From 5e705374796e72b36e7bb9c59c8d46d2dc5db36a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 13 Jul 2006 12:39:25 +0200 Subject: [PATCH] cfq-iosched: kill crq Get rid of the cfq_rq request type. With the added elevator_private2, we have enough room in struct request to get rid of any crq allocation/free for each request. Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 239 +++++++++++++++++++++------------------------------- 1 file changed, 95 insertions(+), 144 deletions(-) (limited to 'block') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 86f0f4796fd..3c5fd9c2c20 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -43,9 +43,9 @@ static DEFINE_SPINLOCK(cfq_exit_lock); #define list_entry_cfqq(ptr) list_entry((ptr), struct cfq_queue, cfq_list) -#define RQ_DATA(rq) (rq)->elevator_private +#define RQ_CIC(rq) ((struct cfq_io_context*)(rq)->elevator_private) +#define RQ_CFQQ(rq) ((rq)->elevator_private2) -static kmem_cache_t *crq_pool; static kmem_cache_t *cfq_pool; static kmem_cache_t *cfq_ioc_pool; @@ -95,8 +95,6 @@ struct cfq_data { */ struct hlist_head *cfq_hash; - mempool_t *crq_pool; - int rq_in_driver; int hw_tag; @@ -153,7 +151,7 @@ struct cfq_queue { /* sorted list of pending requests */ struct rb_root sort_list; /* if fifo isn't expired, next request to serve */ - struct cfq_rq *next_crq; + struct request *next_rq; /* requests queued in sort_list */ int queued[2]; /* currently allocated requests */ @@ -177,13 +175,6 @@ struct cfq_queue { unsigned int flags; }; -struct cfq_rq { - struct request *request; - - struct cfq_queue *cfq_queue; - struct cfq_io_context *io_context; -}; - enum cfqq_state_flags { CFQ_CFQQ_FLAG_on_rr = 0, CFQ_CFQQ_FLAG_wait_request, @@ -220,7 +211,7 @@ CFQ_CFQQ_FNS(prio_changed); #undef CFQ_CFQQ_FNS static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short); -static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *); +static void cfq_dispatch_insert(request_queue_t *, struct request *); static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, gfp_t gfp_mask); /* @@ -249,12 +240,12 @@ static inline pid_t cfq_queue_pid(struct task_struct *task, int rw) } /* - * Lifted from AS - choose which of crq1 and crq2 that is best served now. + * Lifted from AS - choose which of rq1 and rq2 that is best served now. * We choose the request that is closest to the head right now. Distance * behind the head is penalized and only allowed to a certain extent. */ -static struct cfq_rq * -cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2) +static struct request * +cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2) { sector_t last, s1, s2, d1 = 0, d2 = 0; unsigned long back_max; @@ -262,18 +253,18 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2) #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ unsigned wrap = 0; /* bit mask: requests behind the disk head? */ - if (crq1 == NULL || crq1 == crq2) - return crq2; - if (crq2 == NULL) - return crq1; + if (rq1 == NULL || rq1 == rq2) + return rq2; + if (rq2 == NULL) + return rq1; - if (rq_is_sync(crq1->request) && !rq_is_sync(crq2->request)) - return crq1; - else if (rq_is_sync(crq2->request) && !rq_is_sync(crq1->request)) - return crq2; + if (rq_is_sync(rq1) && !rq_is_sync(rq2)) + return rq1; + else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) + return rq2; - s1 = crq1->request->sector; - s2 = crq2->request->sector; + s1 = rq1->sector; + s2 = rq2->sector; last = cfqd->last_sector; @@ -308,23 +299,23 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2) * check two variables for all permutations: --> faster! */ switch (wrap) { - case 0: /* common case for CFQ: crq1 and crq2 not wrapped */ + case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ if (d1 < d2) - return crq1; + return rq1; else if (d2 < d1) - return crq2; + return rq2; else { if (s1 >= s2) - return crq1; + return rq1; else - return crq2; + return rq2; } case CFQ_RQ2_WRAP: - return crq1; + return rq1; case CFQ_RQ1_WRAP: - return crq2; - case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both crqs wrapped */ + return rq2; + case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ default: /* * Since both rqs are wrapped, @@ -333,35 +324,34 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2) * since back seek takes more time than forward. */ if (s1 <= s2) - return crq1; + return rq1; else - return crq2; + return rq2; } } /* * would be nice to take fifo expire time into account as well */ -static struct cfq_rq * -cfq_find_next_crq(struct cfq_data *cfqd, struct cfq_queue *cfqq, - struct cfq_rq *last_crq) +static struct request * +cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, + struct request *last) { - struct request *last = last_crq->request; struct rb_node *rbnext = rb_next(&last->rb_node); struct rb_node *rbprev = rb_prev(&last->rb_node); - struct cfq_rq *next = NULL, *prev = NULL; + struct request *next = NULL, *prev = NULL; BUG_ON(RB_EMPTY_NODE(&last->rb_node)); if (rbprev) - prev = RQ_DATA(rb_entry_rq(rbprev)); + prev = rb_entry_rq(rbprev); if (rbnext) - next = RQ_DATA(rb_entry_rq(rbnext)); + next = rb_entry_rq(rbnext); else { rbnext = rb_first(&cfqq->sort_list); if (rbnext && rbnext != &last->rb_node) - next = RQ_DATA(rb_entry_rq(rbnext)); + next = rb_entry_rq(rbnext); } return cfq_choose_req(cfqd, next, prev); @@ -450,26 +440,25 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) /* * rb tree support functions */ -static inline void cfq_del_crq_rb(struct cfq_rq *crq) +static inline void cfq_del_rq_rb(struct request *rq) { - struct cfq_queue *cfqq = crq->cfq_queue; + struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_data *cfqd = cfqq->cfqd; - const int sync = rq_is_sync(crq->request); + const int sync = rq_is_sync(rq); BUG_ON(!cfqq->queued[sync]); cfqq->queued[sync]--; - elv_rb_del(&cfqq->sort_list, crq->request); + elv_rb_del(&cfqq->sort_list, rq); if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) cfq_del_cfqq_rr(cfqd, cfqq); } -static void cfq_add_crq_rb(struct cfq_rq *crq) +static void cfq_add_rq_rb(struct request *rq) { - struct cfq_queue *cfqq = crq->cfq_queue; + struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_data *cfqd = cfqq->cfqd; - struct request *rq = crq->request; struct request *__alias; cfqq->queued[rq_is_sync(rq)]++; @@ -479,17 +468,15 @@ static void cfq_add_crq_rb(struct cfq_rq *crq) * if that happens, put the alias on the dispatch list */ while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) - cfq_dispatch_insert(cfqd->queue, RQ_DATA(__alias)); + cfq_dispatch_insert(cfqd->queue, __alias); } static inline void -cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq) +cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) { - struct request *rq = crq->request; - elv_rb_del(&cfqq->sort_list, rq); cfqq->queued[rq_is_sync(rq)]--; - cfq_add_crq_rb(crq); + cfq_add_rq_rb(rq); } static struct request * @@ -533,14 +520,13 @@ static void cfq_deactivate_request(request_queue_t *q, struct request *rq) static void cfq_remove_request(struct request *rq) { - struct cfq_rq *crq = RQ_DATA(rq); - struct cfq_queue *cfqq = crq->cfq_queue; + struct cfq_queue *cfqq = RQ_CFQQ(rq); - if (cfqq->next_crq == crq) - cfqq->next_crq = cfq_find_next_crq(cfqq->cfqd, cfqq, crq); + if (cfqq->next_rq == rq) + cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); list_del_init(&rq->queuelist); - cfq_del_crq_rb(crq); + cfq_del_rq_rb(rq); } static int @@ -561,12 +547,10 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio) static void cfq_merged_request(request_queue_t *q, struct request *req, int type) { - struct cfq_rq *crq = RQ_DATA(req); - if (type == ELEVATOR_FRONT_MERGE) { - struct cfq_queue *cfqq = crq->cfq_queue; + struct cfq_queue *cfqq = RQ_CFQQ(req); - cfq_reposition_crq_rb(cfqq, crq); + cfq_reposition_rq_rb(cfqq, req); } } @@ -789,11 +773,10 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) return 1; } -static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq) +static void cfq_dispatch_insert(request_queue_t *q, struct request *rq) { struct cfq_data *cfqd = q->elevator->elevator_data; - struct cfq_queue *cfqq = crq->cfq_queue; - struct request *rq = crq->request; + struct cfq_queue *cfqq = RQ_CFQQ(rq); cfq_remove_request(rq); cfqq->on_dispatch[rq_is_sync(rq)]++; @@ -806,11 +789,10 @@ static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq) /* * return expired entry, or NULL to just start from scratch in rbtree */ -static inline struct cfq_rq *cfq_check_fifo(struct cfq_queue *cfqq) +static inline struct request *cfq_check_fifo(struct cfq_queue *cfqq) { struct cfq_data *cfqd = cfqq->cfqd; struct request *rq; - struct cfq_rq *crq; if (cfq_cfqq_fifo_expire(cfqq)) return NULL; @@ -818,11 +800,10 @@ static inline struct cfq_rq *cfq_check_fifo(struct cfq_queue *cfqq) if (!list_empty(&cfqq->fifo)) { int fifo = cfq_cfqq_class_sync(cfqq); - crq = RQ_DATA(rq_entry_fifo(cfqq->fifo.next)); - rq = crq->request; + rq = rq_entry_fifo(cfqq->fifo.next); if (time_after(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) { cfq_mark_cfqq_fifo_expire(cfqq); - return crq; + return rq; } } @@ -909,25 +890,25 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq, BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); do { - struct cfq_rq *crq; + struct request *rq; /* * follow expired path, else get first next available */ - if ((crq = cfq_check_fifo(cfqq)) == NULL) - crq = cfqq->next_crq; + if ((rq = cfq_check_fifo(cfqq)) == NULL) + rq = cfqq->next_rq; /* * finally, insert request into driver dispatch list */ - cfq_dispatch_insert(cfqd->queue, crq); + cfq_dispatch_insert(cfqd->queue, rq); cfqd->dispatch_slice++; dispatched++; if (!cfqd->active_cic) { - atomic_inc(&crq->io_context->ioc->refcount); - cfqd->active_cic = crq->io_context; + atomic_inc(&RQ_CIC(rq)->ioc->refcount); + cfqd->active_cic = RQ_CIC(rq); } if (RB_EMPTY_ROOT(&cfqq->sort_list)) @@ -958,13 +939,12 @@ static int cfq_forced_dispatch_cfqqs(struct list_head *list) { struct cfq_queue *cfqq, *next; - struct cfq_rq *crq; int dispatched; dispatched = 0; list_for_each_entry_safe(cfqq, next, list, cfq_list) { - while ((crq = cfqq->next_crq)) { - cfq_dispatch_insert(cfqq->cfqd->queue, crq); + while (cfqq->next_rq) { + cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); dispatched++; } BUG_ON(!list_empty(&cfqq->fifo)); @@ -1040,8 +1020,8 @@ cfq_dispatch_requests(request_queue_t *q, int force) } /* - * task holds one reference to the queue, dropped when task exits. each crq - * in-flight on this queue also holds a reference, dropped when crq is freed. + * task holds one reference to the queue, dropped when task exits. each rq + * in-flight on this queue also holds a reference, dropped when rq is freed. * * queue lock must be held here. */ @@ -1486,15 +1466,15 @@ cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) static void cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, - struct cfq_rq *crq) + struct request *rq) { sector_t sdist; u64 total; - if (cic->last_request_pos < crq->request->sector) - sdist = crq->request->sector - cic->last_request_pos; + if (cic->last_request_pos < rq->sector) + sdist = rq->sector - cic->last_request_pos; else - sdist = cic->last_request_pos - crq->request->sector; + sdist = cic->last_request_pos - rq->sector; /* * Don't allow the seek distance to get too large from the @@ -1545,7 +1525,7 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, */ static int cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, - struct cfq_rq *crq) + struct request *rq) { struct cfq_queue *cfqq = cfqd->active_queue; @@ -1564,7 +1544,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, */ if (new_cfqq->slice_left < cfqd->cfq_slice_idle) return 0; - if (rq_is_sync(crq->request) && !cfq_cfqq_sync(cfqq)) + if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) return 1; return 0; @@ -1603,26 +1583,26 @@ static void cfq_start_queueing(struct cfq_data *cfqd, struct cfq_queue *cfqq) } /* - * Called when a new fs request (crq) is added (to cfqq). Check if there's + * Called when a new fs request (rq) is added (to cfqq). Check if there's * something we should do about it */ static void -cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, - struct cfq_rq *crq) +cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, + struct request *rq) { - struct cfq_io_context *cic = crq->io_context; + struct cfq_io_context *cic = RQ_CIC(rq); /* * check if this request is a better next-serve candidate)) { */ - cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq); - BUG_ON(!cfqq->next_crq); + cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq); + BUG_ON(!cfqq->next_rq); /* * we never wait for an async request and we don't allow preemption * of an async request. so just return early */ - if (!rq_is_sync(crq->request)) { + if (!rq_is_sync(rq)) { /* * sync process issued an async request, if it's waiting * then expire it and kick rq handling. @@ -1636,11 +1616,11 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, } cfq_update_io_thinktime(cfqd, cic); - cfq_update_io_seektime(cfqd, cic, crq); + cfq_update_io_seektime(cfqd, cic, rq); cfq_update_idle_window(cfqd, cfqq, cic); cic->last_queue = jiffies; - cic->last_request_pos = crq->request->sector + crq->request->nr_sectors; + cic->last_request_pos = rq->sector + rq->nr_sectors; if (cfqq == cfqd->active_queue) { /* @@ -1653,7 +1633,7 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, del_timer(&cfqd->idle_slice_timer); cfq_start_queueing(cfqd, cfqq); } - } else if (cfq_should_preempt(cfqd, cfqq, crq)) { + } else if (cfq_should_preempt(cfqd, cfqq, rq)) { /* * not the active queue - expire current slice if it is * idle and has expired it's mean thinktime or this new queue @@ -1668,25 +1648,23 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, static void cfq_insert_request(request_queue_t *q, struct request *rq) { struct cfq_data *cfqd = q->elevator->elevator_data; - struct cfq_rq *crq = RQ_DATA(rq); - struct cfq_queue *cfqq = crq->cfq_queue; + struct cfq_queue *cfqq = RQ_CFQQ(rq); cfq_init_prio_data(cfqq); - cfq_add_crq_rb(crq); + cfq_add_rq_rb(rq); if (!cfq_cfqq_on_rr(cfqq)) cfq_add_cfqq_rr(cfqd, cfqq); list_add_tail(&rq->queuelist, &cfqq->fifo); - cfq_crq_enqueued(cfqd, cfqq, crq); + cfq_rq_enqueued(cfqd, cfqq, rq); } static void cfq_completed_request(request_queue_t *q, struct request *rq) { - struct cfq_rq *crq = RQ_DATA(rq); - struct cfq_queue *cfqq = crq->cfq_queue; + struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_data *cfqd = cfqq->cfqd; const int sync = rq_is_sync(rq); unsigned long now; @@ -1709,7 +1687,7 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq) } if (sync) - crq->io_context->last_end_request = now; + RQ_CIC(rq)->last_end_request = now; /* * If this is the active queue, check if it needs to be expired, @@ -1817,20 +1795,18 @@ static void cfq_check_waiters(request_queue_t *q, struct cfq_queue *cfqq) */ static void cfq_put_request(request_queue_t *q, struct request *rq) { - struct cfq_data *cfqd = q->elevator->elevator_data; - struct cfq_rq *crq = RQ_DATA(rq); + struct cfq_queue *cfqq = RQ_CFQQ(rq); - if (crq) { - struct cfq_queue *cfqq = crq->cfq_queue; + if (cfqq) { const int rw = rq_data_dir(rq); BUG_ON(!cfqq->allocated[rw]); cfqq->allocated[rw]--; - put_io_context(crq->io_context->ioc); + put_io_context(RQ_CIC(rq)->ioc); - mempool_free(crq, cfqd->crq_pool); rq->elevator_private = NULL; + rq->elevator_private2 = NULL; cfq_check_waiters(q, cfqq); cfq_put_queue(cfqq); @@ -1850,7 +1826,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio, const int rw = rq_data_dir(rq); pid_t key = cfq_queue_pid(tsk, rw); struct cfq_queue *cfqq; - struct cfq_rq *crq; unsigned long flags; int is_sync = key != CFQ_KEY_ASYNC; @@ -1876,23 +1851,13 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio, cfq_clear_cfqq_must_alloc(cfqq); cfqd->rq_starved = 0; atomic_inc(&cfqq->ref); - spin_unlock_irqrestore(q->queue_lock, flags); - crq = mempool_alloc(cfqd->crq_pool, gfp_mask); - if (crq) { - crq->request = rq; - crq->cfq_queue = cfqq; - crq->io_context = cic; + spin_unlock_irqrestore(q->queue_lock, flags); - rq->elevator_private = crq; - return 0; - } + rq->elevator_private = cic; + rq->elevator_private2 = cfqq; + return 0; - spin_lock_irqsave(q->queue_lock, flags); - cfqq->allocated[rw]--; - if (!(cfqq->allocated[0] + cfqq->allocated[1])) - cfq_mark_cfqq_must_alloc(cfqq); - cfq_put_queue(cfqq); queue_fail: if (cic) put_io_context(cic->ioc); @@ -2040,7 +2005,6 @@ static void cfq_exit_queue(elevator_t *e) cfq_shutdown_timer_wq(cfqd); - mempool_destroy(cfqd->crq_pool); kfree(cfqd->cfq_hash); kfree(cfqd); } @@ -2067,11 +2031,7 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e) cfqd->cfq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL); if (!cfqd->cfq_hash) - goto out_crqhash; - - cfqd->crq_pool = mempool_create_slab_pool(BLKDEV_MIN_RQ, crq_pool); - if (!cfqd->crq_pool) - goto out_crqpool; + goto out_free; for (i = 0; i < CFQ_QHASH_ENTRIES; i++) INIT_HLIST_HEAD(&cfqd->cfq_hash[i]); @@ -2100,17 +2060,13 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e) cfqd->cfq_slice_idle = cfq_slice_idle; return cfqd; -out_crqpool: - kfree(cfqd->cfq_hash); -out_crqhash: +out_free: kfree(cfqd); return NULL; } static void cfq_slab_kill(void) { - if (crq_pool) - kmem_cache_destroy(crq_pool); if (cfq_pool) kmem_cache_destroy(cfq_pool); if (cfq_ioc_pool) @@ -2119,11 +2075,6 @@ static void cfq_slab_kill(void) static int __init cfq_slab_setup(void) { - crq_pool = kmem_cache_create("crq_pool", sizeof(struct cfq_rq), 0, 0, - NULL, NULL); - if (!crq_pool) - goto fail; - cfq_pool = kmem_cache_create("cfq_pool", sizeof(struct cfq_queue), 0, 0, NULL, NULL); if (!cfq_pool) -- cgit v1.2.3