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 */
unsigned long exit_prob; /* probability a task will exit while
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 */
AS_RQ_POSTSCHED, /* when they shouldn't be */
};
-struct as_rq {
- struct request *request;
-
- struct io_context *io_context; /* The submitting task */
-
- enum arq_state state;
-};
-
-#define RQ_DATA(rq) ((struct as_rq *) (rq)->elevator_private)
-
-static kmem_cache_t *arq_pool;
+#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)
static atomic_t ioc_count = ATOMIC_INIT(0);
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);
/*
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 (rq_is_sync(arq->request) && 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);
+ put_io_context(RQ_IOC(rq));
}
/*
*/
#define RQ_RB_ROOT(ad, rq) (&(ad)->sort_list[rq_is_sync((rq))])
-static void as_add_arq_rb(struct as_data *ad, struct request *rq)
+static void as_add_rq_rb(struct as_data *ad, struct request *rq)
{
struct request *alias;
while ((unlikely(alias = elv_rb_add(RQ_RB_ROOT(ad, rq), rq)))) {
- as_move_to_dispatch(ad, RQ_DATA(alias));
+ as_move_to_dispatch(ad, alias);
as_antic_stop(ad);
}
}
-static inline void as_del_arq_rb(struct as_data *ad, struct request *rq)
+static inline void as_del_rq_rb(struct as_data *ad, struct request *rq)
{
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 = rq_is_sync(arq1->request);
+ 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 != rq_is_sync(arq2->request));
+ 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 *arq)
+static struct request *
+as_find_next_rq(struct as_data *ad, struct request *last)
{
- struct request *last = arq->request;
struct rb_node *rbnext = rb_next(&last->rb_node);
struct rb_node *rbprev = rb_prev(&last->rb_node);
- struct as_rq *next = NULL, *prev = NULL;
+ struct request *next = NULL, *prev = NULL;
BUG_ON(RB_EMPTY_NODE(&last->rb_node));
if (rbprev)
- prev = RQ_DATA(rb_entry_rq(rbprev));
+ prev = rb_entry_rq(rbprev);
if (rbnext)
- next = RQ_DATA(rb_entry_rq(rbnext));
+ next = rb_entry_rq(rbnext);
else {
const int data_dir = rq_is_sync(last);
rbnext = rb_first(&ad->sort_list[data_dir]);
if (rbnext && rbnext != &last->rb_node)
- next = RQ_DATA(rb_entry_rq(rbnext));
+ next = rb_entry_rq(rbnext);
}
return as_choose_req(ad, next, prev);
* 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 && rq_is_sync(arq->request) && 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 whether 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 = rq_is_sync(arq->request);
+ 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;
}
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 = 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);
rq_fifo_clear(rq);
- as_del_arq_rb(ad, rq);
+ as_del_rq_rb(ad, 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 = rq_is_sync(rq);
BUG_ON(RB_EMPTY_NODE(&rq->rb_node));
/*
* 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 =
ad->changed_batch = 1;
}
ad->batch_data_dir = REQ_SYNC;
- arq = RQ_DATA(rq_entry_fifo(ad->fifo_list[REQ_SYNC].next));
+ rq = rq_entry_fifo(ad->fifo_list[REQ_SYNC].next);
ad->last_check_fifo[ad->batch_data_dir] = jiffies;
goto dispatch_request;
}
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 = RQ_DATA(rq_entry_fifo(ad->fifo_list[ad->batch_data_dir].next));
+ 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);
data_dir = rq_is_sync(rq);
- arq->io_context = as_get_io_context();
+ rq->elevator_private = as_get_io_context();
- 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, rq);
+ as_add_rq_rb(ad, rq);
/*
* set expire time (only used for reads) and add to fifo list
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);
}
/*
* if the merge was a front merge, we need to reposition request
*/
if (type == ELEVATOR_FRONT_MERGE) {
- as_del_arq_rb(ad, req);
- as_add_arq_rb(ad, req);
+ 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_rq *arq = RQ_DATA(req);
- struct as_rq *anext = RQ_DATA(next);
-
- BUG_ON(!arq);
- BUG_ON(!anext);
-
/*
- * if anext expires before arq, assign its expire time to arq
- * and move into anext position (anext will be deleted) in fifo
+ * if next expires before rq, assign its expire time to arq
+ * and move into next position (next will be deleted) in fifo
*/
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);
+
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);
}
/*
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));
- arq->request = rq;
- arq->state = AS_RQ_PRESCHED;
- arq->io_context = NULL;
- rq->elevator_private = arq;
- return 0;
- }
-
- return 1;
-}
-
static int as_may_queue(request_queue_t *q, int rw, struct bio *bio)
{
int ret = ELV_MQUEUE_MAY;
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);
}
/*
- * 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;
- if (!arq_pool)
- return NULL;
-
ad = kmalloc_node(sizeof(*ad), GFP_KERNEL, q->node);
if (!ad)
return NULL;
ad->q = q; /* Identify what queue the data belongs to */
- 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);
- return NULL;
- }
-
/* anticipatory scheduling helpers */
ad->antic_timer.function = as_antic_timeout;
ad->antic_timer.data = (unsigned long)q;
.elevator_completed_req_fn = as_completed_request,
.elevator_former_req_fn = elv_rb_former_request,
.elevator_latter_req_fn = elv_rb_latter_request,
- .elevator_set_req_fn = as_set_request,
- .elevator_put_req_fn = as_put_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;
}
if (atomic_read(&ioc_count))
wait_for_completion(ioc_gone);
synchronize_rcu();
- kmem_cache_destroy(arq_pool);
}
module_init(as_init);
projects / kernel / kernel-generic.git / commitdiff