Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758920AbZFSUjs (ORCPT ); Fri, 19 Jun 2009 16:39:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755514AbZFSUiv (ORCPT ); Fri, 19 Jun 2009 16:38:51 -0400 Received: from mx2.redhat.com ([66.187.237.31]:56587 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756803AbZFSUiq (ORCPT ); Fri, 19 Jun 2009 16:38:46 -0400 From: Vivek Goyal To: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, dm-devel@redhat.com, jens.axboe@oracle.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, ryov@valinux.co.jp, fernando@oss.ntt.co.jp, s-uchida@ap.jp.nec.com, taka@valinux.co.jp, guijianfeng@cn.fujitsu.com, jmoyer@redhat.com, dhaval@linux.vnet.ibm.com, balbir@linux.vnet.ibm.com, righi.andrea@gmail.com, m-ikeda@ds.jp.nec.com, jbaron@redhat.com Cc: agk@redhat.com, snitzer@redhat.com, vgoyal@redhat.com, akpm@linux-foundation.org, peterz@infradead.org Subject: [PATCH 04/20] io-controller: Modify cfq to make use of flat elevator fair queuing Date: Fri, 19 Jun 2009 16:37:22 -0400 Message-Id: <1245443858-8487-5-git-send-email-vgoyal@redhat.com> In-Reply-To: <1245443858-8487-1-git-send-email-vgoyal@redhat.com> References: <1245443858-8487-1-git-send-email-vgoyal@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 54189 Lines: 1876 This patch changes cfq to use fair queuing code from elevator layer. Signed-off-by: Nauman Rafique Signed-off-by: Fabio Checconi Signed-off-by: Paolo Valente Signed-off-by: Gui Jianfeng Signed-off-by: Vivek Goyal --- block/Kconfig.iosched | 3 +- block/cfq-iosched.c | 1106 +++++++++------------------------------------ include/linux/iocontext.h | 5 - 3 files changed, 222 insertions(+), 892 deletions(-) diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched index 3398134..dd5224d 100644 --- a/block/Kconfig.iosched +++ b/block/Kconfig.iosched @@ -3,7 +3,7 @@ if BLOCK menu "IO Schedulers" config ELV_FAIR_QUEUING - bool "Elevator Fair Queuing Support" + bool default n ---help--- Traditionally only cfq had notion of multiple queues and it did @@ -46,6 +46,7 @@ config IOSCHED_DEADLINE config IOSCHED_CFQ tristate "CFQ I/O scheduler" + select ELV_FAIR_QUEUING default y ---help--- The CFQ I/O scheduler tries to distribute bandwidth equally diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index a55a9bd..995c8dd 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -12,7 +12,6 @@ #include #include #include - /* * tunables */ @@ -23,15 +22,7 @@ static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; 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; - -/* - * offset from end of service tree - */ -#define CFQ_IDLE_DELAY (HZ / 5) /* * below this threshold, we consider thinktime immediate @@ -43,7 +34,7 @@ static int cfq_slice_idle = HZ / 125; #define RQ_CIC(rq) \ ((struct cfq_io_context *) (rq)->elevator_private) -#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) +#define RQ_CFQQ(rq) (struct cfq_queue *) (ioq_sched_queue((rq)->ioq)) static struct kmem_cache *cfq_pool; static struct kmem_cache *cfq_ioc_pool; @@ -53,8 +44,6 @@ 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) -#define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) #define sample_valid(samples) ((samples) > 80) @@ -75,12 +64,6 @@ struct cfq_rb_root { */ struct cfq_data { struct request_queue *queue; - - /* - * rr list of queues with requests and the count of them - */ - struct cfq_rb_root service_tree; - /* * Each priority tree is sorted by next_request position. These * trees are used when determining if two or more queues are @@ -88,41 +71,11 @@ struct cfq_data { */ struct rb_root prio_trees[CFQ_PRIO_LISTS]; - unsigned int busy_queues; - /* - * Used to track any pending rt requests so we can pre-empt current - * non-RT cfqq in service when this value is non-zero. - */ - unsigned int busy_rt_queues; - - 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 - */ - struct timer_list idle_slice_timer; - struct work_struct unplug_work; - - struct cfq_queue *active_queue; struct cfq_io_context *active_cic; - /* - * 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; /* * tunables, see top of file @@ -131,9 +84,7 @@ struct cfq_data { unsigned int cfq_fifo_expire[2]; unsigned int cfq_back_penalty; unsigned int cfq_back_max; - unsigned int cfq_slice[2]; unsigned int cfq_slice_async_rq; - unsigned int cfq_slice_idle; struct list_head cic_list; }; @@ -142,16 +93,11 @@ struct cfq_data { * Per process-grouping structure */ struct cfq_queue { - /* reference count */ - atomic_t ref; + struct io_queue *ioq; /* various state flags, see below */ unsigned int flags; /* parent cfq_data */ struct cfq_data *cfqd; - /* service_tree member */ - struct rb_node rb_node; - /* service_tree key */ - unsigned long rb_key; /* prio tree member */ struct rb_node p_node; /* prio tree root we belong to, if any */ @@ -167,33 +113,23 @@ struct cfq_queue { /* fifo list of requests in sort_list */ struct list_head fifo; - unsigned long slice_end; - long slice_resid; unsigned int slice_dispatch; /* pending metadata requests */ int meta_pending; - /* number of requests that are on the dispatch list or inside driver */ - int dispatched; /* io prio of this group */ - unsigned short ioprio, org_ioprio; - unsigned short ioprio_class, org_ioprio_class; + unsigned short org_ioprio; + unsigned short org_ioprio_class; pid_t pid; }; enum cfqq_state_flags { - CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ - CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ - CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ CFQ_CFQQ_FLAG_must_alloc, /* must be allowed rq alloc */ CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ - CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ - 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 */ }; @@ -211,16 +147,10 @@ static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ } -CFQ_CFQQ_FNS(on_rr); -CFQ_CFQQ_FNS(wait_request); -CFQ_CFQQ_FNS(must_dispatch); CFQ_CFQQ_FNS(must_alloc); CFQ_CFQQ_FNS(must_alloc_slice); CFQ_CFQQ_FNS(fifo_expire); -CFQ_CFQQ_FNS(idle_window); CFQ_CFQQ_FNS(prio_changed); -CFQ_CFQQ_FNS(slice_new); -CFQ_CFQQ_FNS(sync); CFQ_CFQQ_FNS(coop); #undef CFQ_CFQQ_FNS @@ -259,66 +189,27 @@ static inline int cfq_bio_sync(struct bio *bio) return 0; } -/* - * 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) +static inline struct io_group *cfqq_to_io_group(struct cfq_queue *cfqq) { - if (cfqd->busy_queues) { - cfq_log(cfqd, "schedule dispatch"); - kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); - } + return ioq_to_io_group(cfqq->ioq); } -static int cfq_queue_empty(struct request_queue *q) +static inline int cfq_class_idle(struct cfq_queue *cfqq) { - struct cfq_data *cfqd = q->elevator->elevator_data; - - return !cfqd->busy_queues; + return elv_ioq_class_idle(cfqq->ioq); } -/* - * Scale schedule slice based on io priority. Use the sync time slice only - * 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, - unsigned short prio) -{ - const int base_slice = cfqd->cfq_slice[sync]; - - WARN_ON(prio >= IOPRIO_BE_NR); - - return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); -} - -static inline int -cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) -{ - return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); -} - -static inline void -cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) +static inline int cfq_cfqq_sync(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); + return elv_ioq_sync(cfqq->ioq); } -/* - * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end - * 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 int cfqq_is_active_queue(struct cfq_queue *cfqq) { - if (cfq_cfqq_slice_new(cfqq)) - return 0; - if (time_before(jiffies, cfqq->slice_end)) - return 0; + struct cfq_data *cfqd = cfqq->cfqd; + struct elevator_queue *e = cfqd->queue->elevator; - return 1; + return (elv_active_sched_queue(e) == cfqq); } /* @@ -417,33 +308,6 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2) } /* - * The below is leftmost cache rbtree addon - */ -static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) -{ - if (!root->left) - root->left = rb_first(&root->rb); - - if (root->left) - return rb_entry(root->left, struct cfq_queue, rb_node); - - return NULL; -} - -static void rb_erase_init(struct rb_node *n, struct rb_root *root) -{ - rb_erase(n, root); - RB_CLEAR_NODE(n); -} - -static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) -{ - if (root->left == n) - root->left = NULL; - rb_erase_init(n, &root->rb); -} - -/* * would be nice to take fifo expire time into account as well */ static struct request * @@ -456,10 +320,10 @@ cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, BUG_ON(RB_EMPTY_NODE(&last->rb_node)); - if (rbprev) + if (rbprev != NULL) prev = rb_entry_rq(rbprev); - if (rbnext) + if (rbnext != NULL) next = rb_entry_rq(rbnext); else { rbnext = rb_first(&cfqq->sort_list); @@ -470,95 +334,6 @@ cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, return cfq_choose_req(cfqd, next, prev); } -static unsigned long cfq_slice_offset(struct cfq_data *cfqd, - struct cfq_queue *cfqq) -{ - /* - * just an approximation, should be ok. - */ - return (cfqd->busy_queues - 1) * (cfq_prio_slice(cfqd, 1, 0) - - cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); -} - -/* - * The cfqd->service_tree holds all pending cfq_queue's that have - * requests waiting to be processed. It is sorted in the order that - * we will service the queues. - */ -static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, - int add_front) -{ - struct rb_node **p, *parent; - struct cfq_queue *__cfqq; - unsigned long rb_key; - int left; - - 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; - } else - rb_key = 0; - - if (!RB_EMPTY_NODE(&cfqq->rb_node)) { - /* - * same position, nothing more to do - */ - if (rb_key == cfqq->rb_key) - return; - - cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); - } - - left = 1; - parent = NULL; - p = &cfqd->service_tree.rb.rb_node; - while (*p) { - struct rb_node **n; - - parent = *p; - __cfqq = rb_entry(parent, struct cfq_queue, rb_node); - - /* - * sort RT queues first, we always want to give - * preference to them. IDLE queues goes to the back. - * after that, sort on the next service time. - */ - if (cfq_class_rt(cfqq) > cfq_class_rt(__cfqq)) - n = &(*p)->rb_left; - else if (cfq_class_rt(cfqq) < cfq_class_rt(__cfqq)) - n = &(*p)->rb_right; - else if (cfq_class_idle(cfqq) < cfq_class_idle(__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) - n = &(*p)->rb_left; - else - n = &(*p)->rb_right; - - if (n == &(*p)->rb_right) - left = 0; - - p = n; - } - - if (left) - cfqd->service_tree.left = &cfqq->rb_node; - - cfqq->rb_key = rb_key; - rb_link_node(&cfqq->rb_node, parent, p); - rb_insert_color(&cfqq->rb_node, &cfqd->service_tree.rb); -} - static struct cfq_queue * cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, sector_t sector, struct rb_node **ret_parent, @@ -620,57 +395,34 @@ static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) cfqq->p_root = NULL; } -/* - * Update cfqq's position in the service tree. - */ -static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) +/* An active ioq is being reset. A chance to do cic related stuff. */ +static void cfq_active_ioq_reset(struct request_queue *q, void *sched_queue) { - /* - * Resorting requires the cfqq to be on the RR list already. - */ - if (cfq_cfqq_on_rr(cfqq)) { - cfq_service_tree_add(cfqd, cfqq, 0); - cfq_prio_tree_add(cfqd, cfqq); - } -} + struct cfq_data *cfqd = q->elevator->elevator_data; + struct cfq_queue *cfqq = sched_queue; -/* - * add to busy list of queues for service, trying to be fair in ordering - * the pending list according to last request service - */ -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++; - if (cfq_class_rt(cfqq)) - cfqd->busy_rt_queues++; + if (cfqd->active_cic) { + put_io_context(cfqd->active_cic->ioc); + cfqd->active_cic = NULL; + } - cfq_resort_rr_list(cfqd, cfqq); + /* Resort the cfqq in prio tree */ + if (cfqq) + cfq_prio_tree_add(cfqd, cfqq); } -/* - * Called when the cfqq no longer has requests pending, remove it from - * the service tree. - */ -static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) +/* An ioq has been set as active one. */ +static void cfq_active_ioq_set(struct request_queue *q, void *sched_queue, + int coop) { - cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); - BUG_ON(!cfq_cfqq_on_rr(cfqq)); - cfq_clear_cfqq_on_rr(cfqq); + struct cfq_queue *cfqq = sched_queue; - if (!RB_EMPTY_NODE(&cfqq->rb_node)) - cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); - if (cfqq->p_root) { - rb_erase(&cfqq->p_node, cfqq->p_root); - cfqq->p_root = NULL; - } + cfqq->slice_dispatch = 0; - BUG_ON(!cfqd->busy_queues); - cfqd->busy_queues--; - if (cfq_class_rt(cfqq)) - cfqd->busy_rt_queues--; + cfq_clear_cfqq_must_alloc_slice(cfqq); + cfq_clear_cfqq_fifo_expire(cfqq); + if (!coop) + cfq_clear_cfqq_coop(cfqq); } /* @@ -679,7 +431,6 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) static void cfq_del_rq_rb(struct request *rq) { struct cfq_queue *cfqq = RQ_CFQQ(rq); - struct cfq_data *cfqd = cfqq->cfqd; const int sync = rq_is_sync(rq); BUG_ON(!cfqq->queued[sync]); @@ -687,8 +438,17 @@ static void cfq_del_rq_rb(struct request *rq) 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); + /* + * If this was last request in the queue, remove this queue from + * prio trees. For last request nr_queued count will still be 1 as + * elevator fair queuing layer is yet to do the accounting. + */ + if (elv_ioq_nr_queued(cfqq->ioq) == 1) { + if (cfqq->p_root) { + rb_erase(&cfqq->p_node, cfqq->p_root); + cfqq->p_root = NULL; + } + } } static void cfq_add_rq_rb(struct request *rq) @@ -706,9 +466,6 @@ static void cfq_add_rq_rb(struct request *rq) while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) cfq_dispatch_insert(cfqd->queue, __alias); - if (!cfq_cfqq_on_rr(cfqq)) - cfq_add_cfqq_rr(cfqd, cfqq); - /* * check if this request is a better next-serve candidate */ @@ -756,23 +513,9 @@ static void cfq_activate_request(struct request_queue *q, struct request *rq) { struct cfq_data *cfqd = q->elevator->elevator_data; - cfqd->rq_in_driver++; - 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(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) { struct cfq_queue *cfqq = RQ_CFQQ(rq); @@ -783,7 +526,6 @@ 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--; @@ -857,93 +599,21 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq, return 0; } -static void __cfq_set_active_queue(struct cfq_data *cfqd, - struct cfq_queue *cfqq) -{ - if (cfqq) { - cfq_log_cfqq(cfqd, cfqq, "set_active"); - cfqq->slice_end = 0; - cfqq->slice_dispatch = 0; - - cfq_clear_cfqq_wait_request(cfqq); - cfq_clear_cfqq_must_dispatch(cfqq); - cfq_clear_cfqq_must_alloc_slice(cfqq); - cfq_clear_cfqq_fifo_expire(cfqq); - cfq_mark_cfqq_slice_new(cfqq); - - del_timer(&cfqd->idle_slice_timer); - } - - cfqd->active_queue = cfqq; -} - /* * current cfqq expired its slice (or was too idle), select new one */ static void -__cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, - int timed_out) +__cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq) { - cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); - - if (cfq_cfqq_wait_request(cfqq)) - del_timer(&cfqd->idle_slice_timer); - - cfq_clear_cfqq_wait_request(cfqq); - - /* - * store what was left of this slice, if the queue idled/timed out - */ - 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); - - if (cfqq == cfqd->active_queue) - cfqd->active_queue = NULL; - - if (cfqd->active_cic) { - put_io_context(cfqd->active_cic->ioc); - cfqd->active_cic = NULL; - } + __elv_ioq_slice_expired(cfqd->queue, cfqq->ioq); } -static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out) +static inline void cfq_slice_expired(struct cfq_data *cfqd) { - struct cfq_queue *cfqq = cfqd->active_queue; + struct cfq_queue *cfqq = elv_active_sched_queue(cfqd->queue->elevator); if (cfqq) - __cfq_slice_expired(cfqd, cfqq, timed_out); -} - -/* - * 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) -{ - if (RB_EMPTY_ROOT(&cfqd->service_tree.rb)) - return NULL; - - return cfq_rb_first(&cfqd->service_tree); -} - -/* - * Get and set a new active queue for service. - */ -static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, - struct cfq_queue *cfqq) -{ - if (!cfqq) { - cfqq = cfq_get_next_queue(cfqd); - if (cfqq) - cfq_clear_cfqq_coop(cfqq); - } - - __cfq_set_active_queue(cfqd, cfqq); - return cfqq; + __cfq_slice_expired(cfqd, cfqq); } static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, @@ -1020,11 +690,12 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid * assumption. */ -static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, - struct cfq_queue *cur_cfqq, +static struct io_queue *cfq_close_cooperator(struct request_queue *q, + void *cur_sched_queue, int probe) { - struct cfq_queue *cfqq; + struct cfq_queue *cur_cfqq = cur_sched_queue, *cfqq; + struct cfq_data *cfqd = q->elevator->elevator_data; /* * A valid cfq_io_context is necessary to compare requests against @@ -1047,38 +718,18 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, if (!probe) cfq_mark_cfqq_coop(cfqq); - return cfqq; + return cfqq->ioq; } -static void cfq_arm_slice_timer(struct cfq_data *cfqd) +static void cfq_arm_slice_timer(struct request_queue *q, void *sched_queue) { - struct cfq_queue *cfqq = cfqd->active_queue; + struct cfq_data *cfqd = q->elevator->elevator_data; + struct cfq_queue *cfqq = sched_queue; 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)); - - /* - * idle is disabled, either manually or by past process history - */ - if (!cfqd->cfq_slice_idle || !cfq_cfqq_idle_window(cfqq)) - return; - - /* - * still requests with the driver, don't idle - */ - if (cfqd->rq_in_driver) - return; - + WARN_ON(elv_ioq_slice_new(cfqq->ioq)); /* * task has exited, don't wait */ @@ -1086,18 +737,18 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) if (!cic || !atomic_read(&cic->ioc->nr_tasks)) return; - cfq_mark_cfqq_wait_request(cfqq); + elv_mark_ioq_wait_request(cfqq->ioq); /* * we don't want to idle for seeks, but we do want to allow * fair distribution of slice time for a process doing back-to-back * seeks. so allow a little bit of time for him to submit a new rq */ - sl = cfqd->cfq_slice_idle; + sl = elv_get_slice_idle(q->elevator); if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT)); - mod_timer(&cfqd->idle_slice_timer, jiffies + sl); + elv_mod_idle_slice_timer(q->elevator, jiffies + sl); cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl); } @@ -1106,13 +757,12 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) */ 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); + struct cfq_data *cfqd = q->elevator->elevator_data; - cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); + cfq_log_cfqq(cfqd, cfqq, "dispatch_insert sect=%d", rq->nr_sectors); cfq_remove_request(rq); - cfqq->dispatched++; elv_dispatch_sort(q, rq); if (cfq_cfqq_sync(cfqq)) @@ -1150,78 +800,11 @@ static inline int cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) { const int base_rq = cfqd->cfq_slice_async_rq; + unsigned short ioprio = elv_ioq_ioprio(cfqq->ioq); - WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); + WARN_ON(ioprio >= IOPRIO_BE_NR); - return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); -} - -/* - * Select a queue for service. If we have a current active queue, - * check whether to continue servicing it, or retrieve and set a new one. - */ -static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) -{ - struct cfq_queue *cfqq, *new_cfqq = NULL; - - cfqq = cfqd->active_queue; - if (!cfqq) - goto new_queue; - - /* - * The active queue has run out of time, expire it and select new. - */ - if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) - goto expire; - - /* - * If we have a RT cfqq waiting, then we pre-empt the current non-rt - * cfqq. - */ - if (!cfq_class_rt(cfqq) && cfqd->busy_rt_queues) { - /* - * We simulate this as cfqq timed out so that it gets to bank - * the remaining of its time slice. - */ - cfq_log_cfqq(cfqd, cfqq, "preempt"); - cfq_slice_expired(cfqd, 1); - goto new_queue; - } - - /* - * The active queue has requests and isn't expired, allow it to - * dispatch. - */ - if (!RB_EMPTY_ROOT(&cfqq->sort_list)) - goto keep_queue; - - /* - * If another queue has a request waiting within our mean seek - * distance, let it run. The expire code will check for close - * cooperators and put the close queue at the front of the service - * tree. - */ - new_cfqq = cfq_close_cooperator(cfqd, cfqq, 0); - if (new_cfqq) - goto expire; - - /* - * No requests pending. If the active queue still has requests in - * flight or is idling for a new request, allow either of these - * conditions to happen (or time out) before selecting a new queue. - */ - if (timer_pending(&cfqd->idle_slice_timer) || - (cfqq->dispatched && cfq_cfqq_idle_window(cfqq))) { - cfqq = NULL; - goto keep_queue; - } - -expire: - cfq_slice_expired(cfqd, 0); -new_queue: - cfqq = cfq_set_active_queue(cfqd, new_cfqq); -keep_queue: - return cfqq; + return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - ioprio)); } static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) @@ -1246,12 +829,14 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) struct cfq_queue *cfqq; int dispatched = 0; - while ((cfqq = cfq_rb_first(&cfqd->service_tree)) != NULL) + while ((cfqq = elv_select_sched_queue(cfqd->queue, 1)) != NULL) dispatched += __cfq_forced_dispatch_cfqq(cfqq); - cfq_slice_expired(cfqd, 0); + /* This probably is redundant now. above loop will should make sure + * that all the busy queues have expired */ + cfq_slice_expired(cfqd); - BUG_ON(cfqd->busy_queues); + BUG_ON(elv_nr_busy_ioq(cfqd->queue->elevator)); cfq_log(cfqd, "forced_dispatch=%d\n", dispatched); return dispatched; @@ -1297,13 +882,10 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) 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); + cfqq = elv_select_sched_queue(q, 0); if (!cfqq) return 0; @@ -1320,7 +902,7 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) /* * Does this cfqq already have too much IO in flight? */ - if (cfqq->dispatched >= max_dispatch) { + if (elv_ioq_nr_dispatched(cfqq->ioq) >= max_dispatch) { /* * idle queue must always only have a single IO in flight */ @@ -1330,13 +912,13 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) /* * We have other queues, don't allow more IO from this one */ - if (cfqd->busy_queues > 1) + if (elv_nr_busy_ioq(q->elevator) > 1) return 0; /* * we are the only queue, allow up to 4 times of 'quantum' */ - if (cfqq->dispatched >= 4 * max_dispatch) + if (elv_ioq_nr_dispatched(cfqq->ioq) >= 4 * max_dispatch) return 0; } @@ -1345,51 +927,45 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) */ cfq_dispatch_request(cfqd, cfqq); cfqq->slice_dispatch++; - cfq_clear_cfqq_must_dispatch(cfqq); /* * expire an async queue immediately if it has used up its slice. idle * queue always expire after 1 dispatch round. */ - if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && + if (elv_nr_busy_ioq(q->elevator) > 1 && ((!cfq_cfqq_sync(cfqq) && cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || cfq_class_idle(cfqq))) { - cfqq->slice_end = jiffies + 1; - cfq_slice_expired(cfqd, 0); + cfq_slice_expired(cfqd); } cfq_log(cfqd, "dispatched a request"); return 1; } -/* - * 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. - */ -static void cfq_put_queue(struct cfq_queue *cfqq) +static void cfq_free_cfq_queue(struct elevator_queue *e, void *sched_queue) { + struct cfq_queue *cfqq = sched_queue; struct cfq_data *cfqd = cfqq->cfqd; - BUG_ON(atomic_read(&cfqq->ref) <= 0); - - if (!atomic_dec_and_test(&cfqq->ref)) - return; + BUG_ON(!cfqq); - cfq_log_cfqq(cfqd, cfqq, "put_queue"); + cfq_log_cfqq(cfqd, cfqq, "free_queue"); BUG_ON(rb_first(&cfqq->sort_list)); BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); - BUG_ON(cfq_cfqq_on_rr(cfqq)); - if (unlikely(cfqd->active_queue == cfqq)) { - __cfq_slice_expired(cfqd, cfqq, 0); - cfq_schedule_dispatch(cfqd); + if (unlikely(cfqq_is_active_queue(cfqq))) { + __cfq_slice_expired(cfqd, cfqq); + elv_schedule_dispatch(cfqd->queue); } kmem_cache_free(cfq_pool, cfqq); } +static inline void cfq_put_queue(struct cfq_queue *cfqq) +{ + elv_put_ioq(cfqq->ioq); +} + /* * Must always be called with the rcu_read_lock() held */ @@ -1477,9 +1053,9 @@ static void cfq_free_io_context(struct io_context *ioc) 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); + if (unlikely(cfqq == elv_active_sched_queue(cfqd->queue->elevator))) { + __cfq_slice_expired(cfqd, cfqq); + elv_schedule_dispatch(cfqd->queue); } cfq_put_queue(cfqq); @@ -1549,11 +1125,11 @@ static struct cfq_io_context * cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) { struct cfq_io_context *cic; + struct request_queue *q = cfqd->queue; cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, - cfqd->queue->node); + q->node); 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; @@ -1567,7 +1143,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) { struct task_struct *tsk = current; - int ioprio_class; + int ioprio_class, ioprio; if (!cfq_cfqq_prio_changed(cfqq)) return; @@ -1580,30 +1156,33 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) /* * no prio set, inherit CPU scheduling settings */ - cfqq->ioprio = task_nice_ioprio(tsk); - cfqq->ioprio_class = task_nice_ioclass(tsk); + ioprio = task_nice_ioprio(tsk); + ioprio_class = task_nice_ioclass(tsk); break; case IOPRIO_CLASS_RT: - cfqq->ioprio = task_ioprio(ioc); - cfqq->ioprio_class = IOPRIO_CLASS_RT; + ioprio = task_ioprio(ioc); + ioprio_class = IOPRIO_CLASS_RT; break; case IOPRIO_CLASS_BE: - cfqq->ioprio = task_ioprio(ioc); - cfqq->ioprio_class = IOPRIO_CLASS_BE; + ioprio = task_ioprio(ioc); + 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); + ioprio_class = IOPRIO_CLASS_IDLE; + ioprio = 7; + elv_clear_ioq_idle_window(cfqq->ioq); break; } + elv_ioq_set_ioprio_class(cfqq->ioq, ioprio_class); + elv_ioq_set_ioprio(cfqq->ioq, ioprio); + /* * keep track of original prio settings in case we have to temporarily * elevate the priority of this queue */ - cfqq->org_ioprio = cfqq->ioprio; - cfqq->org_ioprio_class = cfqq->ioprio_class; + cfqq->org_ioprio = ioprio; + cfqq->org_ioprio_class = ioprio_class; cfq_clear_cfqq_prio_changed(cfqq); } @@ -1612,11 +1191,12 @@ static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic) struct cfq_data *cfqd = cic->key; struct cfq_queue *cfqq; unsigned long flags; + struct request_queue *q = cfqd->queue; if (unlikely(!cfqd)) return; - spin_lock_irqsave(cfqd->queue->queue_lock, flags); + spin_lock_irqsave(q->queue_lock, flags); cfqq = cic->cfqq[BLK_RW_ASYNC]; if (cfqq) { @@ -1633,7 +1213,7 @@ static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic) if (cfqq) cfq_mark_cfqq_prio_changed(cfqq); - spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); + spin_unlock_irqrestore(q->queue_lock, flags); } static void cfq_ioc_set_ioprio(struct io_context *ioc) @@ -1644,11 +1224,12 @@ static void cfq_ioc_set_ioprio(struct io_context *ioc) static struct cfq_queue * cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync, - struct io_context *ioc, gfp_t gfp_mask) + struct io_context *ioc, gfp_t gfp_mask) { struct cfq_queue *cfqq, *new_cfqq = NULL; struct cfq_io_context *cic; - + struct request_queue *q = cfqd->queue; + struct io_queue *ioq = NULL, *new_ioq = NULL; retry: cic = cfq_cic_lookup(cfqd, ioc); /* cic always exists here */ @@ -1656,8 +1237,7 @@ retry: if (!cfqq) { if (new_cfqq) { - cfqq = new_cfqq; - new_cfqq = NULL; + goto alloc_ioq; } else if (gfp_mask & __GFP_WAIT) { /* * Inform the allocator of the fact that we will @@ -1678,22 +1258,52 @@ retry: if (!cfqq) goto out; } +alloc_ioq: + if (new_ioq) { + ioq = new_ioq; + new_ioq = NULL; + cfqq = new_cfqq; + new_cfqq = NULL; + } else if (gfp_mask & __GFP_WAIT) { + /* + * Inform the allocator of the fact that we will + * just repeat this allocation if it fails, to allow + * the allocator to do whatever it needs to attempt to + * free memory. + */ + spin_unlock_irq(q->queue_lock); + new_ioq = elv_alloc_ioq(q, + gfp_mask | __GFP_NOFAIL | __GFP_ZERO); + spin_lock_irq(q->queue_lock); + goto retry; + } else { + ioq = elv_alloc_ioq(q, gfp_mask | __GFP_ZERO); + if (!ioq) { + kmem_cache_free(cfq_pool, cfqq); + cfqq = NULL; + goto out; + } + } - RB_CLEAR_NODE(&cfqq->rb_node); + /* + * Both cfqq and ioq objects allocated. Do the initializations + * now. + */ RB_CLEAR_NODE(&cfqq->p_node); INIT_LIST_HEAD(&cfqq->fifo); - - atomic_set(&cfqq->ref, 0); cfqq->cfqd = cfqd; cfq_mark_cfqq_prio_changed(cfqq); + cfqq->ioq = ioq; cfq_init_prio_data(cfqq, ioc); + elv_init_ioq(q->elevator, ioq, cfqq, cfqq->org_ioprio_class, + cfqq->org_ioprio, is_sync); if (is_sync) { if (!cfq_class_idle(cfqq)) - cfq_mark_cfqq_idle_window(cfqq); - cfq_mark_cfqq_sync(cfqq); + elv_mark_ioq_idle_window(cfqq->ioq); + elv_mark_ioq_sync(cfqq->ioq); } cfqq->pid = current->pid; cfq_log_cfqq(cfqd, cfqq, "alloced"); @@ -1702,38 +1312,28 @@ retry: if (new_cfqq) kmem_cache_free(cfq_pool, new_cfqq); + if (new_ioq) + elv_free_ioq(new_ioq); + 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) + 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 *async_cfqq = NULL; struct cfq_queue *cfqq = NULL; + struct io_group *iog = io_lookup_io_group_current(cfqd->queue); if (!is_sync) { - async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); - cfqq = *async_cfqq; + async_cfqq = io_group_async_queue_prio(iog, ioprio_class, + ioprio); + cfqq = async_cfqq; } if (!cfqq) { @@ -1742,15 +1342,11 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct io_context *ioc, 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; - } + if (!is_sync && !async_cfqq) + io_group_set_async_queue(iog, ioprio_class, ioprio, cfqq->ioq); - atomic_inc(&cfqq->ref); + /* ioc reference */ + elv_get_ioq(cfqq->ioq); return cfqq; } @@ -1829,6 +1425,7 @@ static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, { unsigned long flags; int ret; + struct request_queue *q = cfqd->queue; ret = radix_tree_preload(gfp_mask); if (!ret) { @@ -1845,9 +1442,9 @@ static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, radix_tree_preload_end(); if (!ret) { - spin_lock_irqsave(cfqd->queue->queue_lock, flags); + spin_lock_irqsave(q->queue_lock, flags); list_add(&cic->queue_list, &cfqd->cic_list); - spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); + spin_unlock_irqrestore(q->queue_lock, flags); } } @@ -1867,10 +1464,11 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) { struct io_context *ioc = NULL; struct cfq_io_context *cic; + struct request_queue *q = cfqd->queue; might_sleep_if(gfp_mask & __GFP_WAIT); - ioc = get_io_context(gfp_mask, cfqd->queue->node); + ioc = get_io_context(gfp_mask, q->node); if (!ioc) return NULL; @@ -1889,7 +1487,6 @@ out: smp_read_barrier_depends(); if (unlikely(ioc->ioprio_changed)) cfq_ioc_set_ioprio(ioc); - return cic; err_free: cfq_cic_free(cic); @@ -1899,17 +1496,6 @@ err: } static void -cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) -{ - unsigned long elapsed = jiffies - cic->last_end_request; - unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); - - cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; - cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; - cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; -} - -static void cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, struct request *rq) { @@ -1940,57 +1526,41 @@ cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, } /* - * Disable idle window if the process thinks too long or seeks so much that - * it doesn't matter + * Disable idle window if the process seeks so much that it doesn't matter */ -static void -cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, - struct cfq_io_context *cic) +static int +cfq_update_idle_window(struct elevator_queue *eq, void *cfqq, + struct request *rq) { - int old_idle, enable_idle; + struct cfq_io_context *cic = RQ_CIC(rq); /* - * Don't idle for async or idle io prio class + * Enabling/Disabling idling based on thinktime has been moved + * in common layer. */ - if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) - return; - - enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); - - 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)) { - if (cic->ttime_mean > cfqd->cfq_slice_idle) - enable_idle = 0; - else - enable_idle = 1; - } + if (!atomic_read(&cic->ioc->nr_tasks) || + (elv_hw_tag(eq) && CIC_SEEKY(cic))) + return 0; - 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); - } + return 1; } /* * 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. + * no or if we aren't sure, a 1 will cause a preemption attempt. + * Some of the preemption logic has been moved to common layer. Only cfq + * specific parts are left here. */ static int -cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, - struct request *rq) +cfq_should_preempt(struct request_queue *q, void *new_cfqq, struct request *rq) { - struct cfq_queue *cfqq; + struct cfq_data *cfqd = q->elevator->elevator_data; + struct cfq_queue *cfqq = elv_active_sched_queue(q->elevator); - cfqq = cfqd->active_queue; if (!cfqq) return 0; - if (cfq_slice_used(cfqq)) + if (elv_ioq_slice_used(cfqq->ioq)) return 1; if (cfq_class_idle(new_cfqq)) @@ -2013,13 +1583,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, if (rq_is_meta(rq) && !cfqq->meta_pending) return 1; - /* - * 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; - - if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) + if (!cfqd->active_cic || !elv_ioq_wait_request(cfqq->ioq)) return 0; /* @@ -2033,29 +1597,10 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, } /* - * cfqq preempts the active queue. if we allowed preempt with no slice left, - * let it have half of its nominal slice. - */ -static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) -{ - cfq_log_cfqq(cfqd, cfqq, "preempt"); - cfq_slice_expired(cfqd, 1); - - /* - * Put the new queue at the front of the of the current list, - * so we know that it will be selected next. - */ - BUG_ON(!cfq_cfqq_on_rr(cfqq)); - - cfq_service_tree_add(cfqd, cfqq, 1); - - cfqq->slice_end = 0; - cfq_mark_cfqq_slice_new(cfqq); -} - -/* * Called when a new fs request (rq) is added (to cfqq). Check if there's * something we should do about it + * After enqueuing the request whether queue should be preempted or kicked + * decision is taken by common layer. */ static void cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, @@ -2063,45 +1608,12 @@ 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++; - cfq_update_io_thinktime(cfqd, cic); cfq_update_io_seektime(cfqd, cic, rq); - cfq_update_idle_window(cfqd, cfqq, cic); cic->last_request_pos = rq->sector + rq->nr_sectors; - - if (cfqq == cfqd->active_queue) { - /* - * Remember that we saw a request from this process, but - * don't start queuing just yet. Otherwise we risk seeing lots - * of tiny requests, because we disrupt the normal plugging - * and merging. If the request is already larger than a single - * page, let it rip immediately. For that case we assume that - * merging is already done. Ditto for a busy system that - * has other work pending, don't risk delaying until the - * idle timer unplug to continue working. - */ - if (cfq_cfqq_wait_request(cfqq)) { - if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || - cfqd->busy_queues > 1) { - del_timer(&cfqd->idle_slice_timer); - blk_start_queueing(cfqd->queue); - } - cfq_mark_cfqq_must_dispatch(cfqq); - } - } 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 - * has some old slice time left and is of higher priority or - * this new queue is RT and the current one is BE - */ - cfq_preempt_queue(cfqd, cfqq); - blk_start_queueing(cfqd->queue); - } } static void cfq_insert_request(struct request_queue *q, struct request *rq) @@ -2119,84 +1631,17 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq) cfq_rq_enqueued(cfqd, cfqq, 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; - const int sync = rq_is_sync(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); - cfqd->rq_in_driver--; - cfqq->dispatched--; - if (cfq_cfqq_sync(cfqq)) cfqd->sync_flight--; - - if (!cfq_class_idle(cfqq)) - cfqd->last_end_request = now; - - if (sync) - RQ_CIC(rq)->last_end_request = now; - - /* - * If this is the active queue, check if it needs to be expired, - * or if we want to idle in case it has no pending requests. - */ - if (cfqd->active_queue == cfqq) { - const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); - - if (cfq_cfqq_slice_new(cfqq)) { - cfq_set_prio_slice(cfqd, cfqq); - cfq_clear_cfqq_slice_new(cfqq); - } - /* - * If there are no requests waiting in this queue, and - * there are other queues ready to issue requests, AND - * those other queues are issuing requests within our - * mean seek distance, give them a chance to run instead - * of idling. - */ - if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) - cfq_slice_expired(cfqd, 1); - else if (cfqq_empty && !cfq_close_cooperator(cfqd, cfqq, 1) && - sync && !rq_noidle(rq)) - cfq_arm_slice_timer(cfqd); - } - - if (!cfqd->rq_in_driver) - cfq_schedule_dispatch(cfqd); } /* @@ -2205,30 +1650,33 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) */ static void cfq_prio_boost(struct cfq_queue *cfqq) { + struct io_queue *ioq = cfqq->ioq; + if (has_fs_excl()) { /* * boost idle prio on transactions that would lock out other * users of the filesystem */ if (cfq_class_idle(cfqq)) - cfqq->ioprio_class = IOPRIO_CLASS_BE; - if (cfqq->ioprio > IOPRIO_NORM) - cfqq->ioprio = IOPRIO_NORM; + elv_ioq_set_ioprio_class(ioq, IOPRIO_CLASS_BE); + if (elv_ioq_ioprio(ioq) > IOPRIO_NORM) + elv_ioq_set_ioprio(ioq, IOPRIO_NORM); + } else { /* * check if we need to unboost the queue */ - if (cfqq->ioprio_class != cfqq->org_ioprio_class) - cfqq->ioprio_class = cfqq->org_ioprio_class; - if (cfqq->ioprio != cfqq->org_ioprio) - cfqq->ioprio = cfqq->org_ioprio; + if (elv_ioq_ioprio_class(ioq) != cfqq->org_ioprio_class) + elv_ioq_set_ioprio_class(ioq, cfqq->org_ioprio_class); + if (elv_ioq_ioprio(ioq) != cfqq->org_ioprio) + elv_ioq_set_ioprio(ioq, cfqq->org_ioprio); } } static inline int __cfq_may_queue(struct cfq_queue *cfqq) { - if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) && - !cfq_cfqq_must_alloc_slice(cfqq)) { + if ((elv_ioq_wait_request(cfqq->ioq) || + cfq_cfqq_must_alloc(cfqq)) && !cfq_cfqq_must_alloc_slice(cfqq)) { cfq_mark_cfqq_must_alloc_slice(cfqq); return ELV_MQUEUE_MUST; } @@ -2280,7 +1728,7 @@ static void cfq_put_request(struct request *rq) put_io_context(RQ_CIC(rq)->ioc); rq->elevator_private = NULL; - rq->elevator_private2 = NULL; + rq->ioq = NULL; cfq_put_queue(cfqq); } @@ -2320,119 +1768,31 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) cfqq->allocated[rw]++; cfq_clear_cfqq_must_alloc(cfqq); - atomic_inc(&cfqq->ref); + elv_get_ioq(cfqq->ioq); spin_unlock_irqrestore(q->queue_lock, flags); rq->elevator_private = cic; - rq->elevator_private2 = cfqq; + rq->ioq = cfqq->ioq; return 0; queue_fail: if (cic) put_io_context(cic->ioc); - cfq_schedule_dispatch(cfqd); + elv_schedule_dispatch(cfqd->queue); spin_unlock_irqrestore(q->queue_lock, flags); cfq_log(cfqd, "set_request fail"); return 1; } -static void cfq_kick_queue(struct work_struct *work) -{ - struct cfq_data *cfqd = - container_of(work, struct cfq_data, unplug_work); - struct request_queue *q = cfqd->queue; - - spin_lock_irq(q->queue_lock); - blk_start_queueing(q); - spin_unlock_irq(q->queue_lock); -} - -/* - * Timer running if the active_queue is currently idling inside its time slice - */ -static void cfq_idle_slice_timer(unsigned long data) -{ - struct cfq_data *cfqd = (struct cfq_data *) data; - struct cfq_queue *cfqq; - unsigned long flags; - int timed_out = 1; - - cfq_log(cfqd, "idle timer fired"); - - spin_lock_irqsave(cfqd->queue->queue_lock, flags); - - cfqq = cfqd->active_queue; - if (cfqq) { - timed_out = 0; - - /* - * We saw a request before the queue expired, let it through - */ - if (cfq_cfqq_must_dispatch(cfqq)) - goto out_kick; - - /* - * expired - */ - if (cfq_slice_used(cfqq)) - goto expire; - - /* - * only expire and reinvoke request handler, if there are - * other queues with pending requests - */ - if (!cfqd->busy_queues) - goto out_cont; - - /* - * not expired and it has a request pending, let it dispatch - */ - if (!RB_EMPTY_ROOT(&cfqq->sort_list)) - goto out_kick; - } -expire: - cfq_slice_expired(cfqd, timed_out); -out_kick: - cfq_schedule_dispatch(cfqd); -out_cont: - 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); - cancel_work_sync(&cfqd->unplug_work); -} - -static void cfq_put_async_queues(struct cfq_data *cfqd) -{ - 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(struct elevator_queue *e) { struct cfq_data *cfqd = e->elevator_data; struct request_queue *q = cfqd->queue; - cfq_shutdown_timer_wq(cfqd); - spin_lock_irq(q->queue_lock); - if (cfqd->active_queue) - __cfq_slice_expired(cfqd, cfqd->active_queue, 0); - while (!list_empty(&cfqd->cic_list)) { struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, struct cfq_io_context, @@ -2441,12 +1801,7 @@ static void cfq_exit_queue(struct elevator_queue *e) __cfq_exit_single_io_context(cfqd, cic); } - cfq_put_async_queues(cfqd); - spin_unlock_irq(q->queue_lock); - - cfq_shutdown_timer_wq(cfqd); - kfree(cfqd); } @@ -2459,8 +1814,6 @@ static void *cfq_init_queue(struct request_queue *q) if (!cfqd) return NULL; - cfqd->service_tree = CFQ_RB_ROOT; - /* * Not strictly needed (since RB_ROOT just clears the node and we * zeroed cfqd on alloc), but better be safe in case someone decides @@ -2473,23 +1826,12 @@ static void *cfq_init_queue(struct request_queue *q) cfqd->queue = q; - init_timer(&cfqd->idle_slice_timer); - cfqd->idle_slice_timer.function = cfq_idle_slice_timer; - cfqd->idle_slice_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]; cfqd->cfq_back_max = cfq_back_max; cfqd->cfq_back_penalty = cfq_back_penalty; - cfqd->cfq_slice[0] = cfq_slice_async; - 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; } @@ -2554,9 +1896,6 @@ SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1); SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); -SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); -SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); -SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); #undef SHOW_FUNCTION @@ -2584,9 +1923,6 @@ STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 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_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); #undef STORE_FUNCTION @@ -2600,10 +1936,10 @@ static struct elv_fs_entry cfq_attrs[] = { CFQ_ATTR(fifo_expire_async), CFQ_ATTR(back_seek_max), CFQ_ATTR(back_seek_penalty), - CFQ_ATTR(slice_sync), - CFQ_ATTR(slice_async), CFQ_ATTR(slice_async_rq), - CFQ_ATTR(slice_idle), + ELV_ATTR(slice_idle), + ELV_ATTR(slice_sync), + ELV_ATTR(slice_async), __ATTR_NULL }; @@ -2616,8 +1952,6 @@ static struct elevator_type iosched_cfq = { .elevator_dispatch_fn = cfq_dispatch_requests, .elevator_add_req_fn = cfq_insert_request, .elevator_activate_req_fn = cfq_activate_request, - .elevator_deactivate_req_fn = cfq_deactivate_request, - .elevator_queue_empty_fn = cfq_queue_empty, .elevator_completed_req_fn = cfq_completed_request, .elevator_former_req_fn = elv_rb_former_request, .elevator_latter_req_fn = elv_rb_latter_request, @@ -2627,7 +1961,15 @@ static struct elevator_type iosched_cfq = { .elevator_init_fn = cfq_init_queue, .elevator_exit_fn = cfq_exit_queue, .trim = cfq_free_io_context, + .elevator_free_sched_queue_fn = cfq_free_cfq_queue, + .elevator_active_ioq_set_fn = cfq_active_ioq_set, + .elevator_active_ioq_reset_fn = cfq_active_ioq_reset, + .elevator_arm_slice_timer_fn = cfq_arm_slice_timer, + .elevator_should_preempt_fn = cfq_should_preempt, + .elevator_update_idle_window_fn = cfq_update_idle_window, + .elevator_close_cooperator_fn = cfq_close_cooperator, }, + .elevator_features = ELV_IOSCHED_NEED_FQ, .elevator_attrs = cfq_attrs, .elevator_name = "cfq", .elevator_owner = THIS_MODULE, @@ -2635,14 +1977,6 @@ static struct elevator_type iosched_cfq = { static int __init cfq_init(void) { - /* - * could be 0 on HZ < 1000 setups - */ - if (!cfq_slice_async) - cfq_slice_async = 1; - if (!cfq_slice_idle) - cfq_slice_idle = 1; - if (cfq_slab_setup()) return -ENOMEM; diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h index 08b987b..5be25b3 100644 --- a/include/linux/iocontext.h +++ b/include/linux/iocontext.h @@ -39,13 +39,8 @@ struct cfq_io_context { struct io_context *ioc; - unsigned long last_end_request; sector_t last_request_pos; - unsigned long ttime_total; - unsigned long ttime_samples; - unsigned long ttime_mean; - unsigned int seek_samples; u64 seek_total; sector_t seek_mean; -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/