X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=blobdiff_plain;f=block%2Fcfq-iosched.c;h=0f962ecae91fb68345fe1d916791a78e06a2f2e8;hp=8830893e062ff901793cb7616f412fbc317be489;hb=16d3be46d9ffbc2c562b25d66d59666db2cf2cd5;hpb=4ac845a2e9a816ed5a7b301f56dcc0a3d0b1ba4d diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 8830893e062f..0f962ecae91f 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -15,20 +15,22 @@ /* * 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 @@ -37,7 +39,8 @@ static int cfq_slice_idle = HZ / 125; #define CFQ_SLICE_SCALE (5) -#define RQ_CIC(rq) ((struct cfq_io_context*)(rq)->elevator_private) +#define RQ_CIC(rq) \ + ((struct cfq_io_context *) (rq)->elevator_private) #define RQ_CFQQ(rq) ((rq)->elevator_private2) static struct kmem_cache *cfq_pool; @@ -98,8 +101,6 @@ struct cfq_data { struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; struct cfq_queue *async_idle_cfqq; - struct timer_list idle_class_timer; - sector_t last_position; unsigned long last_end_request; @@ -173,15 +174,15 @@ 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); @@ -384,12 +385,15 @@ 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) @@ -446,12 +450,20 @@ 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; @@ -469,8 +481,9 @@ 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; @@ -524,8 +537,7 @@ 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) { BUG_ON(cfq_cfqq_on_rr(cfqq)); cfq_mark_cfqq_on_rr(cfqq); @@ -538,8 +550,7 @@ 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) { BUG_ON(!cfq_cfqq_on_rr(cfqq)); cfq_clear_cfqq_on_rr(cfqq); @@ -554,7 +565,7 @@ 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; @@ -594,8 +605,7 @@ 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)]--; @@ -732,15 +742,10 @@ static int cfq_allow_merge(struct request_queue *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); - cfqq->slice_end = 0; cfq_clear_cfqq_must_alloc_slice(cfqq); cfq_clear_cfqq_fifo_expire(cfqq); @@ -789,47 +794,16 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out) __cfq_slice_expired(cfqd, cfqq, timed_out); } -static int start_idle_class_timer(struct cfq_data *cfqd) -{ - unsigned long end = cfqd->last_end_request + CFQ_IDLE_GRACE; - unsigned long now = jiffies; - - if (time_before(now, end) && - time_after_eq(now, cfqd->last_end_request)) { - mod_timer(&cfqd->idle_class_timer, end); - return 1; - } - - return 0; -} - /* * Get next queue for service. Unless we have a queue preemption, * we'll simply select the first cfqq in the service tree. */ 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)) { - /* - * 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 - */ - if (start_idle_class_timer(cfqd)) - cfqq = NULL; - } - - return cfqq; + return cfq_rb_first(&cfqd->service_tree); } /* @@ -939,7 +913,7 @@ static void cfq_dispatch_insert(struct request_queue *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; @@ -1034,7 +1008,8 @@ __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; /* @@ -1068,7 +1043,7 @@ __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; @@ -1087,14 +1062,11 @@ 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); @@ -1173,38 +1145,19 @@ static void cfq_put_queue(struct cfq_queue *cfqq) /* * Call func for each cic attached to this ioc. Returns number of cic's seen. */ -#define CIC_GANG_NR 16 static unsigned int call_for_each_cic(struct io_context *ioc, void (*func)(struct io_context *, struct cfq_io_context *)) { - struct cfq_io_context *cics[CIC_GANG_NR]; - unsigned long index = 0; - unsigned int called = 0; - int nr; + struct cfq_io_context *cic; + struct hlist_node *n; + int called = 0; rcu_read_lock(); - - do { - int i; - - /* - * Perhaps there's a better way - this just gang lookups from - * 0 to the end, restarting after each CIC_GANG_NR from the - * last key + 1. - */ - nr = radix_tree_gang_lookup(&ioc->radix_root, (void **) cics, - index, CIC_GANG_NR); - if (!nr) - break; - - called += nr; - index = 1 + (unsigned long) cics[nr - 1]->key; - - for (i = 0; i < nr; i++) - func(ioc, cics[i]); - } while (nr == CIC_GANG_NR); - + hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) { + func(ioc, cic); + called++; + } rcu_read_unlock(); return called; @@ -1218,6 +1171,7 @@ static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) 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); kmem_cache_free(cfq_ioc_pool, cic); @@ -1308,6 +1262,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) if (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); @@ -1326,28 +1281,28 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) 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(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; + 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(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; } /* @@ -1359,8 +1314,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) cfq_clear_cfqq_prio_changed(cfqq); } -static inline void changed_ioprio(struct io_context *ioc, - 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; @@ -1437,15 +1391,16 @@ retry: 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, ioc); + + if (is_sync) { + if (!cfq_class_idle(cfqq)) + cfq_mark_cfqq_idle_window(cfqq); + cfq_mark_cfqq_sync(cfqq); + } } if (new_cfqq) @@ -1459,7 +1414,7 @@ out: static struct cfq_queue ** cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) { - switch(ioprio_class) { + switch (ioprio_class) { case IOPRIO_CLASS_RT: return &cfqd->async_cfqq[0][ioprio]; case IOPRIO_CLASS_BE: @@ -1529,6 +1484,7 @@ cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, rcu_assign_pointer(ioc->ioc_data, NULL); 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); @@ -1575,9 +1531,8 @@ cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) * 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 inline int -cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, - struct cfq_io_context *cic, gfp_t gfp_mask) +static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, + struct cfq_io_context *cic, gfp_t gfp_mask) { unsigned long flags; int ret; @@ -1590,6 +1545,8 @@ cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, 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); radix_tree_preload_end(); @@ -1697,7 +1654,10 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, { int 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); @@ -1876,7 +1836,7 @@ static void cfq_completed_request(struct request_queue *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); @@ -2048,7 +2008,8 @@ static void cfq_idle_slice_timer(unsigned long data) spin_lock_irqsave(cfqd->queue->queue_lock, flags); - if ((cfqq = cfqd->active_queue) != NULL) { + cfqq = cfqd->active_queue; + if (cfqq) { timed_out = 0; /* @@ -2080,29 +2041,9 @@ 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) -{ - struct cfq_data *cfqd = (struct cfq_data *) data; - unsigned long flags; - - spin_lock_irqsave(cfqd->queue->queue_lock, flags); - - /* - * race with a non-idle queue, reset timer - */ - if (!start_idle_class_timer(cfqd)) - cfq_schedule_dispatch(cfqd); - - spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); -} - static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) { del_timer_sync(&cfqd->idle_slice_timer); - del_timer_sync(&cfqd->idle_class_timer); kblockd_flush_work(&cfqd->unplug_work); } @@ -2167,10 +2108,6 @@ 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_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; @@ -2266,14 +2203,18 @@ 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) \