/*
* Anticipatory & deadline i/o scheduler.
*
- * Copyright (C) 2002 Jens Axboe <axboe@suse.de>
+ * Copyright (C) 2002 Jens Axboe <axboe@kernel.dk>
* Nick Piggin <nickpiggin@yahoo.com.au>
*
*/
#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>
#include <linux/interrupt.h>
struct rb_root sort_list[2];
struct list_head fifo_list[2];
- struct as_rq *next_arq[2]; /* next in sort order */
+ struct request *next_rq[2]; /* next in sort order */
sector_t last_sector[2]; /* last REQ_SYNC & REQ_ASYNC sectors */
- struct list_head *hash; /* request hash */
unsigned long exit_prob; /* probability a task will exit while
being waited on */
int write_batch_count; /* max # of reqs in a write batch */
int current_write_count; /* how many requests left this batch */
int write_batch_idled; /* has the write batch gone idle? */
- mempool_t *arq_pool;
enum anticipation_status antic_status;
unsigned long antic_start; /* jiffies: when it started */
unsigned long antic_expire;
};
-#define list_entry_fifo(ptr) list_entry((ptr), struct as_rq, fifo)
-
/*
* per-request data.
*/
AS_RQ_POSTSCHED, /* when they shouldn't be */
};
-struct as_rq {
- /*
- * rbtree index, key is the starting offset
- */
- struct rb_node rb_node;
- sector_t rb_key;
-
- struct request *request;
-
- struct io_context *io_context; /* The submitting task */
-
- /*
- * request hash, key is the ending offset (for back merge lookup)
- */
- struct list_head hash;
- unsigned int on_hash;
-
- /*
- * expire fifo
- */
- struct list_head fifo;
- unsigned long expires;
+#define RQ_IOC(rq) ((struct io_context *) (rq)->elevator_private)
+#define RQ_STATE(rq) ((enum arq_state)(rq)->elevator_private2)
+#define RQ_SET_STATE(rq, state) ((rq)->elevator_private2 = (void *) state)
- unsigned int is_sync;
- enum arq_state state;
-};
-
-#define RQ_DATA(rq) ((struct as_rq *) (rq)->elevator_private)
-
-static kmem_cache_t *arq_pool;
-
-static atomic_t ioc_count = ATOMIC_INIT(0);
+static DEFINE_PER_CPU(unsigned long, ioc_count);
static struct completion *ioc_gone;
-static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq);
+static void as_move_to_dispatch(struct as_data *ad, struct request *rq);
static void as_antic_stop(struct as_data *ad);
/*
static void free_as_io_context(struct as_io_context *aic)
{
kfree(aic);
- if (atomic_dec_and_test(&ioc_count) && ioc_gone)
+ elv_ioc_count_dec(ioc_count);
+ if (ioc_gone && !elv_ioc_count_read(ioc_count))
complete(ioc_gone);
}
ret->seek_total = 0;
ret->seek_samples = 0;
ret->seek_mean = 0;
- atomic_inc(&ioc_count);
+ elv_ioc_count_inc(ioc_count);
}
return ret;
* If the current task has no AS IO context then create one and initialise it.
* Then take a ref on the task's io context and return it.
*/
-static struct io_context *as_get_io_context(void)
+static struct io_context *as_get_io_context(int node)
{
- struct io_context *ioc = get_io_context(GFP_ATOMIC);
+ struct io_context *ioc = get_io_context(GFP_ATOMIC, node);
if (ioc && !ioc->aic) {
ioc->aic = alloc_as_io_context();
if (!ioc->aic) {
return ioc;
}
-static void as_put_io_context(struct as_rq *arq)
+static void as_put_io_context(struct request *rq)
{
struct as_io_context *aic;
- if (unlikely(!arq->io_context))
+ if (unlikely(!RQ_IOC(rq)))
return;
- aic = arq->io_context->aic;
+ aic = RQ_IOC(rq)->aic;
- if (arq->is_sync == REQ_SYNC && aic) {
+ if (rq_is_sync(rq) && aic) {
spin_lock(&aic->lock);
set_bit(AS_TASK_IORUNNING, &aic->state);
aic->last_end_request = jiffies;
spin_unlock(&aic->lock);
}
- put_io_context(arq->io_context);
-}
-
-/*
- * the back merge hash support functions
- */
-static const int as_hash_shift = 6;
-#define AS_HASH_BLOCK(sec) ((sec) >> 3)
-#define AS_HASH_FN(sec) (hash_long(AS_HASH_BLOCK((sec)), as_hash_shift))
-#define AS_HASH_ENTRIES (1 << as_hash_shift)
-#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors)
-#define list_entry_hash(ptr) list_entry((ptr), struct as_rq, hash)
-
-static inline void __as_del_arq_hash(struct as_rq *arq)
-{
- arq->on_hash = 0;
- list_del_init(&arq->hash);
-}
-
-static inline void as_del_arq_hash(struct as_rq *arq)
-{
- if (arq->on_hash)
- __as_del_arq_hash(arq);
-}
-
-static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq)
-{
- struct request *rq = arq->request;
-
- BUG_ON(arq->on_hash);
-
- arq->on_hash = 1;
- list_add(&arq->hash, &ad->hash[AS_HASH_FN(rq_hash_key(rq))]);
-}
-
-/*
- * move hot entry to front of chain
- */
-static inline void as_hot_arq_hash(struct as_data *ad, struct as_rq *arq)
-{
- struct request *rq = arq->request;
- struct list_head *head = &ad->hash[AS_HASH_FN(rq_hash_key(rq))];
-
- if (!arq->on_hash) {
- WARN_ON(1);
- return;
- }
-
- if (arq->hash.prev != head) {
- list_del(&arq->hash);
- list_add(&arq->hash, head);
- }
-}
-
-static struct request *as_find_arq_hash(struct as_data *ad, sector_t offset)
-{
- struct list_head *hash_list = &ad->hash[AS_HASH_FN(offset)];
- struct list_head *entry, *next = hash_list->next;
-
- while ((entry = next) != hash_list) {
- struct as_rq *arq = list_entry_hash(entry);
- struct request *__rq = arq->request;
-
- next = entry->next;
-
- BUG_ON(!arq->on_hash);
-
- if (!rq_mergeable(__rq)) {
- as_del_arq_hash(arq);
- continue;
- }
-
- if (rq_hash_key(__rq) == offset)
- return __rq;
- }
-
- return NULL;
+ put_io_context(RQ_IOC(rq));
}
/*
* rb tree support functions
*/
-#define RB_EMPTY(root) ((root)->rb_node == NULL)
-#define ON_RB(node) (rb_parent(node) != node)
-#define RB_CLEAR(node) (rb_set_parent(node, node))
-#define rb_entry_arq(node) rb_entry((node), struct as_rq, rb_node)
-#define ARQ_RB_ROOT(ad, arq) (&(ad)->sort_list[(arq)->is_sync])
-#define rq_rb_key(rq) (rq)->sector
-
-/*
- * as_find_first_arq 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 as_rq *as_find_first_arq(struct as_data *ad, int data_dir)
-{
- struct rb_node *n = ad->sort_list[data_dir].rb_node;
-
- if (n == NULL)
- return NULL;
-
- for (;;) {
- if (n->rb_left == NULL)
- return rb_entry_arq(n);
-
- n = n->rb_left;
- }
-}
-
-/*
- * Add the request to the rb tree if it is unique. If there is an alias (an
- * existing request against the same sector), which can happen when using
- * direct IO, then return the alias.
- */
-static struct as_rq *__as_add_arq_rb(struct as_data *ad, struct as_rq *arq)
-{
- struct rb_node **p = &ARQ_RB_ROOT(ad, arq)->rb_node;
- struct rb_node *parent = NULL;
- struct as_rq *__arq;
- struct request *rq = arq->request;
-
- arq->rb_key = rq_rb_key(rq);
-
- while (*p) {
- parent = *p;
- __arq = rb_entry_arq(parent);
-
- if (arq->rb_key < __arq->rb_key)
- p = &(*p)->rb_left;
- else if (arq->rb_key > __arq->rb_key)
- p = &(*p)->rb_right;
- else
- return __arq;
- }
-
- rb_link_node(&arq->rb_node, parent, p);
- rb_insert_color(&arq->rb_node, ARQ_RB_ROOT(ad, arq));
-
- return NULL;
-}
+#define RQ_RB_ROOT(ad, rq) (&(ad)->sort_list[rq_is_sync((rq))])
-static void as_add_arq_rb(struct as_data *ad, struct as_rq *arq)
+static void as_add_rq_rb(struct as_data *ad, struct request *rq)
{
- struct as_rq *alias;
+ struct request *alias;
- while ((unlikely(alias = __as_add_arq_rb(ad, arq)))) {
+ while ((unlikely(alias = elv_rb_add(RQ_RB_ROOT(ad, rq), rq)))) {
as_move_to_dispatch(ad, alias);
as_antic_stop(ad);
}
}
-static inline void as_del_arq_rb(struct as_data *ad, struct as_rq *arq)
-{
- if (!ON_RB(&arq->rb_node)) {
- WARN_ON(1);
- return;
- }
-
- rb_erase(&arq->rb_node, ARQ_RB_ROOT(ad, arq));
- RB_CLEAR(&arq->rb_node);
-}
-
-static struct request *
-as_find_arq_rb(struct as_data *ad, sector_t sector, int data_dir)
+static inline void as_del_rq_rb(struct as_data *ad, struct request *rq)
{
- struct rb_node *n = ad->sort_list[data_dir].rb_node;
- struct as_rq *arq;
-
- while (n) {
- arq = rb_entry_arq(n);
-
- if (sector < arq->rb_key)
- n = n->rb_left;
- else if (sector > arq->rb_key)
- n = n->rb_right;
- else
- return arq->request;
- }
-
- return NULL;
+ elv_rb_del(RQ_RB_ROOT(ad, rq), rq);
}
/*
* as_choose_req selects the preferred one of two requests of the same data_dir
* ignoring time - eg. timeouts, which is the job of as_dispatch_request
*/
-static struct as_rq *
-as_choose_req(struct as_data *ad, struct as_rq *arq1, struct as_rq *arq2)
+static struct request *
+as_choose_req(struct as_data *ad, struct request *rq1, struct request *rq2)
{
int data_dir;
sector_t last, s1, s2, d1, d2;
int r1_wrap=0, r2_wrap=0; /* requests are behind the disk head */
const sector_t maxback = MAXBACK;
- if (arq1 == NULL || arq1 == arq2)
- return arq2;
- if (arq2 == NULL)
- return arq1;
+ if (rq1 == NULL || rq1 == rq2)
+ return rq2;
+ if (rq2 == NULL)
+ return rq1;
- data_dir = arq1->is_sync;
+ data_dir = rq_is_sync(rq1);
last = ad->last_sector[data_dir];
- s1 = arq1->request->sector;
- s2 = arq2->request->sector;
+ s1 = rq1->sector;
+ s2 = rq2->sector;
- BUG_ON(data_dir != arq2->is_sync);
+ BUG_ON(data_dir != rq_is_sync(rq2));
/*
* Strict one way elevator _except_ in the case where we allow
/* Found required data */
if (!r1_wrap && r2_wrap)
- return arq1;
+ return rq1;
else if (!r2_wrap && r1_wrap)
- return arq2;
+ return rq2;
else if (r1_wrap && r2_wrap) {
/* both behind the head */
if (s1 <= s2)
- return arq1;
+ return rq1;
else
- return arq2;
+ return rq2;
}
/* Both requests in front of the head */
if (d1 < d2)
- return arq1;
+ return rq1;
else if (d2 < d1)
- return arq2;
+ return rq2;
else {
if (s1 >= s2)
- return arq1;
+ return rq1;
else
- return arq2;
+ return rq2;
}
}
/*
- * as_find_next_arq finds the next request after @prev in elevator order.
+ * as_find_next_rq finds the next request after @prev in elevator order.
* this with as_choose_req form the basis for how the scheduler chooses
* what request to process next. Anticipation works on top of this.
*/
-static struct as_rq *as_find_next_arq(struct as_data *ad, struct as_rq *last)
+static struct request *
+as_find_next_rq(struct as_data *ad, struct request *last)
{
- const int data_dir = last->is_sync;
- struct as_rq *ret;
struct rb_node *rbnext = rb_next(&last->rb_node);
struct rb_node *rbprev = rb_prev(&last->rb_node);
- struct as_rq *arq_next, *arq_prev;
+ struct request *next = NULL, *prev = NULL;
- BUG_ON(!ON_RB(&last->rb_node));
+ BUG_ON(RB_EMPTY_NODE(&last->rb_node));
if (rbprev)
- arq_prev = rb_entry_arq(rbprev);
- else
- arq_prev = NULL;
+ prev = rb_entry_rq(rbprev);
if (rbnext)
- arq_next = rb_entry_arq(rbnext);
+ next = rb_entry_rq(rbnext);
else {
- arq_next = as_find_first_arq(ad, data_dir);
- if (arq_next == last)
- arq_next = NULL;
- }
+ const int data_dir = rq_is_sync(last);
- ret = as_choose_req(ad, arq_next, arq_prev);
+ rbnext = rb_first(&ad->sort_list[data_dir]);
+ if (rbnext && rbnext != &last->rb_node)
+ next = rb_entry_rq(rbnext);
+ }
- return ret;
+ return as_choose_req(ad, next, prev);
}
/*
static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
struct request *rq)
{
- struct as_rq *arq = RQ_DATA(rq);
- int data_dir = arq->is_sync;
+ int data_dir = rq_is_sync(rq);
unsigned long thinktime = 0;
sector_t seek_dist;
* previous one issued.
*/
static int as_close_req(struct as_data *ad, struct as_io_context *aic,
- struct as_rq *arq)
+ struct request *rq)
{
unsigned long delay; /* milliseconds */
sector_t last = ad->last_sector[ad->batch_data_dir];
- sector_t next = arq->request->sector;
+ sector_t next = rq->sector;
sector_t delta; /* acceptable close offset (in sectors) */
sector_t s;
*
* If this task has queued some other IO, do not enter enticipation.
*/
-static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
+static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
{
struct io_context *ioc;
struct as_io_context *aic;
ioc = ad->io_context;
BUG_ON(!ioc);
- if (arq && ioc == arq->io_context) {
+ if (rq && ioc == RQ_IOC(rq)) {
/* request from same process */
return 1;
}
return 1;
}
- if (arq && arq->is_sync == REQ_SYNC && as_close_req(ad, aic, arq)) {
+ if (rq && rq_is_sync(rq) && as_close_req(ad, aic, rq)) {
/*
* Found a close request that is not one of ours.
*
ad->exit_no_coop = (7*ad->exit_no_coop)/8;
}
- as_update_iohist(ad, aic, arq->request);
+ as_update_iohist(ad, aic, rq);
return 1;
}
}
/*
- * as_can_anticipate indicates weather we should either run arq
+ * as_can_anticipate indicates whether we should either run rq
* or keep anticipating a better request.
*/
-static int as_can_anticipate(struct as_data *ad, struct as_rq *arq)
+static int as_can_anticipate(struct as_data *ad, struct request *rq)
{
if (!ad->io_context)
/*
*/
return 0;
- if (as_can_break_anticipation(ad, arq))
+ if (as_can_break_anticipation(ad, rq))
/*
* This request is a good candidate. Don't keep anticipating,
* run it.
}
/*
- * as_update_arq must be called whenever a request (arq) is added to
+ * as_update_rq must be called whenever a request (rq) is added to
* the sort_list. This function keeps caches up to date, and checks if the
* request might be one we are "anticipating"
*/
-static void as_update_arq(struct as_data *ad, struct as_rq *arq)
+static void as_update_rq(struct as_data *ad, struct request *rq)
{
- const int data_dir = arq->is_sync;
+ const int data_dir = rq_is_sync(rq);
- /* keep the next_arq cache up to date */
- ad->next_arq[data_dir] = as_choose_req(ad, arq, ad->next_arq[data_dir]);
+ /* keep the next_rq cache up to date */
+ ad->next_rq[data_dir] = as_choose_req(ad, rq, ad->next_rq[data_dir]);
/*
* have we been anticipating this request?
*/
if (ad->antic_status == ANTIC_WAIT_REQ
|| ad->antic_status == ANTIC_WAIT_NEXT) {
- if (as_can_break_anticipation(ad, arq))
+ if (as_can_break_anticipation(ad, rq))
as_antic_stop(ad);
}
}
static void as_completed_request(request_queue_t *q, struct request *rq)
{
struct as_data *ad = q->elevator->elevator_data;
- struct as_rq *arq = RQ_DATA(rq);
WARN_ON(!list_empty(&rq->queuelist));
- if (arq->state != AS_RQ_REMOVED) {
- printk("arq->state %d\n", arq->state);
+ if (RQ_STATE(rq) != AS_RQ_REMOVED) {
+ printk("rq->state %d\n", RQ_STATE(rq));
WARN_ON(1);
goto out;
}
* actually serviced. This should help devices with big TCQ windows
* and writeback caches
*/
- if (ad->new_batch && ad->batch_data_dir == arq->is_sync) {
+ if (ad->new_batch && ad->batch_data_dir == rq_is_sync(rq)) {
update_write_batch(ad);
ad->current_batch_expires = jiffies +
ad->batch_expire[REQ_SYNC];
ad->new_batch = 0;
}
- if (ad->io_context == arq->io_context && ad->io_context) {
+ if (ad->io_context == RQ_IOC(rq) && ad->io_context) {
ad->antic_start = jiffies;
ad->ioc_finished = 1;
if (ad->antic_status == ANTIC_WAIT_REQ) {
}
}
- as_put_io_context(arq);
+ as_put_io_context(rq);
out:
- arq->state = AS_RQ_POSTSCHED;
+ RQ_SET_STATE(rq, AS_RQ_POSTSCHED);
}
/*
*/
static void as_remove_queued_request(request_queue_t *q, struct request *rq)
{
- struct as_rq *arq = RQ_DATA(rq);
- const int data_dir = arq->is_sync;
+ const int data_dir = rq_is_sync(rq);
struct as_data *ad = q->elevator->elevator_data;
+ struct io_context *ioc;
- WARN_ON(arq->state != AS_RQ_QUEUED);
+ WARN_ON(RQ_STATE(rq) != AS_RQ_QUEUED);
- if (arq->io_context && arq->io_context->aic) {
- BUG_ON(!atomic_read(&arq->io_context->aic->nr_queued));
- atomic_dec(&arq->io_context->aic->nr_queued);
+ ioc = RQ_IOC(rq);
+ if (ioc && ioc->aic) {
+ BUG_ON(!atomic_read(&ioc->aic->nr_queued));
+ atomic_dec(&ioc->aic->nr_queued);
}
/*
- * Update the "next_arq" cache if we are about to remove its
+ * Update the "next_rq" cache if we are about to remove its
* entry
*/
- if (ad->next_arq[data_dir] == arq)
- ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
+ if (ad->next_rq[data_dir] == rq)
+ ad->next_rq[data_dir] = as_find_next_rq(ad, rq);
- list_del_init(&arq->fifo);
- as_del_arq_hash(arq);
- as_del_arq_rb(ad, arq);
+ rq_fifo_clear(rq);
+ as_del_rq_rb(ad, rq);
}
/*
*/
static int as_fifo_expired(struct as_data *ad, int adir)
{
- struct as_rq *arq;
+ struct request *rq;
long delta_jif;
delta_jif = jiffies - ad->last_check_fifo[adir];
if (list_empty(&ad->fifo_list[adir]))
return 0;
- arq = list_entry_fifo(ad->fifo_list[adir].next);
+ rq = rq_entry_fifo(ad->fifo_list[adir].next);
- return time_after(jiffies, arq->expires);
+ return time_after(jiffies, rq_fifo_time(rq));
}
/*
/*
* move an entry to dispatch queue
*/
-static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
+static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
{
- struct request *rq = arq->request;
- const int data_dir = arq->is_sync;
+ const int data_dir = rq_is_sync(rq);
- BUG_ON(!ON_RB(&arq->rb_node));
+ BUG_ON(RB_EMPTY_NODE(&rq->rb_node));
as_antic_stop(ad);
ad->antic_status = ANTIC_OFF;
/*
* This has to be set in order to be correctly updated by
- * as_find_next_arq
+ * as_find_next_rq
*/
ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
if (data_dir == REQ_SYNC) {
+ struct io_context *ioc = RQ_IOC(rq);
/* In case we have to anticipate after this */
- copy_io_context(&ad->io_context, &arq->io_context);
+ copy_io_context(&ad->io_context, &ioc);
} else {
if (ad->io_context) {
put_io_context(ad->io_context);
}
ad->ioc_finished = 0;
- ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
+ ad->next_rq[data_dir] = as_find_next_rq(ad, rq);
/*
* take it off the sort and fifo list, add to dispatch queue
*/
as_remove_queued_request(ad->q, rq);
- WARN_ON(arq->state != AS_RQ_QUEUED);
+ WARN_ON(RQ_STATE(rq) != AS_RQ_QUEUED);
elv_dispatch_sort(ad->q, rq);
- arq->state = AS_RQ_DISPATCHED;
- if (arq->io_context && arq->io_context->aic)
- atomic_inc(&arq->io_context->aic->nr_dispatched);
+ RQ_SET_STATE(rq, AS_RQ_DISPATCHED);
+ if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+ atomic_inc(&RQ_IOC(rq)->aic->nr_dispatched);
ad->nr_dispatched++;
}
static int as_dispatch_request(request_queue_t *q, int force)
{
struct as_data *ad = q->elevator->elevator_data;
- struct as_rq *arq;
const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
+ struct request *rq;
if (unlikely(force)) {
/*
ad->changed_batch = 0;
ad->new_batch = 0;
- while (ad->next_arq[REQ_SYNC]) {
- as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
+ while (ad->next_rq[REQ_SYNC]) {
+ as_move_to_dispatch(ad, ad->next_rq[REQ_SYNC]);
dispatched++;
}
ad->last_check_fifo[REQ_SYNC] = jiffies;
- while (ad->next_arq[REQ_ASYNC]) {
- as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
+ while (ad->next_rq[REQ_ASYNC]) {
+ as_move_to_dispatch(ad, ad->next_rq[REQ_ASYNC]);
dispatched++;
}
ad->last_check_fifo[REQ_ASYNC] = jiffies;
/*
* batch is still running or no reads or no writes
*/
- arq = ad->next_arq[ad->batch_data_dir];
+ rq = ad->next_rq[ad->batch_data_dir];
if (ad->batch_data_dir == REQ_SYNC && ad->antic_expire) {
if (as_fifo_expired(ad, REQ_SYNC))
goto fifo_expired;
- if (as_can_anticipate(ad, arq)) {
+ if (as_can_anticipate(ad, rq)) {
as_antic_waitreq(ad);
return 0;
}
}
- if (arq) {
+ if (rq) {
/* we have a "next request" */
if (reads && !writes)
ad->current_batch_expires =
*/
if (reads) {
- BUG_ON(RB_EMPTY(&ad->sort_list[REQ_SYNC]));
+ BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_SYNC]));
if (writes && ad->batch_data_dir == REQ_SYNC)
/*
ad->changed_batch = 1;
}
ad->batch_data_dir = REQ_SYNC;
- arq = list_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
+ rq = rq_entry_fifo(ad->fifo_list[REQ_SYNC].next);
ad->last_check_fifo[ad->batch_data_dir] = jiffies;
goto dispatch_request;
}
if (writes) {
dispatch_writes:
- BUG_ON(RB_EMPTY(&ad->sort_list[REQ_ASYNC]));
+ BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_ASYNC]));
if (ad->batch_data_dir == REQ_SYNC) {
ad->changed_batch = 1;
ad->batch_data_dir = REQ_ASYNC;
ad->current_write_count = ad->write_batch_count;
ad->write_batch_idled = 0;
- arq = ad->next_arq[ad->batch_data_dir];
+ rq = ad->next_rq[ad->batch_data_dir];
goto dispatch_request;
}
if (as_fifo_expired(ad, ad->batch_data_dir)) {
fifo_expired:
- arq = list_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
- BUG_ON(arq == NULL);
+ rq = rq_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
}
if (ad->changed_batch) {
}
/*
- * arq is the selected appropriate request.
+ * rq is the selected appropriate request.
*/
- as_move_to_dispatch(ad, arq);
+ as_move_to_dispatch(ad, rq);
return 1;
}
/*
- * add arq to rbtree and fifo
+ * add rq to rbtree and fifo
*/
static void as_add_request(request_queue_t *q, struct request *rq)
{
struct as_data *ad = q->elevator->elevator_data;
- struct as_rq *arq = RQ_DATA(rq);
int data_dir;
- arq->state = AS_RQ_NEW;
+ RQ_SET_STATE(rq, AS_RQ_NEW);
- if (rq_data_dir(arq->request) == READ
- || current->flags&PF_SYNCWRITE)
- arq->is_sync = 1;
- else
- arq->is_sync = 0;
- data_dir = arq->is_sync;
+ data_dir = rq_is_sync(rq);
- arq->io_context = as_get_io_context();
+ rq->elevator_private = as_get_io_context(q->node);
- if (arq->io_context) {
- as_update_iohist(ad, arq->io_context->aic, arq->request);
- atomic_inc(&arq->io_context->aic->nr_queued);
+ if (RQ_IOC(rq)) {
+ as_update_iohist(ad, RQ_IOC(rq)->aic, rq);
+ atomic_inc(&RQ_IOC(rq)->aic->nr_queued);
}
- as_add_arq_rb(ad, arq);
- if (rq_mergeable(arq->request))
- as_add_arq_hash(ad, arq);
+ as_add_rq_rb(ad, rq);
/*
* set expire time (only used for reads) and add to fifo list
*/
- arq->expires = jiffies + ad->fifo_expire[data_dir];
- list_add_tail(&arq->fifo, &ad->fifo_list[data_dir]);
+ rq_set_fifo_time(rq, jiffies + ad->fifo_expire[data_dir]);
+ list_add_tail(&rq->queuelist, &ad->fifo_list[data_dir]);
- as_update_arq(ad, arq); /* keep state machine up to date */
- arq->state = AS_RQ_QUEUED;
+ as_update_rq(ad, rq); /* keep state machine up to date */
+ RQ_SET_STATE(rq, AS_RQ_QUEUED);
}
static void as_activate_request(request_queue_t *q, struct request *rq)
{
- struct as_rq *arq = RQ_DATA(rq);
-
- WARN_ON(arq->state != AS_RQ_DISPATCHED);
- arq->state = AS_RQ_REMOVED;
- if (arq->io_context && arq->io_context->aic)
- atomic_dec(&arq->io_context->aic->nr_dispatched);
+ WARN_ON(RQ_STATE(rq) != AS_RQ_DISPATCHED);
+ RQ_SET_STATE(rq, AS_RQ_REMOVED);
+ if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+ atomic_dec(&RQ_IOC(rq)->aic->nr_dispatched);
}
static void as_deactivate_request(request_queue_t *q, struct request *rq)
{
- struct as_rq *arq = RQ_DATA(rq);
-
- WARN_ON(arq->state != AS_RQ_REMOVED);
- arq->state = AS_RQ_DISPATCHED;
- if (arq->io_context && arq->io_context->aic)
- atomic_inc(&arq->io_context->aic->nr_dispatched);
+ WARN_ON(RQ_STATE(rq) != AS_RQ_REMOVED);
+ RQ_SET_STATE(rq, AS_RQ_DISPATCHED);
+ if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+ atomic_inc(&RQ_IOC(rq)->aic->nr_dispatched);
}
/*
&& list_empty(&ad->fifo_list[REQ_SYNC]);
}
-static struct request *as_former_request(request_queue_t *q,
- struct request *rq)
-{
- struct as_rq *arq = RQ_DATA(rq);
- struct rb_node *rbprev = rb_prev(&arq->rb_node);
- struct request *ret = NULL;
-
- if (rbprev)
- ret = rb_entry_arq(rbprev)->request;
-
- return ret;
-}
-
-static struct request *as_latter_request(request_queue_t *q,
- struct request *rq)
-{
- struct as_rq *arq = RQ_DATA(rq);
- struct rb_node *rbnext = rb_next(&arq->rb_node);
- struct request *ret = NULL;
-
- if (rbnext)
- ret = rb_entry_arq(rbnext)->request;
-
- return ret;
-}
-
static int
as_merge(request_queue_t *q, struct request **req, struct bio *bio)
{
struct as_data *ad = q->elevator->elevator_data;
sector_t rb_key = bio->bi_sector + bio_sectors(bio);
struct request *__rq;
- int ret;
-
- /*
- * see if the merge hash can satisfy a back merge
- */
- __rq = as_find_arq_hash(ad, 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
*/
- __rq = as_find_arq_rb(ad, 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;
- }
+ __rq = elv_rb_find(&ad->sort_list[bio_data_dir(bio)], rb_key);
+ if (__rq && elv_rq_merge_ok(__rq, bio)) {
+ *req = __rq;
+ return ELEVATOR_FRONT_MERGE;
}
return ELEVATOR_NO_MERGE;
-out:
- if (ret) {
- if (rq_mergeable(__rq))
- as_hot_arq_hash(ad, RQ_DATA(__rq));
- }
- *req = __rq;
- return ret;
}
-static void as_merged_request(request_queue_t *q, struct request *req)
+static void as_merged_request(request_queue_t *q, struct request *req, int type)
{
struct as_data *ad = q->elevator->elevator_data;
- struct as_rq *arq = RQ_DATA(req);
-
- /*
- * hash always needs to be repositioned, key is end sector
- */
- as_del_arq_hash(arq);
- as_add_arq_hash(ad, arq);
/*
* if the merge was a front merge, we need to reposition request
*/
- if (rq_rb_key(req) != arq->rb_key) {
- as_del_arq_rb(ad, arq);
- as_add_arq_rb(ad, arq);
+ if (type == ELEVATOR_FRONT_MERGE) {
+ as_del_rq_rb(ad, req);
+ as_add_rq_rb(ad, req);
/*
* Note! At this stage of this and the next function, our next
* request may not be optimal - eg the request may have "grown"
static void as_merged_requests(request_queue_t *q, struct request *req,
struct request *next)
{
- struct as_data *ad = q->elevator->elevator_data;
- struct as_rq *arq = RQ_DATA(req);
- struct as_rq *anext = RQ_DATA(next);
-
- BUG_ON(!arq);
- BUG_ON(!anext);
-
/*
- * reposition arq (this is the merged request) in hash, and in rbtree
- * in case of a front merge
+ * if next expires before rq, assign its expire time to arq
+ * and move into next position (next will be deleted) in fifo
*/
- as_del_arq_hash(arq);
- as_add_arq_hash(ad, arq);
-
- if (rq_rb_key(req) != arq->rb_key) {
- as_del_arq_rb(ad, arq);
- as_add_arq_rb(ad, arq);
- }
+ if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
+ if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
+ struct io_context *rioc = RQ_IOC(req);
+ struct io_context *nioc = RQ_IOC(next);
- /*
- * if anext expires before arq, assign its expire time to arq
- * and move into anext position (anext will be deleted) in fifo
- */
- if (!list_empty(&arq->fifo) && !list_empty(&anext->fifo)) {
- if (time_before(anext->expires, arq->expires)) {
- list_move(&arq->fifo, &anext->fifo);
- arq->expires = anext->expires;
+ list_move(&req->queuelist, &next->queuelist);
+ rq_set_fifo_time(req, rq_fifo_time(next));
/*
* Don't copy here but swap, because when anext is
* removed below, it must contain the unused context
*/
- swap_io_context(&arq->io_context, &anext->io_context);
+ swap_io_context(&rioc, &nioc);
}
}
* kill knowledge of next, this one is a goner
*/
as_remove_queued_request(q, next);
- as_put_io_context(anext);
+ as_put_io_context(next);
- anext->state = AS_RQ_MERGED;
+ RQ_SET_STATE(next, AS_RQ_MERGED);
}
/*
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
- if (!as_queue_empty(q))
- q->request_fn(q);
+ blk_start_queueing(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
-static void as_put_request(request_queue_t *q, struct request *rq)
-{
- struct as_data *ad = q->elevator->elevator_data;
- struct as_rq *arq = RQ_DATA(rq);
-
- if (!arq) {
- WARN_ON(1);
- return;
- }
-
- if (unlikely(arq->state != AS_RQ_POSTSCHED &&
- arq->state != AS_RQ_PRESCHED &&
- arq->state != AS_RQ_MERGED)) {
- printk("arq->state %d\n", arq->state);
- WARN_ON(1);
- }
-
- mempool_free(arq, ad->arq_pool);
- rq->elevator_private = NULL;
-}
-
-static int as_set_request(request_queue_t *q, struct request *rq,
- struct bio *bio, gfp_t gfp_mask)
-{
- struct as_data *ad = q->elevator->elevator_data;
- struct as_rq *arq = mempool_alloc(ad->arq_pool, gfp_mask);
-
- if (arq) {
- memset(arq, 0, sizeof(*arq));
- RB_CLEAR(&arq->rb_node);
- arq->request = rq;
- arq->state = AS_RQ_PRESCHED;
- arq->io_context = NULL;
- INIT_LIST_HEAD(&arq->hash);
- arq->on_hash = 0;
- INIT_LIST_HEAD(&arq->fifo);
- rq->elevator_private = arq;
- return 0;
- }
-
- return 1;
-}
-
-static int as_may_queue(request_queue_t *q, int rw, struct bio *bio)
+static int as_may_queue(request_queue_t *q, int rw)
{
int ret = ELV_MQUEUE_MAY;
struct as_data *ad = q->elevator->elevator_data;
struct io_context *ioc;
if (ad->antic_status == ANTIC_WAIT_REQ ||
ad->antic_status == ANTIC_WAIT_NEXT) {
- ioc = as_get_io_context();
+ ioc = as_get_io_context(q->node);
if (ad->io_context == ioc)
ret = ELV_MQUEUE_MUST;
put_io_context(ioc);
BUG_ON(!list_empty(&ad->fifo_list[REQ_SYNC]));
BUG_ON(!list_empty(&ad->fifo_list[REQ_ASYNC]));
- mempool_destroy(ad->arq_pool);
put_io_context(ad->io_context);
- kfree(ad->hash);
kfree(ad);
}
/*
- * initialize elevator private data (as_data), and alloc a arq for
- * each request on the free lists
+ * initialize elevator private data (as_data).
*/
static void *as_init_queue(request_queue_t *q, elevator_t *e)
{
struct as_data *ad;
- int i;
-
- if (!arq_pool)
- return NULL;
ad = kmalloc_node(sizeof(*ad), GFP_KERNEL, q->node);
if (!ad)
ad->q = q; /* Identify what queue the data belongs to */
- ad->hash = kmalloc_node(sizeof(struct list_head)*AS_HASH_ENTRIES,
- GFP_KERNEL, q->node);
- if (!ad->hash) {
- kfree(ad);
- return NULL;
- }
-
- ad->arq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
- mempool_free_slab, arq_pool, q->node);
- if (!ad->arq_pool) {
- kfree(ad->hash);
- kfree(ad);
- return NULL;
- }
-
/* anticipatory scheduling helpers */
ad->antic_timer.function = as_antic_timeout;
ad->antic_timer.data = (unsigned long)q;
init_timer(&ad->antic_timer);
INIT_WORK(&ad->antic_work, as_work_handler, q);
- for (i = 0; i < AS_HASH_ENTRIES; i++)
- INIT_LIST_HEAD(&ad->hash[i]);
-
INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]);
INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
ad->sort_list[REQ_SYNC] = RB_ROOT;
.elevator_deactivate_req_fn = as_deactivate_request,
.elevator_queue_empty_fn = as_queue_empty,
.elevator_completed_req_fn = as_completed_request,
- .elevator_former_req_fn = as_former_request,
- .elevator_latter_req_fn = as_latter_request,
- .elevator_set_req_fn = as_set_request,
- .elevator_put_req_fn = as_put_request,
+ .elevator_former_req_fn = elv_rb_former_request,
+ .elevator_latter_req_fn = elv_rb_latter_request,
.elevator_may_queue_fn = as_may_queue,
.elevator_init_fn = as_init_queue,
.elevator_exit_fn = as_exit_queue,
{
int ret;
- arq_pool = kmem_cache_create("as_arq", sizeof(struct as_rq),
- 0, 0, NULL, NULL);
- if (!arq_pool)
- return -ENOMEM;
-
ret = elv_register(&iosched_as);
if (!ret) {
/*
return 0;
}
- kmem_cache_destroy(arq_pool);
return ret;
}
static void __exit as_exit(void)
{
- DECLARE_COMPLETION(all_gone);
+ DECLARE_COMPLETION_ONSTACK(all_gone);
elv_unregister(&iosched_as);
ioc_gone = &all_gone;
/* ioc_gone's update must be visible before reading ioc_count */
smp_wmb();
- if (atomic_read(&ioc_count))
+ if (elv_ioc_count_read(ioc_count))
wait_for_completion(ioc_gone);
synchronize_rcu();
- kmem_cache_destroy(arq_pool);
}
module_init(as_init);
git.openpandora.org / pandora-kernel.git / blobdiff