X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=block%2Fmq-deadline.c;h=36920670dccc35f3c4d019423a53754400c3a40a;hb=ced119b6308df8ad2e4345e88f94d2bdcd6d6d4e;hp=a09761cbdf12e58eb1357d00fe3c69a079810585;hpb=12f41321ce769b10a3770f6b39e14cb5d6ee97a4;p=linux-2.6-microblaze.git diff --git a/block/mq-deadline.c b/block/mq-deadline.c index a09761cbdf12..36920670dccc 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -31,11 +31,6 @@ */ static const int read_expire = HZ / 2; /* max time before a read is submitted. */ static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */ -/* - * Time after which to dispatch lower priority requests even if higher - * priority requests are pending. - */ -static const int aging_expire = 10 * HZ; static const int writes_starved = 2; /* max times reads can starve a write */ static const int fifo_batch = 16; /* # of sequential requests treated as one by the above parameters. For throughput. */ @@ -103,7 +98,6 @@ struct deadline_data { int writes_starved; int front_merges; u32 async_depth; - int aging_expire; spinlock_t lock; spinlock_t zone_lock; @@ -369,11 +363,10 @@ deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio, /* * deadline_dispatch_requests selects the best request according to - * read/write expire, fifo_batch, etc and with a start time <= @latest. + * read/write expire, fifo_batch, etc */ static struct request *__dd_dispatch_request(struct deadline_data *dd, - struct dd_per_prio *per_prio, - u64 latest_start_ns) + struct dd_per_prio *per_prio) { struct request *rq, *next_rq; enum dd_data_dir data_dir; @@ -385,8 +378,6 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd, if (!list_empty(&per_prio->dispatch)) { rq = list_first_entry(&per_prio->dispatch, struct request, queuelist); - if (rq->start_time_ns > latest_start_ns) - return NULL; list_del_init(&rq->queuelist); goto done; } @@ -464,8 +455,6 @@ dispatch_find_request: dd->batching = 0; dispatch_request: - if (rq->start_time_ns > latest_start_ns) - return NULL; /* * rq is the selected appropriate request. */ @@ -494,32 +483,15 @@ done: static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx) { struct deadline_data *dd = hctx->queue->elevator->elevator_data; - const u64 now_ns = ktime_get_ns(); - struct request *rq = NULL; + struct request *rq; enum dd_prio prio; spin_lock(&dd->lock); - /* - * Start with dispatching requests whose deadline expired more than - * aging_expire jiffies ago. - */ - for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) { - rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns - - jiffies_to_nsecs(dd->aging_expire)); - if (rq) - goto unlock; - } - /* - * Next, dispatch requests in priority order. Ignore lower priority - * requests if any higher priority requests are pending. - */ for (prio = 0; prio <= DD_PRIO_MAX; prio++) { - rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns); - if (rq || dd_queued(dd, prio)) + rq = __dd_dispatch_request(dd, &dd->per_prio[prio]); + if (rq) break; } - -unlock: spin_unlock(&dd->lock); return rq; @@ -620,7 +592,6 @@ static int dd_init_sched(struct request_queue *q, struct elevator_type *e) dd->front_merges = 1; dd->last_dir = DD_WRITE; dd->fifo_batch = fifo_batch; - dd->aging_expire = aging_expire; spin_lock_init(&dd->lock); spin_lock_init(&dd->zone_lock); @@ -711,6 +682,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, prio = ioprio_class_to_prio[ioprio_class]; dd_count(dd, inserted, prio); + rq->elv.priv[0] = (void *)(uintptr_t)1; if (blk_mq_sched_try_insert_merge(q, rq, &free)) { blk_mq_free_requests(&free); @@ -759,12 +731,10 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, spin_unlock(&dd->lock); } -/* - * Nothing to do here. This is defined only to ensure that .finish_request - * method is called upon request completion. - */ +/* Callback from inside blk_mq_rq_ctx_init(). */ static void dd_prepare_request(struct request *rq) { + rq->elv.priv[0] = NULL; } /* @@ -791,7 +761,14 @@ static void dd_finish_request(struct request *rq) const enum dd_prio prio = ioprio_class_to_prio[ioprio_class]; struct dd_per_prio *per_prio = &dd->per_prio[prio]; - dd_count(dd, completed, prio); + /* + * The block layer core may call dd_finish_request() without having + * called dd_insert_requests(). Hence only update statistics for + * requests for which dd_insert_requests() has been called. See also + * blk_mq_request_bypass_insert(). + */ + if (rq->elv.priv[0]) + dd_count(dd, completed, prio); if (blk_queue_is_zoned(q)) { unsigned long flags; @@ -836,7 +813,6 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \ #define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR)) SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]); SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]); -SHOW_JIFFIES(deadline_aging_expire_show, dd->aging_expire); SHOW_INT(deadline_writes_starved_show, dd->writes_starved); SHOW_INT(deadline_front_merges_show, dd->front_merges); SHOW_INT(deadline_async_depth_show, dd->front_merges); @@ -866,7 +842,6 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies) STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX); STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX); -STORE_JIFFIES(deadline_aging_expire_store, &dd->aging_expire, 0, INT_MAX); STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX); STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1); STORE_INT(deadline_async_depth_store, &dd->front_merges, 1, INT_MAX); @@ -885,7 +860,6 @@ static struct elv_fs_entry deadline_attrs[] = { DD_ATTR(front_merges), DD_ATTR(async_depth), DD_ATTR(fifo_batch), - DD_ATTR(aging_expire), __ATTR_NULL };