X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=block%2Fcfq-iosched.c;h=6a062eebbd15301320e7491b5dd45d17f2204a3c;hb=e436fdae70a31102d2be32969b80fe8545edebd9;hp=baef5fc7cff8b5ca3d184e3d48efdd4be7376203;hpb=0a31bd5f2bbb6473ef9d24f0063ca91cfa678b64;p=safe%2Fjmp%2Flinux-2.6 diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index baef5fc..6a062ee 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -11,24 +11,27 @@ #include #include #include +#include /* * tunables */ -static const int cfq_quantum = 4; /* max queue in one round of service */ +/* max queue in one round of service */ +static const int cfq_quantum = 4; static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; -static const int cfq_back_max = 16 * 1024; /* maximum backwards seek, in KiB */ -static const int cfq_back_penalty = 2; /* penalty of a backwards seek */ - +/* maximum backwards seek, in KiB */ +static const int cfq_back_max = 16 * 1024; +/* penalty of a backwards seek */ +static const int cfq_back_penalty = 2; static const int cfq_slice_sync = HZ / 10; static int cfq_slice_async = HZ / 25; static const int cfq_slice_async_rq = 2; static int cfq_slice_idle = HZ / 125; /* - * grace period before allowing idle class to get disk access + * offset from end of service tree */ -#define CFQ_IDLE_GRACE (HZ / 10) +#define CFQ_IDLE_DELAY (HZ / 5) /* * below this threshold, we consider thinktime immediate @@ -36,15 +39,18 @@ static int cfq_slice_idle = HZ / 125; #define CFQ_MIN_TT (2) #define CFQ_SLICE_SCALE (5) +#define CFQ_HW_QUEUE_MIN (5) -#define RQ_CIC(rq) ((struct cfq_io_context*)(rq)->elevator_private) -#define RQ_CFQQ(rq) ((rq)->elevator_private2) +#define RQ_CIC(rq) \ + ((struct cfq_io_context *) (rq)->elevator_private) +#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) static struct kmem_cache *cfq_pool; static struct kmem_cache *cfq_ioc_pool; static DEFINE_PER_CPU(unsigned long, ioc_count); static struct completion *ioc_gone; +static DEFINE_SPINLOCK(ioc_gone_lock); #define CFQ_PRIO_LISTS IOPRIO_BE_NR #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) @@ -71,7 +77,7 @@ struct cfq_rb_root { * Per block device queue structure */ struct cfq_data { - request_queue_t *queue; + struct request_queue *queue; /* * rr list of queues with requests and the count of them @@ -81,7 +87,14 @@ struct cfq_data { int rq_in_driver; int sync_flight; + + /* + * queue-depth detection + */ + int rq_queued; int hw_tag; + int hw_tag_samples; + int rq_in_driver_peak; /* * idle window management @@ -92,7 +105,11 @@ struct cfq_data { struct cfq_queue *active_queue; struct cfq_io_context *active_cic; - struct timer_list idle_class_timer; + /* + * async queue for each priority case + */ + struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; + struct cfq_queue *async_idle_cfqq; sector_t last_position; unsigned long last_end_request; @@ -109,9 +126,6 @@ struct cfq_data { unsigned int cfq_slice_idle; struct list_head cic_list; - - sector_t new_seek_mean; - u64 new_seek_total; }; /* @@ -120,6 +134,8 @@ struct cfq_data { struct cfq_queue { /* reference count */ atomic_t ref; + /* various state flags, see below */ + unsigned int flags; /* parent cfq_data */ struct cfq_data *cfqd; /* service_tree member */ @@ -134,14 +150,14 @@ struct cfq_queue { int queued[2]; /* currently allocated requests */ int allocated[2]; - /* pending metadata requests */ - int meta_pending; /* fifo list of requests in sort_list */ struct list_head fifo; unsigned long slice_end; long slice_resid; + /* pending metadata requests */ + int meta_pending; /* number of requests that are on the dispatch list or inside driver */ int dispatched; @@ -149,10 +165,7 @@ struct cfq_queue { unsigned short ioprio, org_ioprio; unsigned short ioprio_class, org_ioprio_class; - /* various state flags, see below */ - unsigned int flags; - - sector_t last_request_pos; + pid_t pid; }; enum cfqq_state_flags { @@ -172,15 +185,15 @@ enum cfqq_state_flags { #define CFQ_CFQQ_FNS(name) \ static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ { \ - cfqq->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ + (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ } \ static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ { \ - cfqq->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ + (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ } \ static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ { \ - return (cfqq->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ + return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ } CFQ_CFQQ_FNS(on_rr); @@ -196,10 +209,15 @@ CFQ_CFQQ_FNS(slice_new); CFQ_CFQQ_FNS(sync); #undef CFQ_CFQQ_FNS -static void cfq_dispatch_insert(request_queue_t *, struct request *); +#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ + blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) +#define cfq_log(cfqd, fmt, args...) \ + 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, - struct task_struct *, gfp_t); -static struct cfq_io_context *cfq_cic_rb_lookup(struct cfq_data *, + struct io_context *, gfp_t); +static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, struct io_context *); static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, @@ -232,11 +250,13 @@ static inline int cfq_bio_sync(struct bio *bio) */ static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) { - if (cfqd->busy_queues) - kblockd_schedule_work(&cfqd->unplug_work); + if (cfqd->busy_queues) { + cfq_log(cfqd, "schedule dispatch"); + kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); + } } -static int cfq_queue_empty(request_queue_t *q) +static int cfq_queue_empty(struct request_queue *q) { struct cfq_data *cfqd = q->elevator->elevator_data; @@ -268,6 +288,7 @@ static inline void cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { cfqq->slice_end = cfq_prio_to_slice(cfqd, cfqq) + jiffies; + cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); } /* @@ -383,12 +404,15 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2) /* * The below is leftmost cache rbtree addon */ -static struct rb_node *cfq_rb_first(struct cfq_rb_root *root) +static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) { if (!root->left) root->left = rb_first(&root->rb); - return root->left; + if (root->left) + return rb_entry(root->left, struct cfq_queue, rb_node); + + return NULL; } static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) @@ -445,12 +469,20 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd, static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, int add_front) { - struct rb_node **p = &cfqd->service_tree.rb.rb_node; - struct rb_node *parent = NULL; + struct rb_node **p, *parent; + struct cfq_queue *__cfqq; unsigned long rb_key; int left; - if (!add_front) { + if (cfq_class_idle(cfqq)) { + rb_key = CFQ_IDLE_DELAY; + parent = rb_last(&cfqd->service_tree.rb); + if (parent && parent != &cfqq->rb_node) { + __cfqq = rb_entry(parent, struct cfq_queue, rb_node); + rb_key += __cfqq->rb_key; + } else + rb_key += jiffies; + } else if (!add_front) { rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; rb_key += cfqq->slice_resid; cfqq->slice_resid = 0; @@ -468,8 +500,9 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, } left = 1; + parent = NULL; + p = &cfqd->service_tree.rb.rb_node; while (*p) { - struct cfq_queue *__cfqq; struct rb_node **n; parent = *p; @@ -523,9 +556,9 @@ static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) * add to busy list of queues for service, trying to be fair in ordering * the pending list according to last request service */ -static inline void -cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) +static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) { + cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); BUG_ON(cfq_cfqq_on_rr(cfqq)); cfq_mark_cfqq_on_rr(cfqq); cfqd->busy_queues++; @@ -537,9 +570,9 @@ cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) * Called when the cfqq no longer has requests pending, remove it from * the service tree. */ -static inline void -cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) +static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) { + cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); BUG_ON(!cfq_cfqq_on_rr(cfqq)); cfq_clear_cfqq_on_rr(cfqq); @@ -553,7 +586,7 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) /* * rb tree support functions */ -static inline void cfq_del_rq_rb(struct request *rq) +static void cfq_del_rq_rb(struct request *rq) { struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_data *cfqd = cfqq->cfqd; @@ -593,8 +626,7 @@ static void cfq_add_rq_rb(struct request *rq) BUG_ON(!cfqq->next_rq); } -static inline void -cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) +static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) { elv_rb_del(&cfqq->sort_list, rq); cfqq->queued[rq_is_sync(rq)]--; @@ -608,7 +640,7 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) struct cfq_io_context *cic; struct cfq_queue *cfqq; - cic = cfq_cic_rb_lookup(cfqd, tsk->io_context); + cic = cfq_cic_lookup(cfqd, tsk->io_context); if (!cic) return NULL; @@ -622,30 +654,25 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) return NULL; } -static void cfq_activate_request(request_queue_t *q, struct request *rq) +static void cfq_activate_request(struct request_queue *q, struct request *rq) { struct cfq_data *cfqd = q->elevator->elevator_data; cfqd->rq_in_driver++; - - /* - * If the depth is larger 1, it really could be queueing. But lets - * make the mark a little higher - idling could still be good for - * low queueing, and a low queueing number could also just indicate - * a SCSI mid layer like behaviour where limit+1 is often seen. - */ - if (!cfqd->hw_tag && cfqd->rq_in_driver > 4) - cfqd->hw_tag = 1; + cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", + cfqd->rq_in_driver); cfqd->last_position = rq->hard_sector + rq->hard_nr_sectors; } -static void cfq_deactivate_request(request_queue_t *q, struct request *rq) +static void cfq_deactivate_request(struct request_queue *q, struct request *rq) { struct cfq_data *cfqd = q->elevator->elevator_data; WARN_ON(!cfqd->rq_in_driver); cfqd->rq_in_driver--; + cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", + cfqd->rq_in_driver); } static void cfq_remove_request(struct request *rq) @@ -658,13 +685,15 @@ static void cfq_remove_request(struct request *rq) list_del_init(&rq->queuelist); cfq_del_rq_rb(rq); + cfqq->cfqd->rq_queued--; if (rq_is_meta(rq)) { WARN_ON(!cfqq->meta_pending); cfqq->meta_pending--; } } -static int cfq_merge(request_queue_t *q, struct request **req, struct bio *bio) +static int cfq_merge(struct request_queue *q, struct request **req, + struct bio *bio) { struct cfq_data *cfqd = q->elevator->elevator_data; struct request *__rq; @@ -678,7 +707,7 @@ static int cfq_merge(request_queue_t *q, struct request **req, struct bio *bio) return ELEVATOR_NO_MERGE; } -static void cfq_merged_request(request_queue_t *q, struct request *req, +static void cfq_merged_request(struct request_queue *q, struct request *req, int type) { if (type == ELEVATOR_FRONT_MERGE) { @@ -689,7 +718,7 @@ static void cfq_merged_request(request_queue_t *q, struct request *req, } static void -cfq_merged_requests(request_queue_t *q, struct request *rq, +cfq_merged_requests(struct request_queue *q, struct request *rq, struct request *next) { /* @@ -702,7 +731,7 @@ cfq_merged_requests(request_queue_t *q, struct request *rq, cfq_remove_request(next); } -static int cfq_allow_merge(request_queue_t *q, struct request *rq, +static int cfq_allow_merge(struct request_queue *q, struct request *rq, struct bio *bio) { struct cfq_data *cfqd = q->elevator->elevator_data; @@ -719,7 +748,7 @@ static int cfq_allow_merge(request_queue_t *q, struct request *rq, * Lookup the cfqq that this bio will be queued with. Allow * merge only if rq is queued there. */ - cic = cfq_cic_rb_lookup(cfqd, current->io_context); + cic = cfq_cic_lookup(cfqd, current->io_context); if (!cic) return 0; @@ -730,15 +759,11 @@ static int cfq_allow_merge(request_queue_t *q, struct request *rq, return 0; } -static inline void -__cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) +static void __cfq_set_active_queue(struct cfq_data *cfqd, + struct cfq_queue *cfqq) { if (cfqq) { - /* - * stop potential idle class queues waiting service - */ - del_timer(&cfqd->idle_class_timer); - + cfq_log_cfqq(cfqd, cfqq, "set_active"); cfqq->slice_end = 0; cfq_clear_cfqq_must_alloc_slice(cfqq); cfq_clear_cfqq_fifo_expire(cfqq); @@ -756,6 +781,8 @@ static void __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, int timed_out) { + cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); + if (cfq_cfqq_wait_request(cfqq)) del_timer(&cfqd->idle_slice_timer); @@ -765,8 +792,10 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, /* * store what was left of this slice, if the queue idled/timed out */ - if (timed_out && !cfq_cfqq_slice_new(cfqq)) + if (timed_out && !cfq_cfqq_slice_new(cfqq)) { cfqq->slice_resid = cfqq->slice_end - jiffies; + cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); + } cfq_resort_rr_list(cfqd, cfqq); @@ -793,32 +822,10 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out) */ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) { - struct cfq_queue *cfqq; - struct rb_node *n; - if (RB_EMPTY_ROOT(&cfqd->service_tree.rb)) return NULL; - n = cfq_rb_first(&cfqd->service_tree); - cfqq = rb_entry(n, struct cfq_queue, rb_node); - - if (cfq_class_idle(cfqq)) { - unsigned long end; - - /* - * if we have idle queues and no rt or be queues had - * pending requests, either allow immediate service if - * the grace period has passed or arm the idle grace - * timer - */ - end = cfqd->last_end_request + CFQ_IDLE_GRACE; - if (time_before(jiffies, end)) { - mod_timer(&cfqd->idle_class_timer, end); - cfqq = NULL; - } - } - - return cfqq; + return cfq_rb_first(&cfqd->service_tree); } /* @@ -871,6 +878,14 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) struct cfq_io_context *cic; unsigned long sl; + /* + * SSD device without seek penalty, disable idling. But only do so + * for devices that support queuing, otherwise we still have a problem + * with sync vs async workloads. + */ + if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) + return; + WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); WARN_ON(cfq_cfqq_slice_new(cfqq)); @@ -881,10 +896,16 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) return; /* + * still requests with the driver, don't idle + */ + if (cfqd->rq_in_driver) + return; + + /* * task has exited, don't wait */ cic = cfqd->active_cic; - if (!cic || !cic->ioc->task) + if (!cic || !atomic_read(&cic->ioc->nr_tasks)) return; /* @@ -907,16 +928,19 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT)); mod_timer(&cfqd->idle_slice_timer, jiffies + sl); + cfq_log(cfqd, "arm_idle: %lu", sl); } /* * Move request from internal lists to the request queue dispatch list. */ -static void cfq_dispatch_insert(request_queue_t *q, struct request *rq) +static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) { struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_queue *cfqq = RQ_CFQQ(rq); + cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); + cfq_remove_request(rq); cfqq->dispatched++; elv_dispatch_sort(q, rq); @@ -928,7 +952,7 @@ static void cfq_dispatch_insert(request_queue_t *q, struct request *rq) /* * return expired entry, or NULL to just start from scratch in rbtree */ -static inline struct request *cfq_check_fifo(struct cfq_queue *cfqq) +static struct request *cfq_check_fifo(struct cfq_queue *cfqq) { struct cfq_data *cfqd = cfqq->cfqd; struct request *rq; @@ -946,8 +970,9 @@ static inline struct request *cfq_check_fifo(struct cfq_queue *cfqq) rq = rq_entry_fifo(cfqq->fifo.next); if (time_before(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) - return NULL; + rq = NULL; + cfq_log_cfqq(cfqd, cfqq, "fifo=%p", rq); return rq; } @@ -1023,7 +1048,8 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq, /* * follow expired path, else get first next available */ - if ((rq = cfq_check_fifo(cfqq)) == NULL) + rq = cfq_check_fifo(cfqq); + if (rq == NULL) rq = cfqq->next_rq; /* @@ -1057,7 +1083,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq, return dispatched; } -static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) +static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) { int dispatched = 0; @@ -1076,23 +1102,21 @@ static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) */ static int cfq_forced_dispatch(struct cfq_data *cfqd) { + struct cfq_queue *cfqq; int dispatched = 0; - struct rb_node *n; - - while ((n = cfq_rb_first(&cfqd->service_tree)) != NULL) { - struct cfq_queue *cfqq = rb_entry(n, struct cfq_queue, rb_node); + while ((cfqq = cfq_rb_first(&cfqd->service_tree)) != NULL) dispatched += __cfq_forced_dispatch_cfqq(cfqq); - } cfq_slice_expired(cfqd, 0); BUG_ON(cfqd->busy_queues); + cfq_log(cfqd, "forced_dispatch=%d\n", dispatched); return dispatched; } -static int cfq_dispatch_requests(request_queue_t *q, int force) +static int cfq_dispatch_requests(struct request_queue *q, int force) { struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_queue *cfqq; @@ -1129,6 +1153,7 @@ static int cfq_dispatch_requests(request_queue_t *q, int force) dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch); } + cfq_log(cfqd, "dispatched=%d", dispatched); return dispatched; } @@ -1147,6 +1172,7 @@ static void cfq_put_queue(struct cfq_queue *cfqq) if (!atomic_dec_and_test(&cfqq->ref)) return; + cfq_log_cfqq(cfqd, cfqq, "put_queue"); BUG_ON(rb_first(&cfqq->sort_list)); BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); BUG_ON(cfq_cfqq_on_rr(cfqq)); @@ -1159,25 +1185,89 @@ static void cfq_put_queue(struct cfq_queue *cfqq) kmem_cache_free(cfq_pool, cfqq); } -static void cfq_free_io_context(struct io_context *ioc) +/* + * Must always be called with the rcu_read_lock() held + */ +static void +__call_for_each_cic(struct io_context *ioc, + void (*func)(struct io_context *, struct cfq_io_context *)) { - struct cfq_io_context *__cic; - struct rb_node *n; - int freed = 0; + struct cfq_io_context *cic; + struct hlist_node *n; - ioc->ioc_data = NULL; + hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) + func(ioc, cic); +} - while ((n = rb_first(&ioc->cic_root)) != NULL) { - __cic = rb_entry(n, struct cfq_io_context, rb_node); - rb_erase(&__cic->rb_node, &ioc->cic_root); - kmem_cache_free(cfq_ioc_pool, __cic); - freed++; +/* + * Call func for each cic attached to this ioc. + */ +static void +call_for_each_cic(struct io_context *ioc, + void (*func)(struct io_context *, struct cfq_io_context *)) +{ + rcu_read_lock(); + __call_for_each_cic(ioc, func); + rcu_read_unlock(); +} + +static void cfq_cic_free_rcu(struct rcu_head *head) +{ + struct cfq_io_context *cic; + + cic = container_of(head, struct cfq_io_context, rcu_head); + + kmem_cache_free(cfq_ioc_pool, cic); + elv_ioc_count_dec(ioc_count); + + if (ioc_gone) { + /* + * CFQ scheduler is exiting, grab exit lock and check + * the pending io context count. If it hits zero, + * complete ioc_gone and set it back to NULL + */ + spin_lock(&ioc_gone_lock); + if (ioc_gone && !elv_ioc_count_read(ioc_count)) { + complete(ioc_gone); + ioc_gone = NULL; + } + spin_unlock(&ioc_gone_lock); } +} - elv_ioc_count_mod(ioc_count, -freed); +static void cfq_cic_free(struct cfq_io_context *cic) +{ + call_rcu(&cic->rcu_head, cfq_cic_free_rcu); +} + +static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) +{ + unsigned long flags; + + BUG_ON(!cic->dead_key); + + spin_lock_irqsave(&ioc->lock, flags); + radix_tree_delete(&ioc->radix_root, cic->dead_key); + hlist_del_rcu(&cic->cic_list); + spin_unlock_irqrestore(&ioc->lock, flags); + + cfq_cic_free(cic); +} - if (ioc_gone && !elv_ioc_count_read(ioc_count)) - complete(ioc_gone); +/* + * Must be called with rcu_read_lock() held or preemption otherwise disabled. + * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), + * and ->trim() which is called with the task lock held + */ +static void cfq_free_io_context(struct io_context *ioc) +{ + /* + * ioc->refcount is zero here, or we are called from elv_unregister(), + * so no more cic's are allowed to be linked into this ioc. So it + * should be ok to iterate over the known list, we will see all cic's + * since no new ones are added. + */ + __call_for_each_cic(ioc, cic_free_func); } static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) @@ -1193,10 +1283,20 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) static void __cfq_exit_single_io_context(struct cfq_data *cfqd, struct cfq_io_context *cic) { + struct io_context *ioc = cic->ioc; + list_del_init(&cic->queue_list); + + /* + * Make sure key == NULL is seen for dead queues + */ smp_wmb(); + cic->dead_key = (unsigned long) cic->key; cic->key = NULL; + if (ioc->ioc_data == cic) + rcu_assign_pointer(ioc->ioc_data, NULL); + if (cic->cfqq[ASYNC]) { cfq_exit_cfqq(cfqd, cic->cfqq[ASYNC]); cic->cfqq[ASYNC] = NULL; @@ -1208,16 +1308,18 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd, } } -static void cfq_exit_single_io_context(struct cfq_io_context *cic) +static void cfq_exit_single_io_context(struct io_context *ioc, + struct cfq_io_context *cic) { struct cfq_data *cfqd = cic->key; if (cfqd) { - request_queue_t *q = cfqd->queue; + struct request_queue *q = cfqd->queue; + unsigned long flags; - spin_lock_irq(q->queue_lock); + spin_lock_irqsave(q->queue_lock, flags); __cfq_exit_single_io_context(cfqd, cic); - spin_unlock_irq(q->queue_lock); + spin_unlock_irqrestore(q->queue_lock, flags); } } @@ -1227,21 +1329,7 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic) */ static void cfq_exit_io_context(struct io_context *ioc) { - struct cfq_io_context *__cic; - struct rb_node *n; - - ioc->ioc_data = NULL; - - /* - * put the reference this task is holding to the various queues - */ - n = rb_first(&ioc->cic_root); - while (n != NULL) { - __cic = rb_entry(n, struct cfq_io_context, rb_node); - - cfq_exit_single_io_context(__cic); - n = rb_next(n); - } + call_for_each_cic(ioc, cfq_exit_single_io_context); } static struct cfq_io_context * @@ -1249,11 +1337,12 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) { struct cfq_io_context *cic; - cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask, cfqd->queue->node); + cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, + cfqd->queue->node); if (cic) { - memset(cic, 0, sizeof(*cic)); cic->last_end_request = jiffies; INIT_LIST_HEAD(&cic->queue_list); + INIT_HLIST_NODE(&cic->cic_list); cic->dtor = cfq_free_io_context; cic->exit = cfq_exit_io_context; elv_ioc_count_inc(ioc_count); @@ -1262,7 +1351,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) return cic; } -static void cfq_init_prio_data(struct cfq_queue *cfqq) +static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) { struct task_struct *tsk = current; int ioprio_class; @@ -1270,30 +1359,30 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq) if (!cfq_cfqq_prio_changed(cfqq)) return; - ioprio_class = IOPRIO_PRIO_CLASS(tsk->ioprio); + ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); switch (ioprio_class) { - default: - printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); - case IOPRIO_CLASS_NONE: - /* - * no prio set, place us in the middle of the BE classes - */ - cfqq->ioprio = task_nice_ioprio(tsk); - cfqq->ioprio_class = IOPRIO_CLASS_BE; - break; - case IOPRIO_CLASS_RT: - cfqq->ioprio = task_ioprio(tsk); - cfqq->ioprio_class = IOPRIO_CLASS_RT; - break; - case IOPRIO_CLASS_BE: - cfqq->ioprio = task_ioprio(tsk); - cfqq->ioprio_class = IOPRIO_CLASS_BE; - break; - case IOPRIO_CLASS_IDLE: - cfqq->ioprio_class = IOPRIO_CLASS_IDLE; - cfqq->ioprio = 7; - cfq_clear_cfqq_idle_window(cfqq); - break; + default: + printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); + case IOPRIO_CLASS_NONE: + /* + * no prio set, inherit CPU scheduling settings + */ + cfqq->ioprio = task_nice_ioprio(tsk); + cfqq->ioprio_class = task_nice_ioclass(tsk); + break; + case IOPRIO_CLASS_RT: + cfqq->ioprio = task_ioprio(ioc); + cfqq->ioprio_class = IOPRIO_CLASS_RT; + break; + case IOPRIO_CLASS_BE: + cfqq->ioprio = task_ioprio(ioc); + cfqq->ioprio_class = IOPRIO_CLASS_BE; + break; + case IOPRIO_CLASS_IDLE: + cfqq->ioprio_class = IOPRIO_CLASS_IDLE; + cfqq->ioprio = 7; + cfq_clear_cfqq_idle_window(cfqq); + break; } /* @@ -1305,7 +1394,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq) cfq_clear_cfqq_prio_changed(cfqq); } -static inline void changed_ioprio(struct cfq_io_context *cic) +static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic) { struct cfq_data *cfqd = cic->key; struct cfq_queue *cfqq; @@ -1319,8 +1408,7 @@ static inline void changed_ioprio(struct cfq_io_context *cic) cfqq = cic->cfqq[ASYNC]; if (cfqq) { struct cfq_queue *new_cfqq; - new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc->task, - GFP_ATOMIC); + new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc, GFP_ATOMIC); if (new_cfqq) { cic->cfqq[ASYNC] = new_cfqq; cfq_put_queue(cfqq); @@ -1336,29 +1424,19 @@ static inline void changed_ioprio(struct cfq_io_context *cic) static void cfq_ioc_set_ioprio(struct io_context *ioc) { - struct cfq_io_context *cic; - struct rb_node *n; - + call_for_each_cic(ioc, changed_ioprio); ioc->ioprio_changed = 0; - - n = rb_first(&ioc->cic_root); - while (n != NULL) { - cic = rb_entry(n, struct cfq_io_context, rb_node); - - changed_ioprio(cic); - n = rb_next(n); - } } static struct cfq_queue * -cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk, - gfp_t gfp_mask) +cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync, + struct io_context *ioc, gfp_t gfp_mask) { struct cfq_queue *cfqq, *new_cfqq = NULL; struct cfq_io_context *cic; retry: - cic = cfq_cic_rb_lookup(cfqd, tsk->io_context); + cic = cfq_cic_lookup(cfqd, ioc); /* cic always exists here */ cfqq = cic_to_cfqq(cic, is_sync); @@ -1374,140 +1452,195 @@ retry: * free memory. */ spin_unlock_irq(cfqd->queue->queue_lock); - new_cfqq = kmem_cache_alloc_node(cfq_pool, gfp_mask|__GFP_NOFAIL, cfqd->queue->node); + new_cfqq = kmem_cache_alloc_node(cfq_pool, + gfp_mask | __GFP_NOFAIL | __GFP_ZERO, + cfqd->queue->node); spin_lock_irq(cfqd->queue->queue_lock); goto retry; } else { - cfqq = kmem_cache_alloc_node(cfq_pool, gfp_mask, cfqd->queue->node); + cfqq = kmem_cache_alloc_node(cfq_pool, + gfp_mask | __GFP_ZERO, + cfqd->queue->node); if (!cfqq) goto out; } - memset(cfqq, 0, sizeof(*cfqq)); - RB_CLEAR_NODE(&cfqq->rb_node); INIT_LIST_HEAD(&cfqq->fifo); atomic_set(&cfqq->ref, 0); cfqq->cfqd = cfqd; - if (is_sync) { - cfq_mark_cfqq_idle_window(cfqq); - cfq_mark_cfqq_sync(cfqq); - } - cfq_mark_cfqq_prio_changed(cfqq); cfq_mark_cfqq_queue_new(cfqq); - cfq_init_prio_data(cfqq); + cfq_init_prio_data(cfqq, ioc); + + if (is_sync) { + if (!cfq_class_idle(cfqq)) + cfq_mark_cfqq_idle_window(cfqq); + cfq_mark_cfqq_sync(cfqq); + } + cfqq->pid = current->pid; + cfq_log_cfqq(cfqd, cfqq, "alloced"); } if (new_cfqq) kmem_cache_free(cfq_pool, new_cfqq); - atomic_inc(&cfqq->ref); out: WARN_ON((gfp_mask & __GFP_WAIT) && !cfqq); return cfqq; } +static struct cfq_queue ** +cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) +{ + switch (ioprio_class) { + case IOPRIO_CLASS_RT: + return &cfqd->async_cfqq[0][ioprio]; + case IOPRIO_CLASS_BE: + return &cfqd->async_cfqq[1][ioprio]; + case IOPRIO_CLASS_IDLE: + return &cfqd->async_idle_cfqq; + default: + BUG(); + } +} + +static struct cfq_queue * +cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct io_context *ioc, + gfp_t gfp_mask) +{ + const int ioprio = task_ioprio(ioc); + const int ioprio_class = task_ioprio_class(ioc); + struct cfq_queue **async_cfqq = NULL; + struct cfq_queue *cfqq = NULL; + + if (!is_sync) { + async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); + cfqq = *async_cfqq; + } + + if (!cfqq) { + cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); + if (!cfqq) + return NULL; + } + + /* + * pin the queue now that it's allocated, scheduler exit will prune it + */ + if (!is_sync && !(*async_cfqq)) { + atomic_inc(&cfqq->ref); + *async_cfqq = cfqq; + } + + atomic_inc(&cfqq->ref); + return cfqq; +} + /* * We drop cfq io contexts lazily, so we may find a dead one. */ static void -cfq_drop_dead_cic(struct io_context *ioc, struct cfq_io_context *cic) +cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, + struct cfq_io_context *cic) { + unsigned long flags; + WARN_ON(!list_empty(&cic->queue_list)); - if (ioc->ioc_data == cic) - ioc->ioc_data = NULL; + spin_lock_irqsave(&ioc->lock, flags); - rb_erase(&cic->rb_node, &ioc->cic_root); - kmem_cache_free(cfq_ioc_pool, cic); - elv_ioc_count_dec(ioc_count); + BUG_ON(ioc->ioc_data == cic); + + radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd); + hlist_del_rcu(&cic->cic_list); + spin_unlock_irqrestore(&ioc->lock, flags); + + cfq_cic_free(cic); } static struct cfq_io_context * -cfq_cic_rb_lookup(struct cfq_data *cfqd, struct io_context *ioc) +cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) { - struct rb_node *n; struct cfq_io_context *cic; - void *k, *key = cfqd; + unsigned long flags; + void *k; if (unlikely(!ioc)) return NULL; + rcu_read_lock(); + /* * we maintain a last-hit cache, to avoid browsing over the tree */ - cic = ioc->ioc_data; - if (cic && cic->key == cfqd) + cic = rcu_dereference(ioc->ioc_data); + if (cic && cic->key == cfqd) { + rcu_read_unlock(); return cic; + } -restart: - n = ioc->cic_root.rb_node; - while (n) { - cic = rb_entry(n, struct cfq_io_context, rb_node); + do { + cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); + rcu_read_unlock(); + if (!cic) + break; /* ->key must be copied to avoid race with cfq_exit_queue() */ k = cic->key; if (unlikely(!k)) { - cfq_drop_dead_cic(ioc, cic); - goto restart; + cfq_drop_dead_cic(cfqd, ioc, cic); + rcu_read_lock(); + continue; } - if (key < k) - n = n->rb_left; - else if (key > k) - n = n->rb_right; - else { - ioc->ioc_data = cic; - return cic; - } - } + spin_lock_irqsave(&ioc->lock, flags); + rcu_assign_pointer(ioc->ioc_data, cic); + spin_unlock_irqrestore(&ioc->lock, flags); + break; + } while (1); - return NULL; + return cic; } -static inline void -cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, - struct cfq_io_context *cic) +/* + * Add cic into ioc, using cfqd as the search key. This enables us to lookup + * the process specific cfq io context when entered from the block layer. + * Also adds the cic to a per-cfqd list, used when this queue is removed. + */ +static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, + struct cfq_io_context *cic, gfp_t gfp_mask) { - struct rb_node **p; - struct rb_node *parent; - struct cfq_io_context *__cic; unsigned long flags; - void *k; + int ret; - cic->ioc = ioc; - cic->key = cfqd; + ret = radix_tree_preload(gfp_mask); + if (!ret) { + cic->ioc = ioc; + cic->key = cfqd; -restart: - parent = NULL; - p = &ioc->cic_root.rb_node; - while (*p) { - parent = *p; - __cic = rb_entry(parent, struct cfq_io_context, rb_node); - /* ->key must be copied to avoid race with cfq_exit_queue() */ - k = __cic->key; - if (unlikely(!k)) { - cfq_drop_dead_cic(ioc, __cic); - goto restart; - } + spin_lock_irqsave(&ioc->lock, flags); + ret = radix_tree_insert(&ioc->radix_root, + (unsigned long) cfqd, cic); + if (!ret) + hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); + spin_unlock_irqrestore(&ioc->lock, flags); - if (cic->key < k) - p = &(*p)->rb_left; - else if (cic->key > k) - p = &(*p)->rb_right; - else - BUG(); + radix_tree_preload_end(); + + if (!ret) { + spin_lock_irqsave(cfqd->queue->queue_lock, flags); + list_add(&cic->queue_list, &cfqd->cic_list); + spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); + } } - rb_link_node(&cic->rb_node, parent, p); - rb_insert_color(&cic->rb_node, &ioc->cic_root); + if (ret) + printk(KERN_ERR "cfq: cic link failed!\n"); - spin_lock_irqsave(cfqd->queue->queue_lock, flags); - list_add(&cic->queue_list, &cfqd->cic_list); - spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); + return ret; } /* @@ -1527,7 +1660,7 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) if (!ioc) return NULL; - cic = cfq_cic_rb_lookup(cfqd, ioc); + cic = cfq_cic_lookup(cfqd, ioc); if (cic) goto out; @@ -1535,13 +1668,17 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) if (cic == NULL) goto err; - cfq_cic_link(cfqd, ioc, cic); + if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) + goto err_free; + out: smp_read_barrier_depends(); if (unlikely(ioc->ioprio_changed)) cfq_ioc_set_ioprio(ioc); return cic; +err_free: + cfq_cic_free(cic); err: put_io_context(ioc); return NULL; @@ -1570,11 +1707,6 @@ cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, else sdist = cic->last_request_pos - rq->sector; - if (!cic->seek_samples) { - cfqd->new_seek_total = (7*cic->seek_total + (u64)256*sdist) / 8; - cfqd->new_seek_mean = cfqd->new_seek_total / 256; - } - /* * Don't allow the seek distance to get too large from the * odd fragment, pagein, etc @@ -1599,14 +1731,17 @@ static void cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, struct cfq_io_context *cic) { - int enable_idle; + int old_idle, enable_idle; - if (!cfq_cfqq_sync(cfqq)) + /* + * Don't idle for async or idle io prio class + */ + if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) return; - enable_idle = cfq_cfqq_idle_window(cfqq); + enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); - if (!cic->ioc->task || !cfqd->cfq_slice_idle || + if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || (cfqd->hw_tag && CIC_SEEKY(cic))) enable_idle = 0; else if (sample_valid(cic->ttime_samples)) { @@ -1616,10 +1751,13 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, enable_idle = 1; } - if (enable_idle) - cfq_mark_cfqq_idle_window(cfqq); - else - cfq_clear_cfqq_idle_window(cfqq); + if (old_idle != enable_idle) { + cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); + if (enable_idle) + cfq_mark_cfqq_idle_window(cfqq); + else + cfq_clear_cfqq_idle_window(cfqq); + } } /* @@ -1678,6 +1816,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, */ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) { + cfq_log_cfqq(cfqd, cfqq, "preempt"); cfq_slice_expired(cfqd, 1); /* @@ -1702,6 +1841,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, { struct cfq_io_context *cic = RQ_CIC(rq); + cfqd->rq_queued++; if (rq_is_meta(rq)) cfqq->meta_pending++; @@ -1710,7 +1850,6 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfq_update_idle_window(cfqd, cfqq, cic); cic->last_request_pos = rq->sector + rq->nr_sectors; - cfqq->last_request_pos = cic->last_request_pos; if (cfqq == cfqd->active_queue) { /* @@ -1735,12 +1874,13 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, } } -static void cfq_insert_request(request_queue_t *q, struct request *rq) +static void cfq_insert_request(struct request_queue *q, struct request *rq) { struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_queue *cfqq = RQ_CFQQ(rq); - cfq_init_prio_data(cfqq); + cfq_log_cfqq(cfqd, cfqq, "insert_request"); + cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); cfq_add_rq_rb(rq); @@ -1749,7 +1889,32 @@ static void cfq_insert_request(request_queue_t *q, struct request *rq) cfq_rq_enqueued(cfqd, cfqq, rq); } -static void cfq_completed_request(request_queue_t *q, struct request *rq) +/* + * Update hw_tag based on peak queue depth over 50 samples under + * sufficient load. + */ +static void cfq_update_hw_tag(struct cfq_data *cfqd) +{ + if (cfqd->rq_in_driver > cfqd->rq_in_driver_peak) + cfqd->rq_in_driver_peak = cfqd->rq_in_driver; + + if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && + cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) + return; + + if (cfqd->hw_tag_samples++ < 50) + return; + + if (cfqd->rq_in_driver_peak >= CFQ_HW_QUEUE_MIN) + cfqd->hw_tag = 1; + else + cfqd->hw_tag = 0; + + cfqd->hw_tag_samples = 0; + cfqd->rq_in_driver_peak = 0; +} + +static void cfq_completed_request(struct request_queue *q, struct request *rq) { struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_data *cfqd = cfqq->cfqd; @@ -1757,6 +1922,9 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq) unsigned long now; now = jiffies; + cfq_log_cfqq(cfqd, cfqq, "complete"); + + cfq_update_hw_tag(cfqd); WARN_ON(!cfqd->rq_in_driver); WARN_ON(!cfqq->dispatched); @@ -1781,7 +1949,7 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq) cfq_set_prio_slice(cfqd, cfqq); cfq_clear_cfqq_slice_new(cfqq); } - if (cfq_slice_used(cfqq)) + if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) cfq_slice_expired(cfqd, 1); else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list)) cfq_arm_slice_timer(cfqd); @@ -1828,7 +1996,7 @@ static inline int __cfq_may_queue(struct cfq_queue *cfqq) return ELV_MQUEUE_MAY; } -static int cfq_may_queue(request_queue_t *q, int rw) +static int cfq_may_queue(struct request_queue *q, int rw) { struct cfq_data *cfqd = q->elevator->elevator_data; struct task_struct *tsk = current; @@ -1841,13 +2009,13 @@ static int cfq_may_queue(request_queue_t *q, int rw) * so just lookup a possibly existing queue, or return 'may queue' * if that fails */ - cic = cfq_cic_rb_lookup(cfqd, tsk->io_context); + cic = cfq_cic_lookup(cfqd, tsk->io_context); if (!cic) return ELV_MQUEUE_MAY; cfqq = cic_to_cfqq(cic, rw & REQ_RW_SYNC); if (cfqq) { - cfq_init_prio_data(cfqq); + cfq_init_prio_data(cfqq, cic->ioc); cfq_prio_boost(cfqq); return __cfq_may_queue(cfqq); @@ -1882,10 +2050,9 @@ static void cfq_put_request(struct request *rq) * Allocate cfq data structures associated with this request. */ static int -cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask) +cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) { struct cfq_data *cfqd = q->elevator->elevator_data; - struct task_struct *tsk = current; struct cfq_io_context *cic; const int rw = rq_data_dir(rq); const int is_sync = rq_is_sync(rq); @@ -1903,7 +2070,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask) cfqq = cic_to_cfqq(cic, is_sync); if (!cfqq) { - cfqq = cfq_get_queue(cfqd, is_sync, tsk, gfp_mask); + cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); if (!cfqq) goto queue_fail; @@ -1927,6 +2094,7 @@ queue_fail: cfq_schedule_dispatch(cfqd); spin_unlock_irqrestore(q->queue_lock, flags); + cfq_log(cfqd, "set_request fail"); return 1; } @@ -1934,7 +2102,7 @@ static void cfq_kick_queue(struct work_struct *work) { struct cfq_data *cfqd = container_of(work, struct cfq_data, unplug_work); - request_queue_t *q = cfqd->queue; + struct request_queue *q = cfqd->queue; unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); @@ -1952,9 +2120,12 @@ static void cfq_idle_slice_timer(unsigned long data) unsigned long flags; int timed_out = 1; + cfq_log(cfqd, "idle timer fired"); + spin_lock_irqsave(cfqd->queue->queue_lock, flags); - if ((cfqq = cfqd->active_queue) != NULL) { + cfqq = cfqd->active_queue; + if (cfqq) { timed_out = 0; /* @@ -1986,39 +2157,31 @@ out_cont: spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); } -/* - * Timer running if an idle class queue is waiting for service - */ -static void cfq_idle_class_timer(unsigned long data) +static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) { - struct cfq_data *cfqd = (struct cfq_data *) data; - unsigned long flags, end; - - spin_lock_irqsave(cfqd->queue->queue_lock, flags); - - /* - * race with a non-idle queue, reset timer - */ - end = cfqd->last_end_request + CFQ_IDLE_GRACE; - if (!time_after_eq(jiffies, end)) - mod_timer(&cfqd->idle_class_timer, end); - else - cfq_schedule_dispatch(cfqd); - - spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); + del_timer_sync(&cfqd->idle_slice_timer); + kblockd_flush_work(&cfqd->unplug_work); } -static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) +static void cfq_put_async_queues(struct cfq_data *cfqd) { - del_timer_sync(&cfqd->idle_slice_timer); - del_timer_sync(&cfqd->idle_class_timer); - blk_sync_queue(cfqd->queue); + int i; + + for (i = 0; i < IOPRIO_BE_NR; i++) { + if (cfqd->async_cfqq[0][i]) + cfq_put_queue(cfqd->async_cfqq[0][i]); + if (cfqd->async_cfqq[1][i]) + cfq_put_queue(cfqd->async_cfqq[1][i]); + } + + if (cfqd->async_idle_cfqq) + cfq_put_queue(cfqd->async_idle_cfqq); } static void cfq_exit_queue(elevator_t *e) { struct cfq_data *cfqd = e->elevator_data; - request_queue_t *q = cfqd->queue; + struct request_queue *q = cfqd->queue; cfq_shutdown_timer_wq(cfqd); @@ -2035,6 +2198,8 @@ static void cfq_exit_queue(elevator_t *e) __cfq_exit_single_io_context(cfqd, cic); } + cfq_put_async_queues(cfqd); + spin_unlock_irq(q->queue_lock); cfq_shutdown_timer_wq(cfqd); @@ -2042,16 +2207,14 @@ static void cfq_exit_queue(elevator_t *e) kfree(cfqd); } -static void *cfq_init_queue(request_queue_t *q) +static void *cfq_init_queue(struct request_queue *q) { struct cfq_data *cfqd; - cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node); + cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); if (!cfqd) return NULL; - memset(cfqd, 0, sizeof(*cfqd)); - cfqd->service_tree = CFQ_RB_ROOT; INIT_LIST_HEAD(&cfqd->cic_list); @@ -2061,12 +2224,9 @@ static void *cfq_init_queue(request_queue_t *q) cfqd->idle_slice_timer.function = cfq_idle_slice_timer; cfqd->idle_slice_timer.data = (unsigned long) cfqd; - init_timer(&cfqd->idle_class_timer); - cfqd->idle_class_timer.function = cfq_idle_class_timer; - cfqd->idle_class_timer.data = (unsigned long) cfqd; - INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); + cfqd->last_end_request = jiffies; cfqd->cfq_quantum = cfq_quantum; cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; @@ -2076,12 +2236,17 @@ static void *cfq_init_queue(request_queue_t *q) cfqd->cfq_slice[1] = cfq_slice_sync; cfqd->cfq_slice_async_rq = cfq_slice_async_rq; cfqd->cfq_slice_idle = cfq_slice_idle; + cfqd->hw_tag = 1; return cfqd; } static void cfq_slab_kill(void) { + /* + * Caller already ensured that pending RCU callbacks are completed, + * so we should have no busy allocations at this point. + */ if (cfq_pool) kmem_cache_destroy(cfq_pool); if (cfq_ioc_pool) @@ -2159,14 +2324,18 @@ static ssize_t __FUNC(elevator_t *e, const char *page, size_t count) \ return ret; \ } STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); -STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, UINT_MAX, 1); -STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, UINT_MAX, 1); +STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, + UINT_MAX, 1); +STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, + UINT_MAX, 1); STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0); -STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, UINT_MAX, 0); +STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, + UINT_MAX, 0); STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); -STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, UINT_MAX, 0); +STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, + UINT_MAX, 0); #undef STORE_FUNCTION #define CFQ_ATTR(name) \ @@ -2213,8 +2382,6 @@ static struct elevator_type iosched_cfq = { static int __init cfq_init(void) { - int ret; - /* * could be 0 on HZ < 1000 setups */ @@ -2226,11 +2393,9 @@ static int __init cfq_init(void) if (cfq_slab_setup()) return -ENOMEM; - ret = elv_register(&iosched_cfq); - if (ret) - cfq_slab_kill(); + elv_register(&iosched_cfq); - return ret; + return 0; } static void __exit cfq_exit(void) @@ -2240,9 +2405,13 @@ static void __exit cfq_exit(void) ioc_gone = &all_gone; /* ioc_gone's update must be visible before reading ioc_count */ smp_wmb(); + + /* + * this also protects us from entering cfq_slab_kill() with + * pending RCU callbacks + */ if (elv_ioc_count_read(ioc_count)) - wait_for_completion(ioc_gone); - synchronize_rcu(); + wait_for_completion(&all_gone); cfq_slab_kill(); }