struct as_rq *next_arq[2]; /* next in sort order */
sector_t last_sector[2]; /* last REQ_SYNC & REQ_ASYNC sectors */
- struct list_head *dispatch; /* driver dispatch queue */
struct list_head *hash; /* request hash */
unsigned long exit_prob; /* probability a task will exit while
return ioc;
}
+static void as_put_io_context(struct as_rq *arq)
+{
+ struct as_io_context *aic;
+
+ if (unlikely(!arq->io_context))
+ return;
+
+ aic = arq->io_context->aic;
+
+ if (arq->is_sync == REQ_SYNC && 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
*/
__as_del_arq_hash(arq);
}
-static void as_remove_merge_hints(request_queue_t *q, struct as_rq *arq)
-{
- as_del_arq_hash(arq);
-
- if (q->last_merge == arq->request)
- q->last_merge = NULL;
-}
-
static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq)
{
struct request *rq = arq->request;
BUG_ON(!arq->on_hash);
if (!rq_mergeable(__rq)) {
- as_remove_merge_hints(ad->q, arq);
+ as_del_arq_hash(arq);
continue;
}
WARN_ON(!list_empty(&rq->queuelist));
- if (arq->state == AS_RQ_PRESCHED) {
- WARN_ON(arq->io_context);
- goto out;
- }
-
- if (arq->state == AS_RQ_MERGED)
- goto out_ioc;
-
if (arq->state != AS_RQ_REMOVED) {
printk("arq->state %d\n", arq->state);
WARN_ON(1);
goto out;
}
- if (!blk_fs_request(rq))
- goto out;
-
if (ad->changed_batch && ad->nr_dispatched == 1) {
kblockd_schedule_work(&ad->antic_work);
ad->changed_batch = 0;
}
}
-out_ioc:
- if (!arq->io_context)
- goto out;
-
- if (arq->is_sync == REQ_SYNC) {
- struct as_io_context *aic = arq->io_context->aic;
- if (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);
+ as_put_io_context(arq);
out:
arq->state = AS_RQ_POSTSCHED;
}
ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
list_del_init(&arq->fifo);
- as_remove_merge_hints(q, arq);
+ as_del_arq_hash(arq);
as_del_arq_rb(ad, arq);
}
-/*
- * as_remove_dispatched_request is called to remove a request which has gone
- * to the dispatch list.
- */
-static void as_remove_dispatched_request(request_queue_t *q, struct request *rq)
-{
- struct as_rq *arq = RQ_DATA(rq);
- struct as_io_context *aic;
-
- if (!arq) {
- WARN_ON(1);
- return;
- }
-
- WARN_ON(arq->state != AS_RQ_DISPATCHED);
- WARN_ON(ON_RB(&arq->rb_node));
- if (arq->io_context && arq->io_context->aic) {
- aic = arq->io_context->aic;
- if (aic) {
- WARN_ON(!atomic_read(&aic->nr_dispatched));
- atomic_dec(&aic->nr_dispatched);
- }
- }
-}
-
-/*
- * as_remove_request is called when a driver has finished with a request.
- * This should be only called for dispatched requests, but for some reason
- * a POWER4 box running hwscan it does not.
- */
-static void as_remove_request(request_queue_t *q, struct request *rq)
-{
- struct as_rq *arq = RQ_DATA(rq);
-
- if (unlikely(arq->state == AS_RQ_NEW))
- goto out;
-
- if (ON_RB(&arq->rb_node)) {
- if (arq->state != AS_RQ_QUEUED) {
- printk("arq->state %d\n", arq->state);
- WARN_ON(1);
- goto out;
- }
- /*
- * We'll lose the aliased request(s) here. I don't think this
- * will ever happen, but if it does, hopefully someone will
- * report it.
- */
- WARN_ON(!list_empty(&rq->queuelist));
- as_remove_queued_request(q, rq);
- } else {
- if (arq->state != AS_RQ_DISPATCHED) {
- printk("arq->state %d\n", arq->state);
- WARN_ON(1);
- goto out;
- }
- as_remove_dispatched_request(q, rq);
- }
-out:
- arq->state = AS_RQ_REMOVED;
-}
-
/*
* as_fifo_expired returns 0 if there are no expired reads on the fifo,
* 1 otherwise. It is ratelimited so that we only perform the check once per
static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
{
struct request *rq = arq->request;
- struct list_head *insert;
const int data_dir = arq->is_sync;
BUG_ON(!ON_RB(&arq->rb_node));
/*
* take it off the sort and fifo list, add to dispatch queue
*/
- insert = ad->dispatch->prev;
-
while (!list_empty(&rq->queuelist)) {
struct request *__rq = list_entry_rq(rq->queuelist.next);
struct as_rq *__arq = RQ_DATA(__rq);
- list_move_tail(&__rq->queuelist, ad->dispatch);
+ list_del(&__rq->queuelist);
+
+ elv_dispatch_add_tail(ad->q, __rq);
if (__arq->io_context && __arq->io_context->aic)
atomic_inc(&__arq->io_context->aic->nr_dispatched);
as_remove_queued_request(ad->q, rq);
WARN_ON(arq->state != AS_RQ_QUEUED);
- list_add(&rq->queuelist, insert);
+ 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);
* read/write expire, batch expire, etc, and moves it to the dispatch
* queue. Returns 1 if a request was found, 0 otherwise.
*/
-static int as_dispatch_request(struct as_data *ad)
+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]);
+ if (unlikely(force)) {
+ /*
+ * Forced dispatch, accounting is useless. Reset
+ * accounting states and dump fifo_lists. Note that
+ * batch_data_dir is reset to REQ_SYNC to avoid
+ * screwing write batch accounting as write batch
+ * accounting occurs on W->R transition.
+ */
+ int dispatched = 0;
+
+ ad->batch_data_dir = REQ_SYNC;
+ ad->changed_batch = 0;
+ ad->new_batch = 0;
+
+ while (ad->next_arq[REQ_SYNC]) {
+ as_move_to_dispatch(ad, ad->next_arq[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]);
+ dispatched++;
+ }
+ ad->last_check_fifo[REQ_ASYNC] = jiffies;
+
+ return dispatched;
+ }
+
/* Signal that the write batch was uncontended, so we can't time it */
if (ad->batch_data_dir == REQ_ASYNC && !reads) {
if (ad->current_write_count == 0 || !writes)
return 1;
}
-static struct request *as_next_request(request_queue_t *q)
-{
- struct as_data *ad = q->elevator->elevator_data;
- struct request *rq = NULL;
-
- /*
- * if there are still requests on the dispatch queue, grab the first
- */
- if (!list_empty(ad->dispatch) || as_dispatch_request(ad))
- rq = list_entry_rq(ad->dispatch->next);
-
- return rq;
-}
-
/*
* Add arq to a list behind alias
*/
/*
* Don't want to have to handle merges.
*/
- as_remove_merge_hints(ad->q, arq);
+ as_del_arq_hash(arq);
}
/*
* add arq to rbtree and fifo
*/
-static void as_add_request(struct as_data *ad, struct as_rq *arq)
+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);
struct as_rq *alias;
int data_dir;
+ if (arq->state != AS_RQ_PRESCHED) {
+ printk("arq->state: %d\n", arq->state);
+ WARN_ON(1);
+ }
+ arq->state = AS_RQ_NEW;
+
if (rq_data_dir(arq->request) == READ
|| current->flags&PF_SYNCWRITE)
arq->is_sync = 1;
arq->expires = jiffies + ad->fifo_expire[data_dir];
list_add_tail(&arq->fifo, &ad->fifo_list[data_dir]);
- if (rq_mergeable(arq->request)) {
+ if (rq_mergeable(arq->request))
as_add_arq_hash(ad, arq);
-
- if (!ad->q->last_merge)
- ad->q->last_merge = arq->request;
- }
as_update_arq(ad, arq); /* keep state machine up to date */
} else {
arq->state = AS_RQ_QUEUED;
}
-static void as_deactivate_request(request_queue_t *q, struct request *rq)
+static void as_activate_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) {
- if (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);
- }
- } else
- WARN_ON(blk_fs_request(rq)
- && (!(rq->flags & (REQ_HARDBARRIER|REQ_SOFTBARRIER))) );
-
- /* Stop anticipating - let this request get through */
- as_antic_stop(ad);
-}
-
-/*
- * requeue the request. The request has not been completed, nor is it a
- * new request, so don't touch accounting.
- */
-static void as_requeue_request(request_queue_t *q, struct request *rq)
-{
- as_deactivate_request(q, rq);
- list_add(&rq->queuelist, &q->queue_head);
-}
-
-/*
- * Account a request that is inserted directly onto the dispatch queue.
- * arq->io_context->aic->nr_dispatched should not need to be incremented
- * because only new requests should come through here: requeues go through
- * our explicit requeue handler.
- */
-static void as_account_queued_request(struct as_data *ad, struct request *rq)
-{
- if (blk_fs_request(rq)) {
- struct as_rq *arq = RQ_DATA(rq);
- arq->state = AS_RQ_DISPATCHED;
- ad->nr_dispatched++;
- }
+ 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);
}
-static void
-as_insert_request(request_queue_t *q, struct request *rq, int where)
+static void as_deactivate_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) {
- if (arq->state != AS_RQ_PRESCHED) {
- printk("arq->state: %d\n", arq->state);
- WARN_ON(1);
- }
- arq->state = AS_RQ_NEW;
- }
-
- /* barriers must flush the reorder queue */
- if (unlikely(rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)
- && where == ELEVATOR_INSERT_SORT)) {
- WARN_ON(1);
- where = ELEVATOR_INSERT_BACK;
- }
-
- switch (where) {
- case ELEVATOR_INSERT_BACK:
- while (ad->next_arq[REQ_SYNC])
- as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
-
- while (ad->next_arq[REQ_ASYNC])
- as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
-
- list_add_tail(&rq->queuelist, ad->dispatch);
- as_account_queued_request(ad, rq);
- as_antic_stop(ad);
- break;
- case ELEVATOR_INSERT_FRONT:
- list_add(&rq->queuelist, ad->dispatch);
- as_account_queued_request(ad, rq);
- as_antic_stop(ad);
- break;
- case ELEVATOR_INSERT_SORT:
- BUG_ON(!blk_fs_request(rq));
- as_add_request(ad, arq);
- break;
- default:
- BUG();
- return;
- }
+ 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);
}
/*
{
struct as_data *ad = q->elevator->elevator_data;
- if (!list_empty(&ad->fifo_list[REQ_ASYNC])
- || !list_empty(&ad->fifo_list[REQ_SYNC])
- || !list_empty(ad->dispatch))
- return 0;
-
- return 1;
+ return list_empty(&ad->fifo_list[REQ_ASYNC])
+ && list_empty(&ad->fifo_list[REQ_SYNC]);
}
static struct request *
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
*/
return ELEVATOR_NO_MERGE;
out:
- if (rq_mergeable(__rq))
- q->last_merge = __rq;
-out_insert:
if (ret) {
if (rq_mergeable(__rq))
as_hot_arq_hash(ad, RQ_DATA(__rq));
* behind the disk head. We currently don't bother adjusting.
*/
}
-
- if (arq->on_hash)
- q->last_merge = req;
}
static void
* kill knowledge of next, this one is a goner
*/
as_remove_queued_request(q, next);
+ as_put_io_context(anext);
anext->state = AS_RQ_MERGED;
}
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
- if (as_next_request(q))
+ if (!as_queue_empty(q))
q->request_fn(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
return;
}
- if (arq->state != AS_RQ_POSTSCHED && arq->state != AS_RQ_PRESCHED) {
+ 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);
}
}
static int as_set_request(request_queue_t *q, struct request *rq,
- struct bio *bio, int gfp_mask)
+ 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);
INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
ad->sort_list[REQ_SYNC] = RB_ROOT;
ad->sort_list[REQ_ASYNC] = RB_ROOT;
- ad->dispatch = &q->queue_head;
ad->fifo_expire[REQ_SYNC] = default_read_expire;
ad->fifo_expire[REQ_ASYNC] = default_write_expire;
ad->antic_expire = default_antic_expire;
static ssize_t
as_var_show(unsigned int var, char *page)
{
- var = (var * 1000) / HZ;
return sprintf(page, "%d\n", var);
}
static ssize_t
as_var_store(unsigned long *var, const char *page, size_t count)
{
- unsigned long tmp;
char *p = (char *) page;
- tmp = simple_strtoul(p, &p, 10);
- if (tmp != 0) {
- tmp = (tmp * HZ) / 1000;
- if (tmp == 0)
- tmp = 1;
- }
- *var = tmp;
+ *var = simple_strtoul(p, &p, 10);
return count;
}
.elevator_merge_fn = as_merge,
.elevator_merged_fn = as_merged_request,
.elevator_merge_req_fn = as_merged_requests,
- .elevator_next_req_fn = as_next_request,
- .elevator_add_req_fn = as_insert_request,
- .elevator_remove_req_fn = as_remove_request,
- .elevator_requeue_req_fn = as_requeue_request,
+ .elevator_dispatch_fn = as_dispatch_request,
+ .elevator_add_req_fn = as_add_request,
+ .elevator_activate_req_fn = as_activate_request,
.elevator_deactivate_req_fn = as_deactivate_request,
.elevator_queue_empty_fn = as_queue_empty,
.elevator_completed_req_fn = as_completed_request,
projects / linux-2.6-omap-h63xx.git / blobdiff