diff options
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r-- | block/cfq-iosched.c | 276 |
1 files changed, 157 insertions, 119 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 9c4b679..aa1e953 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -150,7 +150,7 @@ struct cfq_data { * idle window management */ struct timer_list idle_slice_timer; - struct delayed_work unplug_work; + struct work_struct unplug_work; struct cfq_queue *active_queue; struct cfq_io_context *active_cic; @@ -196,6 +196,7 @@ enum cfqq_state_flags { CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ CFQ_CFQQ_FLAG_sync, /* synchronous queue */ CFQ_CFQQ_FLAG_coop, /* has done a coop jump of the queue */ + CFQ_CFQQ_FLAG_coop_preempt, /* coop preempt */ }; #define CFQ_CFQQ_FNS(name) \ @@ -222,6 +223,7 @@ CFQ_CFQQ_FNS(prio_changed); CFQ_CFQQ_FNS(slice_new); CFQ_CFQQ_FNS(sync); CFQ_CFQQ_FNS(coop); +CFQ_CFQQ_FNS(coop_preempt); #undef CFQ_CFQQ_FNS #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ @@ -230,7 +232,7 @@ CFQ_CFQQ_FNS(coop); blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) static void cfq_dispatch_insert(struct request_queue *, struct request *); -static struct cfq_queue *cfq_get_queue(struct cfq_data *, int, +static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool, struct io_context *, gfp_t); static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, struct io_context *); @@ -241,40 +243,35 @@ static inline int rq_in_driver(struct cfq_data *cfqd) } static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, - int is_sync) + bool is_sync) { - return cic->cfqq[!!is_sync]; + return cic->cfqq[is_sync]; } static inline void cic_set_cfqq(struct cfq_io_context *cic, - struct cfq_queue *cfqq, int is_sync) + struct cfq_queue *cfqq, bool is_sync) { - cic->cfqq[!!is_sync] = cfqq; + cic->cfqq[is_sync] = cfqq; } /* * We regard a request as SYNC, if it's either a read or has the SYNC bit * set (in which case it could also be direct WRITE). */ -static inline int cfq_bio_sync(struct bio *bio) +static inline bool cfq_bio_sync(struct bio *bio) { - if (bio_data_dir(bio) == READ || bio_rw_flagged(bio, BIO_RW_SYNCIO)) - return 1; - - return 0; + return bio_data_dir(bio) == READ || bio_rw_flagged(bio, BIO_RW_SYNCIO); } /* * scheduler run of queue, if there are requests pending and no one in the * driver that will restart queueing */ -static inline void cfq_schedule_dispatch(struct cfq_data *cfqd, - unsigned long delay) +static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) { if (cfqd->busy_queues) { cfq_log(cfqd, "schedule dispatch"); - kblockd_schedule_delayed_work(cfqd->queue, &cfqd->unplug_work, - delay); + kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); } } @@ -290,7 +287,7 @@ static int cfq_queue_empty(struct request_queue *q) * if a queue is marked sync and has sync io queued. A sync queue with async * io only, should not get full sync slice length. */ -static inline int cfq_prio_slice(struct cfq_data *cfqd, int sync, +static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, unsigned short prio) { const int base_slice = cfqd->cfq_slice[sync]; @@ -318,7 +315,7 @@ cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) * isn't valid until the first request from the dispatch is activated * and the slice time set. */ -static inline int cfq_slice_used(struct cfq_queue *cfqq) +static inline bool cfq_slice_used(struct cfq_queue *cfqq) { if (cfq_cfqq_slice_new(cfqq)) return 0; @@ -493,7 +490,7 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd, * we will service the queues. */ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, - int add_front) + bool add_front) { struct rb_node **p, *parent; struct cfq_queue *__cfqq; @@ -509,11 +506,20 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, } else rb_key += jiffies; } else if (!add_front) { + /* + * Get our rb key offset. Subtract any residual slice + * value carried from last service. A negative resid + * count indicates slice overrun, and this should position + * the next service time further away in the tree. + */ rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; - rb_key += cfqq->slice_resid; + rb_key -= cfqq->slice_resid; cfqq->slice_resid = 0; - } else - rb_key = 0; + } else { + rb_key = -HZ; + __cfqq = cfq_rb_first(&cfqd->service_tree); + rb_key += __cfqq ? __cfqq->rb_key : jiffies; + } if (!RB_EMPTY_NODE(&cfqq->rb_node)) { /* @@ -547,7 +553,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, n = &(*p)->rb_left; else if (cfq_class_idle(cfqq) > cfq_class_idle(__cfqq)) n = &(*p)->rb_right; - else if (rb_key < __cfqq->rb_key) + else if (time_before(rb_key, __cfqq->rb_key)) n = &(*p)->rb_left; else n = &(*p)->rb_right; @@ -827,8 +833,10 @@ cfq_merged_requests(struct request_queue *q, struct request *rq, * reposition in fifo if next is older than rq */ if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && - time_before(next->start_time, rq->start_time)) + time_before(rq_fifo_time(next), rq_fifo_time(rq))) { list_move(&rq->queuelist, &next->queuelist); + rq_set_fifo_time(rq, rq_fifo_time(next)); + } cfq_remove_request(next); } @@ -844,7 +852,7 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq, * Disallow merge of a sync bio into an async request. */ if (cfq_bio_sync(bio) && !rq_is_sync(rq)) - return 0; + return false; /* * Lookup the cfqq that this bio will be queued with. Allow @@ -852,13 +860,10 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq, */ cic = cfq_cic_lookup(cfqd, current->io_context); if (!cic) - return 0; + return false; cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); - if (cfqq == RQ_CFQQ(rq)) - return 1; - - return 0; + return cfqq == RQ_CFQQ(rq); } static void __cfq_set_active_queue(struct cfq_data *cfqd, @@ -886,7 +891,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd, */ static void __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, - int timed_out) + bool timed_out) { cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); @@ -914,7 +919,7 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, } } -static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out) +static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) { struct cfq_queue *cfqq = cfqd->active_queue; @@ -942,10 +947,13 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, { if (!cfqq) { cfqq = cfq_get_next_queue(cfqd); - if (cfqq) + if (cfqq && !cfq_cfqq_coop_preempt(cfqq)) cfq_clear_cfqq_coop(cfqq); } + if (cfqq) + cfq_clear_cfqq_coop_preempt(cfqq); + __cfq_set_active_queue(cfqd, cfqq); return cfqq; } @@ -1026,7 +1034,7 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, */ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, struct cfq_queue *cur_cfqq, - int probe) + bool probe) { struct cfq_queue *cfqq; @@ -1090,6 +1098,15 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) if (!cic || !atomic_read(&cic->ioc->nr_tasks)) return; + /* + * If our average think time is larger than the remaining time + * slice, then don't idle. This avoids overrunning the allotted + * time slice. + */ + if (sample_valid(cic->ttime_samples) && + (cfqq->slice_end - jiffies < cic->ttime_mean)) + return; + cfq_mark_cfqq_wait_request(cfqq); /* @@ -1129,9 +1146,7 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) */ static struct request *cfq_check_fifo(struct cfq_queue *cfqq) { - struct cfq_data *cfqd = cfqq->cfqd; - struct request *rq; - int fifo; + struct request *rq = NULL; if (cfq_cfqq_fifo_expire(cfqq)) return NULL; @@ -1141,13 +1156,11 @@ static struct request *cfq_check_fifo(struct cfq_queue *cfqq) if (list_empty(&cfqq->fifo)) return NULL; - fifo = cfq_cfqq_sync(cfqq); rq = rq_entry_fifo(cfqq->fifo.next); - - if (time_before(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) + if (time_before(jiffies, rq_fifo_time(rq))) rq = NULL; - cfq_log_cfqq(cfqd, cfqq, "fifo=%p", rq); + cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); return rq; } @@ -1248,67 +1261,21 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) return dispatched; } -/* - * Dispatch a request from cfqq, moving them to the request queue - * dispatch list. - */ -static void cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) -{ - struct request *rq; - - BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); - - /* - * follow expired path, else get first next available - */ - rq = cfq_check_fifo(cfqq); - if (!rq) - rq = cfqq->next_rq; - - /* - * insert request into driver dispatch list - */ - cfq_dispatch_insert(cfqd->queue, rq); - - if (!cfqd->active_cic) { - struct cfq_io_context *cic = RQ_CIC(rq); - - atomic_long_inc(&cic->ioc->refcount); - cfqd->active_cic = cic; - } -} - -/* - * Find the cfqq that we need to service and move a request from that to the - * dispatch list - */ -static int cfq_dispatch_requests(struct request_queue *q, int force) +static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) { - struct cfq_data *cfqd = q->elevator->elevator_data; - struct cfq_queue *cfqq; unsigned int max_dispatch; - if (!cfqd->busy_queues) - return 0; - - if (unlikely(force)) - return cfq_forced_dispatch(cfqd); - - cfqq = cfq_select_queue(cfqd); - if (!cfqq) - return 0; - /* * Drain async requests before we start sync IO */ if (cfq_cfqq_idle_window(cfqq) && cfqd->rq_in_driver[BLK_RW_ASYNC]) - return 0; + return false; /* * If this is an async queue and we have sync IO in flight, let it wait */ if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) - return 0; + return false; max_dispatch = cfqd->cfq_quantum; if (cfq_class_idle(cfqq)) @@ -1322,13 +1289,13 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) * idle queue must always only have a single IO in flight */ if (cfq_class_idle(cfqq)) - return 0; + return false; /* * We have other queues, don't allow more IO from this one */ if (cfqd->busy_queues > 1) - return 0; + return false; /* * Sole queue user, allow bigger slice @@ -1352,13 +1319,72 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) max_dispatch = depth; } - if (cfqq->dispatched >= max_dispatch) + /* + * If we're below the current max, allow a dispatch + */ + return cfqq->dispatched < max_dispatch; +} + +/* + * Dispatch a request from cfqq, moving them to the request queue + * dispatch list. + */ +static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) +{ + struct request *rq; + + BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); + + if (!cfq_may_dispatch(cfqd, cfqq)) + return false; + + /* + * follow expired path, else get first next available + */ + rq = cfq_check_fifo(cfqq); + if (!rq) + rq = cfqq->next_rq; + + /* + * insert request into driver dispatch list + */ + cfq_dispatch_insert(cfqd->queue, rq); + + if (!cfqd->active_cic) { + struct cfq_io_context *cic = RQ_CIC(rq); + + atomic_long_inc(&cic->ioc->refcount); + cfqd->active_cic = cic; + } + + return true; +} + +/* + * Find the cfqq that we need to service and move a request from that to the + * dispatch list + */ +static int cfq_dispatch_requests(struct request_queue *q, int force) +{ + struct cfq_data *cfqd = q->elevator->elevator_data; + struct cfq_queue *cfqq; + + if (!cfqd->busy_queues) + return 0; + + if (unlikely(force)) + return cfq_forced_dispatch(cfqd); + + cfqq = cfq_select_queue(cfqd); + if (!cfqq) return 0; /* - * Dispatch a request from this cfqq + * Dispatch a request from this cfqq, if it is allowed */ - cfq_dispatch_request(cfqd, cfqq); + if (!cfq_dispatch_request(cfqd, cfqq)) + return 0; + cfqq->slice_dispatch++; cfq_clear_cfqq_must_dispatch(cfqq); @@ -1399,7 +1425,7 @@ static void cfq_put_queue(struct cfq_queue *cfqq) if (unlikely(cfqd->active_queue == cfqq)) { __cfq_slice_expired(cfqd, cfqq, 0); - cfq_schedule_dispatch(cfqd, 0); + cfq_schedule_dispatch(cfqd); } kmem_cache_free(cfq_pool, cfqq); @@ -1494,7 +1520,7 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) { if (unlikely(cfqq == cfqd->active_queue)) { __cfq_slice_expired(cfqd, cfqq, 0); - cfq_schedule_dispatch(cfqd, 0); + cfq_schedule_dispatch(cfqd); } cfq_put_queue(cfqq); @@ -1658,7 +1684,7 @@ static void cfq_ioc_set_ioprio(struct io_context *ioc) } static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, - pid_t pid, int is_sync) + pid_t pid, bool is_sync) { RB_CLEAR_NODE(&cfqq->rb_node); RB_CLEAR_NODE(&cfqq->p_node); @@ -1678,7 +1704,7 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, } static struct cfq_queue * -cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync, +cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, gfp_t gfp_mask) { struct cfq_queue *cfqq, *new_cfqq = NULL; @@ -1742,7 +1768,7 @@ cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) } static struct cfq_queue * -cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct io_context *ioc, +cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, gfp_t gfp_mask) { const int ioprio = task_ioprio(ioc); @@ -1977,7 +2003,10 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, (!cfqd->cfq_latency && cfqd->hw_tag && CIC_SEEKY(cic))) enable_idle = 0; else if (sample_valid(cic->ttime_samples)) { - if (cic->ttime_mean > cfqd->cfq_slice_idle) + unsigned int slice_idle = cfqd->cfq_slice_idle; + if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) + slice_idle = msecs_to_jiffies(CFQ_MIN_TT); + if (cic->ttime_mean > slice_idle) enable_idle = 0; else enable_idle = 1; @@ -1996,7 +2025,7 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, * Check if new_cfqq should preempt the currently active queue. Return 0 for * no or if we aren't sure, a 1 will cause a preempt. */ -static int +static bool cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, struct request *rq) { @@ -2004,48 +2033,56 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, cfqq = cfqd->active_queue; if (!cfqq) - return 0; + return false; if (cfq_slice_used(cfqq)) - return 1; + return true; if (cfq_class_idle(new_cfqq)) - return 0; + return false; if (cfq_class_idle(cfqq)) - return 1; + return true; /* * if the new request is sync, but the currently running queue is * not, let the sync request have priority. */ if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) - return 1; + return true; /* * So both queues are sync. Let the new request get disk time if * it's a metadata request and the current queue is doing regular IO. */ if (rq_is_meta(rq) && !cfqq->meta_pending) - return 1; + return true; /* * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. */ if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) - return 1; + return true; if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) - return 0; + return false; /* * if this request is as-good as one we would expect from the * current cfqq, let it preempt */ - if (cfq_rq_close(cfqd, rq)) - return 1; + if (cfq_rq_close(cfqd, rq) && (!cfq_cfqq_coop(new_cfqq) || + cfqd->busy_queues == 1)) { + /* + * Mark new queue coop_preempt, so its coop flag will not be + * cleared when new queue gets scheduled at the very first time + */ + cfq_mark_cfqq_coop_preempt(new_cfqq); + cfq_mark_cfqq_coop(new_cfqq); + return true; + } - return 0; + return false; } /* @@ -2130,6 +2167,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq) cfq_add_rq_rb(rq); + rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]); list_add_tail(&rq->queuelist, &cfqq->fifo); cfq_rq_enqueued(cfqd, cfqq, rq); @@ -2211,7 +2249,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) } if (!rq_in_driver(cfqd)) - cfq_schedule_dispatch(cfqd, 0); + cfq_schedule_dispatch(cfqd); } /* @@ -2309,7 +2347,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_io_context *cic; const int rw = rq_data_dir(rq); - const int is_sync = rq_is_sync(rq); + const bool is_sync = rq_is_sync(rq); struct cfq_queue *cfqq; unsigned long flags; @@ -2341,7 +2379,7 @@ queue_fail: if (cic) put_io_context(cic->ioc); - cfq_schedule_dispatch(cfqd, 0); + cfq_schedule_dispatch(cfqd); spin_unlock_irqrestore(q->queue_lock, flags); cfq_log(cfqd, "set_request fail"); return 1; @@ -2350,7 +2388,7 @@ queue_fail: static void cfq_kick_queue(struct work_struct *work) { struct cfq_data *cfqd = - container_of(work, struct cfq_data, unplug_work.work); + container_of(work, struct cfq_data, unplug_work); struct request_queue *q = cfqd->queue; spin_lock_irq(q->queue_lock); @@ -2404,7 +2442,7 @@ static void cfq_idle_slice_timer(unsigned long data) expire: cfq_slice_expired(cfqd, timed_out); out_kick: - cfq_schedule_dispatch(cfqd, 0); + cfq_schedule_dispatch(cfqd); out_cont: spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); } @@ -2412,7 +2450,7 @@ out_cont: static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) { del_timer_sync(&cfqd->idle_slice_timer); - cancel_delayed_work_sync(&cfqd->unplug_work); + cancel_work_sync(&cfqd->unplug_work); } static void cfq_put_async_queues(struct cfq_data *cfqd) @@ -2494,7 +2532,7 @@ static void *cfq_init_queue(struct request_queue *q) cfqd->idle_slice_timer.function = cfq_idle_slice_timer; cfqd->idle_slice_timer.data = (unsigned long) cfqd; - INIT_DELAYED_WORK(&cfqd->unplug_work, cfq_kick_queue); + INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); cfqd->cfq_quantum = cfq_quantum; cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |