From 9a7f38c42c2b92391d9dabaf9f51df7cfe5608e4 Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Wed, 8 Jun 2016 08:55:34 -0600 Subject: [PATCH] cfq-iosched: Convert from jiffies to nanoseconds Convert all time-keeping in CFQ IO scheduler from jiffies to nanoseconds so that we can later make the intervals more fine-grained than jiffies. One jiffie is several miliseconds and even for today's rotating disks that is a noticeable amount of time and thus we leave disk unnecessarily idle. Signed-off-by: Jeff Moyer Signed-off-by: Jan Kara Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 273 ++++++++++++++++++++++---------------------- 1 file changed, 136 insertions(+), 137 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index b1154861f4c9..9c2e82c1ea88 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -10,7 +10,7 @@ #include #include #include -#include +#include #include #include #include @@ -22,28 +22,28 @@ */ /* max queue in one round of service */ static const int cfq_quantum = 8; -static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; +static const u64 cfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 8 }; /* 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 u64 cfq_slice_sync = NSEC_PER_SEC / 10; +static u64 cfq_slice_async = NSEC_PER_SEC / 25; static const int cfq_slice_async_rq = 2; -static int cfq_slice_idle = HZ / 125; -static int cfq_group_idle = HZ / 125; -static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ +static u64 cfq_slice_idle = NSEC_PER_SEC / 125; +static u64 cfq_group_idle = NSEC_PER_SEC / 125; +static const u64 cfq_target_latency = (u64)NSEC_PER_SEC * 3/10; /* 300 ms */ static const int cfq_hist_divisor = 4; /* * offset from end of service tree */ -#define CFQ_IDLE_DELAY (HZ / 5) +#define CFQ_IDLE_DELAY (NSEC_PER_SEC / 5) /* * below this threshold, we consider thinktime immediate */ -#define CFQ_MIN_TT (2) +#define CFQ_MIN_TT (2 * NSEC_PER_SEC / HZ) #define CFQ_SLICE_SCALE (5) #define CFQ_HW_QUEUE_MIN (5) @@ -73,11 +73,11 @@ static struct kmem_cache *cfq_pool; #define CFQ_WEIGHT_LEGACY_MAX 1000 struct cfq_ttime { - unsigned long last_end_request; + u64 last_end_request; - unsigned long ttime_total; + u64 ttime_total; + u64 ttime_mean; unsigned long ttime_samples; - unsigned long ttime_mean; }; /* @@ -94,7 +94,7 @@ struct cfq_rb_root { struct cfq_ttime ttime; }; #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ - .ttime = {.last_end_request = jiffies,},} + .ttime = {.last_end_request = ktime_get_ns(),},} /* * Per process-grouping structure @@ -109,7 +109,7 @@ struct cfq_queue { /* service_tree member */ struct rb_node rb_node; /* service_tree key */ - unsigned long rb_key; + u64 rb_key; /* prio tree member */ struct rb_node p_node; /* prio tree root we belong to, if any */ @@ -126,13 +126,13 @@ struct cfq_queue { struct list_head fifo; /* time when queue got scheduled in to dispatch first request. */ - unsigned long dispatch_start; - unsigned int allocated_slice; - unsigned int slice_dispatch; + u64 dispatch_start; + u64 allocated_slice; + u64 slice_dispatch; /* time when first request from queue completed and slice started. */ - unsigned long slice_start; - unsigned long slice_end; - long slice_resid; + u64 slice_start; + u64 slice_end; + u64 slice_resid; /* pending priority requests */ int prio_pending; @@ -290,7 +290,7 @@ struct cfq_group { struct cfq_rb_root service_trees[2][3]; struct cfq_rb_root service_tree_idle; - unsigned long saved_wl_slice; + u64 saved_wl_slice; enum wl_type_t saved_wl_type; enum wl_class_t saved_wl_class; @@ -329,7 +329,7 @@ struct cfq_data { */ enum wl_class_t serving_wl_class; enum wl_type_t serving_wl_type; - unsigned long workload_expires; + u64 workload_expires; struct cfq_group *serving_group; /* @@ -374,22 +374,22 @@ struct cfq_data { * tunables, see top of file */ unsigned int cfq_quantum; - 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; - unsigned int cfq_group_idle; unsigned int cfq_latency; - unsigned int cfq_target_latency; + u64 cfq_fifo_expire[2]; + u64 cfq_slice[2]; + u64 cfq_slice_idle; + u64 cfq_group_idle; + u64 cfq_target_latency; /* * Fallback dummy cfqq for extreme OOM conditions */ struct cfq_queue oom_cfqq; - unsigned long last_delayed_sync; + u64 last_delayed_sync; }; static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); @@ -676,7 +676,7 @@ static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, } static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, - unsigned long time, unsigned long unaccounted_time) + uint64_t time, unsigned long unaccounted_time) { blkg_stat_add(&cfqg->stats.time, time); #ifdef CONFIG_DEBUG_BLK_CGROUP @@ -788,7 +788,7 @@ static inline void cfqg_put(struct cfq_group *cfqg) { } static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, struct cfq_group *curr_cfqg, int op, int op_flags) { } static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, - unsigned long time, unsigned long unaccounted_time) { } + uint64_t time, unsigned long unaccounted_time) { } static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int op, int op_flags) { } static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int op, @@ -815,7 +815,7 @@ static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd, struct cfq_ttime *ttime, bool group_idle) { - unsigned long slice; + u64 slice; if (!sample_valid(ttime->ttime_samples)) return false; if (group_idle) @@ -938,17 +938,18 @@ static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) * 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, bool sync, +static inline u64 cfq_prio_slice(struct cfq_data *cfqd, bool sync, unsigned short prio) { - const int base_slice = cfqd->cfq_slice[sync]; + u64 base_slice = cfqd->cfq_slice[sync]; + u64 slice = div_u64(base_slice, CFQ_SLICE_SCALE); WARN_ON(prio >= IOPRIO_BE_NR); - return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); + return base_slice + (slice * (4 - prio)); } -static inline int +static inline u64 cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); @@ -966,15 +967,14 @@ cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) * * The result is also in fixed point w/ CFQ_SERVICE_SHIFT. */ -static inline u64 cfqg_scale_charge(unsigned long charge, +static inline u64 cfqg_scale_charge(u64 charge, unsigned int vfraction) { u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */ /* charge / vfraction */ c <<= CFQ_SERVICE_SHIFT; - do_div(c, vfraction); - return c; + return div_u64(c, vfraction); } static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) @@ -1027,16 +1027,16 @@ static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, return cfqg->busy_queues_avg[rt]; } -static inline unsigned +static inline u64 cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) { return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT; } -static inline unsigned +static inline u64 cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { - unsigned slice = cfq_prio_to_slice(cfqd, cfqq); + u64 slice = cfq_prio_to_slice(cfqd, cfqq); if (cfqd->cfq_latency) { /* * interested queues (we consider only the ones with the same @@ -1044,20 +1044,22 @@ cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) */ unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, cfq_class_rt(cfqq)); - unsigned sync_slice = cfqd->cfq_slice[1]; - unsigned expect_latency = sync_slice * iq; - unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); + u64 sync_slice = cfqd->cfq_slice[1]; + u64 expect_latency = sync_slice * iq; + u64 group_slice = cfq_group_slice(cfqd, cfqq->cfqg); if (expect_latency > group_slice) { - unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; + u64 base_low_slice = 2 * cfqd->cfq_slice_idle; + u64 low_slice; + /* scale low_slice according to IO priority * and sync vs async */ - unsigned low_slice = - min(slice, base_low_slice * slice / sync_slice); + low_slice = div64_u64(base_low_slice*slice, sync_slice); + low_slice = min(slice, low_slice); /* the adapted slice value is scaled to fit all iqs * into the target latency */ - slice = max(slice * group_slice / expect_latency, - low_slice); + slice = div64_u64(slice*group_slice, expect_latency); + slice = max(slice, low_slice); } } return slice; @@ -1066,12 +1068,13 @@ cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) static inline void cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { - unsigned slice = cfq_scaled_cfqq_slice(cfqd, cfqq); + u64 slice = cfq_scaled_cfqq_slice(cfqd, cfqq); + u64 now = ktime_get_ns(); - cfqq->slice_start = jiffies; - cfqq->slice_end = jiffies + slice; + cfqq->slice_start = now; + cfqq->slice_end = now + slice; cfqq->allocated_slice = slice; - cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); + cfq_log_cfqq(cfqd, cfqq, "set_slice=%llu", cfqq->slice_end - now); } /* @@ -1083,7 +1086,7 @@ static inline bool cfq_slice_used(struct cfq_queue *cfqq) { if (cfq_cfqq_slice_new(cfqq)) return false; - if (time_before(jiffies, cfqq->slice_end)) + if (ktime_get_ns() < cfqq->slice_end) return false; return true; @@ -1249,8 +1252,8 @@ cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); } -static unsigned long cfq_slice_offset(struct cfq_data *cfqd, - struct cfq_queue *cfqq) +static u64 cfq_slice_offset(struct cfq_data *cfqd, + struct cfq_queue *cfqq) { /* * just an approximation, should be ok. @@ -1443,31 +1446,31 @@ cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg) cfqg_stats_update_dequeue(cfqg); } -static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq, - unsigned int *unaccounted_time) +static inline u64 cfq_cfqq_slice_usage(struct cfq_queue *cfqq, + u64 *unaccounted_time) { - unsigned int slice_used; + u64 slice_used; + u64 now = ktime_get_ns(); /* * Queue got expired before even a single request completed or * got expired immediately after first request completion. */ - if (!cfqq->slice_start || cfqq->slice_start == jiffies) { + if (!cfqq->slice_start || cfqq->slice_start == now) { /* * Also charge the seek time incurred to the group, otherwise * if there are mutiple queues in the group, each can dispatch * a single request on seeky media and cause lots of seek time * and group will never know it. */ - slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), - 1); + slice_used = max_t(u64, (now - cfqq->dispatch_start), 1); } else { - slice_used = jiffies - cfqq->slice_start; + slice_used = now - cfqq->slice_start; if (slice_used > cfqq->allocated_slice) { *unaccounted_time = slice_used - cfqq->allocated_slice; slice_used = cfqq->allocated_slice; } - if (time_after(cfqq->slice_start, cfqq->dispatch_start)) + if (cfqq->slice_start > cfqq->dispatch_start) *unaccounted_time += cfqq->slice_start - cfqq->dispatch_start; } @@ -1479,10 +1482,11 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, struct cfq_queue *cfqq) { struct cfq_rb_root *st = &cfqd->grp_service_tree; - unsigned int used_sl, charge, unaccounted_sl = 0; + u64 used_sl, charge, unaccounted_sl = 0; int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) - cfqg->service_tree_idle.count; unsigned int vfr; + u64 now = ktime_get_ns(); BUG_ON(nr_sync < 0); used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl); @@ -1504,9 +1508,8 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, cfq_group_service_tree_add(st, cfqg); /* This group is being expired. Save the context */ - if (time_after(cfqd->workload_expires, jiffies)) { - cfqg->saved_wl_slice = cfqd->workload_expires - - jiffies; + if (cfqd->workload_expires > now) { + cfqg->saved_wl_slice = cfqd->workload_expires - now; cfqg->saved_wl_type = cfqd->serving_wl_type; cfqg->saved_wl_class = cfqd->serving_wl_class; } else @@ -1515,7 +1518,7 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, st->min_vdisktime); cfq_log_cfqq(cfqq->cfqd, cfqq, - "sl_used=%u disp=%u charge=%u iops=%u sect=%lu", + "sl_used=%llu disp=%llu charge=%llu iops=%u sect=%lu", used_sl, cfqq->slice_dispatch, charge, iops_mode(cfqd), cfqq->nr_sectors); cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl); @@ -1538,7 +1541,7 @@ static void cfq_init_cfqg_base(struct cfq_group *cfqg) *st = CFQ_RB_ROOT; RB_CLEAR_NODE(&cfqg->rb_node); - cfqg->ttime.last_end_request = jiffies; + cfqg->ttime.last_end_request = ktime_get_ns(); } #ifdef CONFIG_CFQ_GROUP_IOSCHED @@ -2221,10 +2224,11 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, { struct rb_node **p, *parent; struct cfq_queue *__cfqq; - unsigned long rb_key; + u64 rb_key; struct cfq_rb_root *st; int left; int new_cfqq = 1; + u64 now = ktime_get_ns(); st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); if (cfq_class_idle(cfqq)) { @@ -2234,7 +2238,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, __cfqq = rb_entry(parent, struct cfq_queue, rb_node); rb_key += __cfqq->rb_key; } else - rb_key += jiffies; + rb_key += now; } else if (!add_front) { /* * Get our rb key offset. Subtract any residual slice @@ -2242,13 +2246,13 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, * count indicates slice overrun, and this should position * the next service time further away in the tree. */ - rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; + rb_key = cfq_slice_offset(cfqd, cfqq) + now; rb_key -= cfqq->slice_resid; cfqq->slice_resid = 0; } else { - rb_key = -HZ; + rb_key = -NSEC_PER_SEC; __cfqq = cfq_rb_first(st); - rb_key += __cfqq ? __cfqq->rb_key : jiffies; + rb_key += __cfqq ? __cfqq->rb_key : now; } if (!RB_EMPTY_NODE(&cfqq->rb_node)) { @@ -2274,7 +2278,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, /* * sort by key, that represents service time. */ - if (time_before(rb_key, __cfqq->rb_key)) + if (rb_key < __cfqq->rb_key) p = &parent->rb_left; else { p = &parent->rb_right; @@ -2574,7 +2578,7 @@ cfq_merged_requests(struct request_queue *q, struct request *rq, * reposition in fifo if next is older than rq */ if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && - time_before(next->fifo_time, rq->fifo_time) && + next->fifo_time < rq->fifo_time && cfqq == RQ_CFQQ(next)) { list_move(&rq->queuelist, &next->queuelist); rq->fifo_time = next->fifo_time; @@ -2635,7 +2639,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd, cfqd->serving_wl_class, cfqd->serving_wl_type); cfqg_stats_update_avg_queue_size(cfqq->cfqg); cfqq->slice_start = 0; - cfqq->dispatch_start = jiffies; + cfqq->dispatch_start = ktime_get_ns(); cfqq->allocated_slice = 0; cfqq->slice_end = 0; cfqq->slice_dispatch = 0; @@ -2684,8 +2688,8 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (cfq_cfqq_slice_new(cfqq)) cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq); else - cfqq->slice_resid = cfqq->slice_end - jiffies; - cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); + cfqq->slice_resid = cfqq->slice_end - ktime_get_ns(); + cfq_log_cfqq(cfqd, cfqq, "resid=%llu", cfqq->slice_resid); } cfq_group_served(cfqd, cfqq->cfqg, cfqq); @@ -2919,7 +2923,8 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) struct cfq_queue *cfqq = cfqd->active_queue; struct cfq_rb_root *st = cfqq->service_tree; struct cfq_io_cq *cic; - unsigned long sl, group_idle = 0; + u64 sl, group_idle = 0; + u64 now = ktime_get_ns(); /* * SSD device without seek penalty, disable idling. But only do so @@ -2962,8 +2967,8 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) * time slice. */ if (sample_valid(cic->ttime.ttime_samples) && - (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) { - cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%lu", + (cfqq->slice_end - now < cic->ttime.ttime_mean)) { + cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%llu", cic->ttime.ttime_mean); return; } @@ -2984,9 +2989,9 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) else sl = cfqd->cfq_slice_idle; - mod_timer(&cfqd->idle_slice_timer, jiffies + sl); + mod_timer(&cfqd->idle_slice_timer, now + sl); cfqg_stats_set_start_idle_time(cfqq->cfqg); - cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl, + cfq_log_cfqq(cfqd, cfqq, "arm_idle: %llu group_idle: %d", sl, group_idle ? 1 : 0); } @@ -3026,7 +3031,7 @@ static struct request *cfq_check_fifo(struct cfq_queue *cfqq) return NULL; rq = rq_entry_fifo(cfqq->fifo.next); - if (time_before(jiffies, rq->fifo_time)) + if (ktime_get_ns() < rq->fifo_time) rq = NULL; cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); @@ -3104,14 +3109,14 @@ static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd, struct cfq_queue *queue; int i; bool key_valid = false; - unsigned long lowest_key = 0; + u64 lowest_key = 0; enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; for (i = 0; i <= SYNC_WORKLOAD; ++i) { /* select the one with lowest rb_key */ queue = cfq_rb_first(st_for(cfqg, wl_class, i)); if (queue && - (!key_valid || time_before(queue->rb_key, lowest_key))) { + (!key_valid || queue->rb_key < lowest_key)) { lowest_key = queue->rb_key; cur_best = i; key_valid = true; @@ -3124,11 +3129,12 @@ static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd, static void choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) { - unsigned slice; + u64 slice; unsigned count; struct cfq_rb_root *st; - unsigned group_slice; + u64 group_slice; enum wl_class_t original_class = cfqd->serving_wl_class; + u64 now = ktime_get_ns(); /* Choose next priority. RT > BE > IDLE */ if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) @@ -3137,7 +3143,7 @@ choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) cfqd->serving_wl_class = BE_WORKLOAD; else { cfqd->serving_wl_class = IDLE_WORKLOAD; - cfqd->workload_expires = jiffies + 1; + cfqd->workload_expires = now + jiffies_to_nsecs(1); return; } @@ -3155,7 +3161,7 @@ choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) /* * check workload expiration, and that we still have other queues ready */ - if (count && !time_after(jiffies, cfqd->workload_expires)) + if (count && !(now > cfqd->workload_expires)) return; new_workload: @@ -3172,13 +3178,13 @@ new_workload: */ group_slice = cfq_group_slice(cfqd, cfqg); - slice = group_slice * count / + slice = div_u64(group_slice * count, max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class], cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd, - cfqg)); + cfqg))); if (cfqd->serving_wl_type == ASYNC_WORKLOAD) { - unsigned int tmp; + u64 tmp; /* * Async queues are currently system wide. Just taking @@ -3189,19 +3195,19 @@ new_workload: */ tmp = cfqd->cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg); - tmp = tmp/cfqd->busy_queues; - slice = min_t(unsigned, slice, tmp); + tmp = div_u64(tmp, cfqd->busy_queues); + slice = min_t(u64, slice, tmp); /* async workload slice is scaled down according to * the sync/async slice ratio. */ - slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; + slice = div64_u64(slice*cfqd->cfq_slice[0], cfqd->cfq_slice[1]); } else /* sync workload slice is at least 2 * cfq_slice_idle */ slice = max(slice, 2 * cfqd->cfq_slice_idle); - slice = max_t(unsigned, slice, CFQ_MIN_TT); - cfq_log(cfqd, "workload slice:%d", slice); - cfqd->workload_expires = jiffies + slice; + slice = max_t(u64, slice, CFQ_MIN_TT); + cfq_log(cfqd, "workload slice:%llu", slice); + cfqd->workload_expires = now + slice; } static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) @@ -3219,16 +3225,17 @@ static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) static void cfq_choose_cfqg(struct cfq_data *cfqd) { struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); + u64 now = ktime_get_ns(); cfqd->serving_group = cfqg; /* Restore the workload type data */ if (cfqg->saved_wl_slice) { - cfqd->workload_expires = jiffies + cfqg->saved_wl_slice; + cfqd->workload_expires = now + cfqg->saved_wl_slice; cfqd->serving_wl_type = cfqg->saved_wl_type; cfqd->serving_wl_class = cfqg->saved_wl_class; } else - cfqd->workload_expires = jiffies - 1; + cfqd->workload_expires = now - 1; choose_wl_class_and_type(cfqd, cfqg); } @@ -3240,6 +3247,7 @@ static void cfq_choose_cfqg(struct cfq_data *cfqd) static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) { struct cfq_queue *cfqq, *new_cfqq = NULL; + u64 now = ktime_get_ns(); cfqq = cfqd->active_queue; if (!cfqq) @@ -3311,7 +3319,7 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) **/ if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) && (cfq_cfqq_slice_new(cfqq) || - (cfqq->slice_end - jiffies > jiffies - cfqq->slice_start))) { + (cfqq->slice_end - now > now - cfqq->slice_start))) { cfq_clear_cfqq_deep(cfqq); cfq_clear_cfqq_idle_window(cfqq); } @@ -3389,11 +3397,12 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, struct cfq_queue *cfqq) { + u64 now = ktime_get_ns(); + /* the queue hasn't finished any request, can't estimate */ if (cfq_cfqq_slice_new(cfqq)) return true; - if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, - cfqq->slice_end)) + if (now + cfqd->cfq_slice_idle * cfqq->dispatched > cfqq->slice_end) return true; return false; @@ -3468,10 +3477,10 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) * based on the last sync IO we serviced */ if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { - unsigned long last_sync = jiffies - cfqd->last_delayed_sync; + u64 last_sync = ktime_get_ns() - cfqd->last_delayed_sync; unsigned int depth; - depth = last_sync / cfqd->cfq_slice[1]; + depth = div64_u64(last_sync, cfqd->cfq_slice[1]); if (!depth && !cfqq->dispatched) depth = 1; if (depth < max_dispatch) @@ -3554,7 +3563,7 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || cfq_class_idle(cfqq))) { - cfqq->slice_end = jiffies + 1; + cfqq->slice_end = ktime_get_ns() + 1; cfq_slice_expired(cfqd, 0); } @@ -3632,7 +3641,7 @@ static void cfq_init_icq(struct io_cq *icq) { struct cfq_io_cq *cic = icq_to_cic(icq); - cic->ttime.last_end_request = jiffies; + cic->ttime.last_end_request = ktime_get_ns(); } static void cfq_exit_icq(struct io_cq *icq) @@ -3853,14 +3862,15 @@ out: } static void -__cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle) +__cfq_update_io_thinktime(struct cfq_ttime *ttime, u64 slice_idle) { - unsigned long elapsed = jiffies - ttime->last_end_request; + u64 elapsed = ktime_get_ns() - ttime->last_end_request; elapsed = min(elapsed, 2UL * slice_idle); ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; - ttime->ttime_total = (7*ttime->ttime_total + 256*elapsed) / 8; - ttime->ttime_mean = (ttime->ttime_total + 128) / ttime->ttime_samples; + ttime->ttime_total = div_u64(7*ttime->ttime_total + 256*elapsed, 8); + ttime->ttime_mean = div64_ul(ttime->ttime_total + 128, + ttime->ttime_samples); } static void @@ -4113,7 +4123,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq) cfq_log_cfqq(cfqd, cfqq, "insert_request"); cfq_init_prio_data(cfqq, RQ_CIC(rq)); - rq->fifo_time = jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; + rq->fifo_time = ktime_get_ns() + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; list_add_tail(&rq->queuelist, &cfqq->fifo); cfq_add_rq_rb(rq); cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group, req_op(rq), @@ -4161,6 +4171,7 @@ static void cfq_update_hw_tag(struct cfq_data *cfqd) static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) { struct cfq_io_cq *cic = cfqd->active_cic; + u64 now = ktime_get_ns(); /* If the queue already has requests, don't wait */ if (!RB_EMPTY_ROOT(&cfqq->sort_list)) @@ -4179,7 +4190,7 @@ static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) /* if slice left is less than think time, wait busy */ if (cic && sample_valid(cic->ttime.ttime_samples) - && (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) + && (cfqq->slice_end - now < cic->ttime.ttime_mean)) return true; /* @@ -4189,7 +4200,7 @@ static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) * case where think time is less than a jiffy, mark the queue wait * busy if only 1 jiffy is left in the slice. */ - if (cfqq->slice_end - jiffies == 1) + if (cfqq->slice_end - now <= jiffies_to_nsecs(1)) return true; return false; @@ -4200,9 +4211,8 @@ 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; + u64 now = ktime_get_ns(); - now = jiffies; cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!(rq->cmd_flags & REQ_NOIDLE)); @@ -4231,7 +4241,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) cfqq_type(cfqq)); st->ttime.last_end_request = now; - if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) + if (!(rq->start_time + cfqd->cfq_fifo_expire[1] > now)) cfqd->last_delayed_sync = now; } @@ -4256,10 +4266,10 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) * the queue. */ if (cfq_should_wait_busy(cfqd, cfqq)) { - unsigned long extend_sl = cfqd->cfq_slice_idle; + u64 extend_sl = cfqd->cfq_slice_idle; if (!cfqd->cfq_slice_idle) extend_sl = cfqd->cfq_group_idle; - cfqq->slice_end = jiffies + extend_sl; + cfqq->slice_end = now + extend_sl; cfq_mark_cfqq_wait_busy(cfqq); cfq_log_cfqq(cfqd, cfqq, "will busy wait"); } @@ -4618,7 +4628,7 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) * we optimistically start assuming sync ops weren't delayed in last * second, in order to have larger depth for async operations. */ - cfqd->last_delayed_sync = jiffies - HZ; + cfqd->last_delayed_sync = ktime_get_ns() - NSEC_PER_SEC; return 0; out_free: @@ -4661,9 +4671,9 @@ cfq_var_store(unsigned int *var, const char *page, size_t count) static ssize_t __FUNC(struct elevator_queue *e, char *page) \ { \ struct cfq_data *cfqd = e->elevator_data; \ - unsigned int __data = __VAR; \ + u64 __data = __VAR; \ if (__CONV) \ - __data = jiffies_to_msecs(__data); \ + __data = div_u64(__data, NSEC_PER_MSEC); \ return cfq_var_show(__data, (page)); \ } SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); @@ -4691,7 +4701,7 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) else if (__data > (MAX)) \ __data = (MAX); \ if (__CONV) \ - *(__PTR) = msecs_to_jiffies(__data); \ + *(__PTR) = (u64)__data * NSEC_PER_MSEC; \ else \ *(__PTR) = __data; \ return ret; \ @@ -4785,18 +4795,7 @@ static int __init cfq_init(void) { int ret; - /* - * could be 0 on HZ < 1000 setups - */ - if (!cfq_slice_async) - cfq_slice_async = 1; - if (!cfq_slice_idle) - cfq_slice_idle = 1; - #ifdef CONFIG_CFQ_GROUP_IOSCHED - if (!cfq_group_idle) - cfq_group_idle = 1; - ret = blkcg_policy_register(&blkcg_policy_cfq); if (ret) return ret; -- 2.30.2