diff options
| -rw-r--r-- | block/as-iosched.c | 144 |
1 files changed, 25 insertions, 119 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c index 43fa204..8da3cf6 100644 --- a/block/as-iosched.c +++ b/block/as-iosched.c @@ -182,6 +182,9 @@ struct as_rq { static kmem_cache_t *arq_pool; +static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq); +static void as_antic_stop(struct as_data *ad); + /* * IO Context helper functions */ @@ -370,7 +373,7 @@ static struct as_rq *as_find_first_arq(struct as_data *ad, int data_dir) * 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) +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; @@ -397,6 +400,16 @@ static struct as_rq *as_add_arq_rb(struct as_data *ad, struct as_rq *arq) return NULL; } +static void as_add_arq_rb(struct as_data *ad, struct as_rq *arq) +{ + struct as_rq *alias; + + while ((unlikely(alias = __as_add_arq_rb(ad, arq)))) { + 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)) { @@ -1133,23 +1146,6 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq) /* * take it off the sort and fifo list, add to dispatch queue */ - while (!list_empty(&rq->queuelist)) { - struct request *__rq = list_entry_rq(rq->queuelist.next); - struct as_rq *__arq = RQ_DATA(__rq); - - 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); - - WARN_ON(__arq->state != AS_RQ_QUEUED); - __arq->state = AS_RQ_DISPATCHED; - - ad->nr_dispatched++; - } - as_remove_queued_request(ad->q, rq); WARN_ON(arq->state != AS_RQ_QUEUED); @@ -1326,49 +1322,12 @@ fifo_expired: } /* - * Add arq to a list behind alias - */ -static inline void -as_add_aliased_request(struct as_data *ad, struct as_rq *arq, - struct as_rq *alias) -{ - struct request *req = arq->request; - struct list_head *insert = alias->request->queuelist.prev; - - /* - * Transfer list of aliases - */ - while (!list_empty(&req->queuelist)) { - struct request *__rq = list_entry_rq(req->queuelist.next); - struct as_rq *__arq = RQ_DATA(__rq); - - list_move_tail(&__rq->queuelist, &alias->request->queuelist); - - WARN_ON(__arq->state != AS_RQ_QUEUED); - } - - /* - * Another request with the same start sector on the rbtree. - * Link this request to that sector. They are untangled in - * as_move_to_dispatch - */ - list_add(&arq->request->queuelist, insert); - - /* - * Don't want to have to handle merges. - */ - as_del_arq_hash(arq); - arq->request->flags |= REQ_NOMERGE; -} - -/* * add arq 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); - struct as_rq *alias; int data_dir; arq->state = AS_RQ_NEW; @@ -1387,33 +1346,17 @@ static void as_add_request(request_queue_t *q, struct request *rq) atomic_inc(&arq->io_context->aic->nr_queued); } - alias = as_add_arq_rb(ad, arq); - if (!alias) { - /* - * 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]); + as_add_arq_rb(ad, arq); + if (rq_mergeable(arq->request)) + as_add_arq_hash(ad, arq); - if (rq_mergeable(arq->request)) - as_add_arq_hash(ad, arq); - as_update_arq(ad, arq); /* keep state machine up to date */ - - } else { - as_add_aliased_request(ad, arq, alias); - - /* - * have we been anticipating this request? - * or does it come from the same process as the one we are - * anticipating for? - */ - if (ad->antic_status == ANTIC_WAIT_REQ - || ad->antic_status == ANTIC_WAIT_NEXT) { - if (as_can_break_anticipation(ad, arq)) - as_antic_stop(ad); - } - } + /* + * 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]); + as_update_arq(ad, arq); /* keep state machine up to date */ arq->state = AS_RQ_QUEUED; } @@ -1536,23 +1479,8 @@ static void as_merged_request(request_queue_t *q, struct request *req) * if the merge was a front merge, we need to reposition request */ if (rq_rb_key(req) != arq->rb_key) { - struct as_rq *alias, *next_arq = NULL; - - if (ad->next_arq[arq->is_sync] == arq) - next_arq = as_find_next_arq(ad, arq); - - /* - * Note! We should really be moving any old aliased requests - * off this request and try to insert them into the rbtree. We - * currently don't bother. Ditto the next function. - */ as_del_arq_rb(ad, arq); - if ((alias = as_add_arq_rb(ad, arq))) { - list_del_init(&arq->fifo); - as_add_aliased_request(ad, arq, alias); - if (next_arq) - ad->next_arq[arq->is_sync] = next_arq; - } + as_add_arq_rb(ad, arq); /* * Note! At this stage of this and the next function, our next * request may not be optimal - eg the request may have "grown" @@ -1579,18 +1507,8 @@ static void as_merged_requests(request_queue_t *q, struct request *req, as_add_arq_hash(ad, arq); if (rq_rb_key(req) != arq->rb_key) { - struct as_rq *alias, *next_arq = NULL; - - if (ad->next_arq[arq->is_sync] == arq) - next_arq = as_find_next_arq(ad, arq); - as_del_arq_rb(ad, arq); - if ((alias = as_add_arq_rb(ad, arq))) { - list_del_init(&arq->fifo); - as_add_aliased_request(ad, arq, alias); - if (next_arq) - ad->next_arq[arq->is_sync] = next_arq; - } + as_add_arq_rb(ad, arq); } /* @@ -1610,18 +1528,6 @@ static void as_merged_requests(request_queue_t *q, struct request *req, } /* - * Transfer list of aliases - */ - while (!list_empty(&next->queuelist)) { - struct request *__rq = list_entry_rq(next->queuelist.next); - struct as_rq *__arq = RQ_DATA(__rq); - - list_move_tail(&__rq->queuelist, &req->queuelist); - - WARN_ON(__arq->state != AS_RQ_QUEUED); - } - - /* * kill knowledge of next, this one is a goner */ as_remove_queued_request(q, next); |
