list, move - * to dispatch queue - */ - deadline_move_to_dispatch(dd, drq); -} - -#define list_entry_fifo(ptr) list_entry((ptr), struct deadline_rq, fifo) - -/* - * deadline_check_fifo returns 0 if there are no expired reads 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 deadline_rq *drq = list_entry_fifo(dd->fifo_list[ddir].next); - - /* - * drq is expired! - */ - if (time_after(jiffies, drq->expires)) - return 1; - - return 0; -} - -/* - * deadline_dispatch_requests selects the best request according to - * read/write expire, fifo_batch, etc - */ -static int deadline_dispatch_requests(struct deadline_data *dd) -{ - const int reads = !list_empty(&dd->fifo_list[READ]); - const int writes = !list_empty(&dd->fifo_list[WRITE]); - struct deadline_rq *drq; - int data_dir; - - /* - * batches are currently reads XOR writes - */ - if (dd->next_drq[WRITE]) - drq = dd->next_drq[WRITE]; - else - drq = dd->next_drq[READ]; - - if (drq) { - /* we have a "next request" */ - - if (dd->last_sector != drq->request->sector) - /* end the batch on a non sequential request */ - dd->batching += dd->fifo_batch; - - if (dd->batching < dd->fifo_batch) - /* we 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(&dd->sort_list[READ])); - - if (writes && (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(&dd->sort_list[WRITE])); - - dd->starved = 0; - - data_dir = WRITE; - - goto dispatch_find_request; - } - - return 0; - -dispatch_find_request: - /* - * we are not running a batch, find best request for selected data_dir - */ - if (deadline_check_fifo(dd, data_dir)) { - /* An expired request exists - satisfy it */ - dd->batching = 0; - drq = list_entry_fifo(dd->fifo_list[data_dir].next); - - } else if (dd->next_drq[data_dir]) { - /* - * The last req was the same dir and we have a next request in - * sort order. No expired requests so continue on from here. - */ - drq = dd->next_drq[data_dir]; - } else { - /* - * The last req was the other direction or we have run out of - * higher-sectored requests. Go back to the lowest sectored - * request (1 way elevator) and start a new batch. - */ - dd->batching = 0; - drq = deadline_find_first_drq(dd, data_dir); - } - -dispatch_request: - /* - * drq is the selected appropriate request. - */ - dd->batching++; - deadline_move_request(dd, drq); - - return 1; -} - -static struct request *deadline_next_request(request_queue_t *q) -{ - struct deadline_data *dd = q->elevator->elevator_data; - struct request *rq; - - /* - * if there are still requests on the dispatch queue, grab the first one - */ - if (!list_empty(dd->dispatch)) { -dispatch: - rq = list_entry_rq(dd->dispatch->next); - return rq; - } - - if (deadline_dispatch_requests(dd)) - goto dispatch; - - return NULL; -} - -static void -deadline_insert_request(request_queue_t *q, struct request *rq, int where) -{ - struct deadline_data *dd = q->elevator->elevator_data; - - /* barriers must flush the reorder queue */ - if (unlikely(rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER) - && where == ELEVATOR_INSERT_SORT)) - where = ELEVATOR_INSERT_BACK; - - switch (where) { - case ELEVATOR_INSERT_BACK: - while (deadline_dispatch_requests(dd)) - ; - list_add_tail(&rq->queuelist, dd->dispatch); - break; - case ELEVATOR_INSERT_FRONT: - list_add(&rq->queuelist, dd->dispatch); - break; - case ELEVATOR_INSERT_SORT: - BUG_ON(!blk_fs_request(rq)); - deadline_add_request(q, rq); - break; - default: - printk("%s: bad insert point %d\n", __FUNCTION__,where); - return; - } -} - -static int deadline_queue_empty(request_queue_t *q) -{ - struct deadline_data *dd = q->elevator->elevator_data; - - if (!list_empty(&dd->fifo_list[WRITE]) - || !list_empty(&dd->fifo_list[READ]) - || !list_empty(dd->dispatch)) - return 0; - - return 1; -} - -static struct request * -deadline_former_request(request_queue_t *q, struct request *rq) -{ - struct deadline_rq *drq = RQ_DATA(rq); - struct rb_node *rbprev = rb_prev(&drq->rb_node); - - if (rbprev) - return rb_entry_drq(rbprev)->request; - - return NULL; -} - -static struct request * -deadline_latter_request(request_queue_t *q, struct request *rq) -{ - struct deadline_rq *drq = RQ_DATA(rq); - struct rb_node *rbnext = rb_next(&drq->rb_node); - - if (rbnext) - return rb_entry_drq(rbnext)->request; - - return NULL; -} - -static void deadline_exit_queue(elevator_t *e) -{ - struct deadline_data *dd = e->elevator_data; - - BUG_ON(!list_empty(&dd->fifo_list[READ])); - BUG_ON(!list_empty(&dd->fifo_list[WRITE])); - - mempool_destroy(dd->drq_pool); - kfree(dd->hash); - kfree(dd); -} - -/* - * initialize elevator private data (deadline_data), and alloc a drq for - * each request on the free lists - */ -static int deadline_init_queue(request_queue_t *q, elevator_t *e) -{ - struct deadline_data *dd; - int i; - - if (!drq_pool) - return -ENOMEM; - - dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node); - if (!dd) - return -ENOMEM; - memset(dd, 0, sizeof(*dd)); - - dd->hash = kmalloc_node(sizeof(struct list_head)*DL_HASH_ENTRIES, - GFP_KERNEL, q->node); - if (!dd->hash) { - kfree(dd); - return -ENOMEM; - } - - dd->drq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab, - mempool_free_slab, drq_pool, q->node); - if (!dd->drq_pool) { - kfree(dd->hash); - kfree(dd); - return -ENOMEM; - } - - for (i = 0; i < DL_HASH_ENTRIES; i++) - INIT_LIST_HEAD(&dd->hash[i]); - - 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->dispatch = &q->queue_head; - 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; - e->elevator_data = dd; - return 0; -} - -static void deadline_put_request(request_queue_t *q, struct request *rq) -{ - struct deadline_data *dd = q->elevator->elevator_data; - struct deadline_rq *drq = RQ_DATA(rq); - - if (drq) { - mempool_free(drq, dd->drq_pool); - rq->elevator_private = NULL; - } -} - -static int -deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio, - int gfp_mask) -{ - struct deadline_data *dd = q->elevator->elevator_data; - struct deadline_rq *drq; - - drq = mempool_alloc(dd->drq_pool, gfp_mask); - if (drq) { - memset(drq, 0, sizeof(*drq)); - RB_CLEAR(&drq->rb_node); - drq->request = rq; - - INIT_LIST_HEAD(&drq->hash); - drq->on_hash = 0; - - INIT_LIST_HEAD(&drq->fifo); - - rq->elevator_private = drq; - return 0; - } - - return 1; -} - -/* - * sysfs parts below - */ -struct deadline_fs_entry { - struct attribute attr; - ssize_t (*show)(struct deadline_data *, char *); - ssize_t (*store)(struct deadline_data *, const char *, size_t); -}; - -static ssize_t -deadline_var_show(int var, char *page) -{ - return sprintf(page, "%d\n", var); -} - -static ssize_t -deadline_var_store(int *var, const char *page, size_t count) -{ - char *p = (char *) page; - - *var = simple_strtol(p, &p, 10); - return count; -} - -#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ -static ssize_t __FUNC(struct deadline_data *dd, char *page) \ -{ \ - int __data = __VAR; \ - if (__CONV) \ - __data = jiffies_to_msecs(__data); \ - return deadline_var_show(__data, (page)); \ -} -SHOW_FUNCTION(deadline_readexpire_show, dd->fifo_expire[READ], 1); -SHOW_FUNCTION(deadline_writeexpire_show, dd->fifo_expire[WRITE], 1); -SHOW_FUNCTION(deadline_writesstarved_show, dd->writes_starved, 0); -SHOW_FUNCTION(deadline_frontmerges_show, dd->front_merges, 0); -SHOW_FUNCTION(deadline_fifobatch_show, dd->fifo_batch, 0); -#undef SHOW_FUNCTION - -#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ -static ssize_t __FUNC(struct deadline_data *dd, const char *page, size_t count) \ -{ \ - int __data; \ - int ret = deadline_var_store(&__data, (page), count); \ - if (__data < (MIN)) \ - __data = (MIN); \ - else if (__data > (MAX)) \ - __data = (MAX); \ - if (__CONV) \ - *(__PTR) = msecs_to_jiffies(__data); \ - else \ - *(__PTR) = __data; \ - return ret; \ -} -STORE_FUNCTION(deadline_readexpire_store, &dd->fifo_expire[READ], 0, INT_MAX, 1); -STORE_FUNCTION(deadline_writeexpire_store, &dd->fifo_expire[WRITE], 0, INT_MAX, 1); -STORE_FUNCTION(deadline_writesstarved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0); -STORE_FUNCTION(deadline_frontmerges_store, &dd->front_merges, 0, 1, 0); -STORE_FUNCTION(deadline_fifobatch_store, &dd->fifo_batch, 0, INT_MAX, 0); -#undef STORE_FUNCTION - -static struct deadline_fs_entry deadline_readexpire_entry = { - .attr = {.name = "read_expire", .mode = S_IRUGO | S_IWUSR }, - .show = deadline_readexpire_show, - .store = deadline_readexpire_store, -}; -static struct deadline_fs_entry deadline_writeexpire_entry = { - .attr = {.name = "write_expire", .mode = S_IRUGO | S_IWUSR }, - .show = deadline_writeexpire_show, - .store = deadline_writeexpire_store, -}; -static struct deadline_fs_entry deadline_writesstarved_entry = { - .attr = {.name = "writes_starved", .mode = S_IRUGO | S_IWUSR }, - .show = deadline_writesstarved_show, - .store = deadline_writesstarved_store, -}; -static struct deadline_fs_entry deadline_frontmerges_entry = { - .attr = {.name = "front_merges", .mode = S_IRUGO | S_IWUSR }, - .show = deadline_frontmerges_show, - .store = deadline_frontmerges_store, -}; -static struct deadline_fs_entry deadline_fifobatch_entry = { - .attr = {.name = "fifo_batch", .mode = S_IRUGO | S_IWUSR }, - .show = deadline_fifobatch_show, - .store = deadline_fifobatch_store, -}; - -static struct attribute *default_attrs[] = { - &deadline_readexpire_entry.attr, - &deadline_writeexpire_entry.attr, - &deadline_writesstarved_entry.attr, - &deadline_frontmerges_entry.attr, - &deadline_fifobatch_entry.attr, - NULL, -}; - -#define to_deadline(atr) container_of((atr), struct deadline_fs_entry, attr) - -static ssize_t -deadline_attr_show(struct kobject *kobj, struct attribute *attr, char *page) -{ - elevator_t *e = container_of(kobj, elevator_t, kobj); - struct deadline_fs_entry *entry = to_deadline(attr); - - if (!entry->show) - return -EIO; - - return entry->show(e->elevator_data, page); -} - -static ssize_t -deadline_attr_store(struct kobject *kobj, struct attribute *attr, - const char *page, size_t length) -{ - elevator_t *e = container_of(kobj, elevator_t, kobj); - struct deadline_fs_entry *entry = to_deadline(attr); - - if (!entry->store) - return -EIO; - - return entry->store(e->elevator_data, page, length); -} - -static struct sysfs_ops deadline_sysfs_ops = { - .show = deadline_attr_show, - .store = deadline_attr_store, -}; - -static struct kobj_type deadline_ktype = { - .sysfs_ops = &deadline_sysfs_ops, - .default_attrs = default_attrs, -}; - -static struct elevator_type iosched_deadline = { - .ops = { - .elevator_merge_fn = deadline_merge, - .elevator_merged_fn = deadline_merged_request, - .elevator_merge_req_fn = deadline_merged_requests, - .elevator_next_req_fn = deadline_next_request, - .elevator_add_req_fn = deadline_insert_request, - .elevator_remove_req_fn = deadline_remove_request, - .elevator_queue_empty_fn = deadline_queue_empty, - .elevator_former_req_fn = deadline_former_request, - .elevator_latter_req_fn = deadline_latter_request, - .elevator_set_req_fn = deadline_set_request, - .elevator_put_req_fn = deadline_put_request, - .elevator_init_fn = deadline_init_queue, - .elevator_exit_fn = deadline_exit_queue, - }, - - .elevator_ktype = &deadline_ktype, - .elevator_name = "deadline", - .elevator_owner = THIS_MODULE, -}; - -static int __init deadline_init(void) -{ - int ret; - - drq_pool = kmem_cache_create("deadline_drq", sizeof(struct deadline_rq), - 0, 0, NULL, NULL); - - if (!drq_pool) - return -ENOMEM; - - ret = elv_register(&iosched_deadline); - if (ret) - kmem_cache_destroy(drq_pool); - - return ret; -} - -static void __exit deadline_exit(void) -{ - kmem_cache_destroy(drq_pool); - elv_unregister(&iosched_deadline); -} - -module_init(deadline_init); -module_exit(deadline_exit); - -MODULE_AUTHOR("Jens Axboe"); -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("deadline IO scheduler"); |