diff options
| -rw-r--r-- | Documentation/ABI/stable/sysfs-block | 12 | ||||
| -rw-r--r-- | arch/loongarch/configs/loongson3_defconfig | 1 | ||||
| -rw-r--r-- | block/Kconfig | 11 | ||||
| -rw-r--r-- | block/bio.c | 1 | ||||
| -rw-r--r-- | block/blk-stat.c | 3 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 7 | ||||
| -rw-r--r-- | block/blk-throttle.c | 888 | ||||
| -rw-r--r-- | block/blk-throttle.h | 26 | ||||
| -rw-r--r-- | block/blk.h | 11 |
9 files changed, 42 insertions, 918 deletions
diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index f0025d1c3d5a..831f19a32e08 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -594,18 +594,6 @@ Description: the data. If no such restriction exists, this file will contain '0'. This file is writable for testing purposes. - -What: /sys/block/<disk>/queue/throttle_sample_time -Date: March 2017 -Contact: linux-block@vger.kernel.org -Description: - [RW] This is the time window that blk-throttle samples data, in - millisecond. blk-throttle makes decision based on the - samplings. Lower time means cgroups have more smooth throughput, - but higher CPU overhead. This exists only when - CONFIG_BLK_DEV_THROTTLING_LOW is enabled. - - What: /sys/block/<disk>/queue/virt_boundary_mask Date: April 2021 Contact: linux-block@vger.kernel.org diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index f18c2ba871ef..fc0d89d4c1c5 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -76,7 +76,6 @@ CONFIG_MODULE_FORCE_UNLOAD=y CONFIG_MODVERSIONS=y CONFIG_BLK_DEV_ZONED=y CONFIG_BLK_DEV_THROTTLING=y -CONFIG_BLK_DEV_THROTTLING_LOW=y CONFIG_BLK_WBT=y CONFIG_BLK_CGROUP_IOLATENCY=y CONFIG_BLK_CGROUP_FC_APPID=y diff --git a/block/Kconfig b/block/Kconfig index d47398ae9824..dc12af58dbae 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -119,17 +119,6 @@ config BLK_DEV_THROTTLING See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information. -config BLK_DEV_THROTTLING_LOW - bool "Block throttling .low limit interface support (EXPERIMENTAL)" - depends on BLK_DEV_THROTTLING - help - Add .low limit interface for block throttling. The low limit is a best - effort limit to prioritize cgroups. Depending on the setting, the limit - can be used to protect cgroups in terms of bandwidth/iops and better - utilize disk resource. - - Note, this is an experimental interface and could be changed someday. - config BLK_WBT bool "Enable support for block device writeback throttling" help diff --git a/block/bio.c b/block/bio.c index dce12a0efdea..53f608028c78 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1629,7 +1629,6 @@ again: goto again; } - blk_throtl_bio_endio(bio); /* release cgroup info */ bio_uninit(bio); if (bio->bi_end_io) diff --git a/block/blk-stat.c b/block/blk-stat.c index e42c263e53fb..eaf60097bbe1 100644 --- a/block/blk-stat.c +++ b/block/blk-stat.c @@ -57,9 +57,6 @@ void blk_stat_add(struct request *rq, u64 now) value = (now >= rq->io_start_time_ns) ? now - rq->io_start_time_ns : 0; - if (req_op(rq) == REQ_OP_READ || req_op(rq) == REQ_OP_WRITE) - blk_throtl_stat_add(rq, value); - rcu_read_lock(); cpu = get_cpu(); list_for_each_entry_rcu(cb, &q->stats->callbacks, list) { diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index e3ed5a921aff..8796c350b33d 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -516,10 +516,6 @@ QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask"); QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment"); -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW -QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time"); -#endif - /* legacy alias for logical_block_size: */ static struct queue_sysfs_entry queue_hw_sector_size_entry = { .attr = {.name = "hw_sector_size", .mode = 0444 }, @@ -640,9 +636,6 @@ static struct attribute *queue_attrs[] = { &queue_fua_entry.attr, &queue_dax_entry.attr, &queue_poll_delay_entry.attr, -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW - &blk_throtl_sample_time_entry.attr, -#endif &queue_virt_boundary_mask_entry.attr, &queue_dma_alignment_entry.attr, NULL, diff --git a/block/blk-throttle.c b/block/blk-throttle.c index c515e1a96fad..d907040859f9 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -25,18 +25,6 @@ #define DFL_THROTL_SLICE_HD (HZ / 10) #define DFL_THROTL_SLICE_SSD (HZ / 50) #define MAX_THROTL_SLICE (HZ) -#define MAX_IDLE_TIME (5L * 1000 * 1000) /* 5 s */ -#define MIN_THROTL_BPS (320 * 1024) -#define MIN_THROTL_IOPS (10) -#define DFL_LATENCY_TARGET (-1L) -#define DFL_IDLE_THRESHOLD (0) -#define DFL_HD_BASELINE_LATENCY (4000L) /* 4ms */ -#define LATENCY_FILTERED_SSD (0) -/* - * For HD, very small latency comes from sequential IO. Such IO is helpless to - * help determine if its IO is impacted by others, hence we ignore the IO - */ -#define LATENCY_FILTERED_HD (1000L) /* 1ms */ /* A workqueue to queue throttle related work */ static struct workqueue_struct *kthrotld_workqueue; @@ -70,19 +58,6 @@ struct throtl_data /* Work for dispatching throttled bios */ struct work_struct dispatch_work; - unsigned int limit_index; - bool limit_valid[LIMIT_CNT]; - - unsigned long low_upgrade_time; - unsigned long low_downgrade_time; - - unsigned int scale; - - struct latency_bucket tmp_buckets[2][LATENCY_BUCKET_SIZE]; - struct avg_latency_bucket avg_buckets[2][LATENCY_BUCKET_SIZE]; - struct latency_bucket __percpu *latency_buckets[2]; - unsigned long last_calculate_time; - unsigned long filtered_latency; bool track_bio_latency; }; @@ -126,84 +101,24 @@ static struct throtl_data *sq_to_td(struct throtl_service_queue *sq) return container_of(sq, struct throtl_data, service_queue); } -/* - * cgroup's limit in LIMIT_MAX is scaled if low limit is set. This scale is to - * make the IO dispatch more smooth. - * Scale up: linearly scale up according to elapsed time since upgrade. For - * every throtl_slice, the limit scales up 1/2 .low limit till the - * limit hits .max limit - * Scale down: exponentially scale down if a cgroup doesn't hit its .low limit - */ -static uint64_t throtl_adjusted_limit(uint64_t low, struct throtl_data *td) -{ - /* arbitrary value to avoid too big scale */ - if (td->scale < 4096 && time_after_eq(jiffies, - td->low_upgrade_time + td->scale * td->throtl_slice)) - td->scale = (jiffies - td->low_upgrade_time) / td->throtl_slice; - - return low + (low >> 1) * td->scale; -} - static uint64_t tg_bps_limit(struct throtl_grp *tg, int rw) { struct blkcg_gq *blkg = tg_to_blkg(tg); - struct throtl_data *td; - uint64_t ret; if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent) return U64_MAX; - td = tg->td; - ret = tg->bps[rw][td->limit_index]; - if (ret == 0 && td->limit_index == LIMIT_LOW) { - /* intermediate node or iops isn't 0 */ - if (!list_empty(&blkg->blkcg->css.children) || - tg->iops[rw][td->limit_index]) - return U64_MAX; - else - return MIN_THROTL_BPS; - } - - if (td->limit_index == LIMIT_MAX && tg->bps[rw][LIMIT_LOW] && - tg->bps[rw][LIMIT_LOW] != tg->bps[rw][LIMIT_MAX]) { - uint64_t adjusted; - - adjusted = throtl_adjusted_limit(tg->bps[rw][LIMIT_LOW], td); - ret = min(tg->bps[rw][LIMIT_MAX], adjusted); - } - return ret; + return tg->bps[rw]; } static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw) { struct blkcg_gq *blkg = tg_to_blkg(tg); - struct throtl_data *td; - unsigned int ret; if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent) return UINT_MAX; - td = tg->td; - ret = tg->iops[rw][td->limit_index]; - if (ret == 0 && tg->td->limit_index == LIMIT_LOW) { - /* intermediate node or bps isn't 0 */ - if (!list_empty(&blkg->blkcg->css.children) || - tg->bps[rw][td->limit_index]) - return UINT_MAX; - else - return MIN_THROTL_IOPS; - } - - if (td->limit_index == LIMIT_MAX && tg->iops[rw][LIMIT_LOW] && - tg->iops[rw][LIMIT_LOW] != tg->iops[rw][LIMIT_MAX]) { - uint64_t adjusted; - - adjusted = throtl_adjusted_limit(tg->iops[rw][LIMIT_LOW], td); - if (adjusted > UINT_MAX) - adjusted = UINT_MAX; - ret = min_t(unsigned int, tg->iops[rw][LIMIT_MAX], adjusted); - } - return ret; + return tg->iops[rw]; } #define request_bucket_index(sectors) \ @@ -359,20 +274,10 @@ static struct blkg_policy_data *throtl_pd_alloc(struct gendisk *disk, } RB_CLEAR_NODE(&tg->rb_node); - tg->bps[READ][LIMIT_MAX] = U64_MAX; - tg->bps[WRITE][LIMIT_MAX] = U64_MAX; - tg->iops[READ][LIMIT_MAX] = UINT_MAX; - tg->iops[WRITE][LIMIT_MAX] = UINT_MAX; - tg->bps_conf[READ][LIMIT_MAX] = U64_MAX; - tg->bps_conf[WRITE][LIMIT_MAX] = U64_MAX; - tg->iops_conf[READ][LIMIT_MAX] = UINT_MAX; - tg->iops_conf[WRITE][LIMIT_MAX] = UINT_MAX; - /* LIMIT_LOW will have default value 0 */ - - tg->latency_target = DFL_LATENCY_TARGET; - tg->latency_target_conf = DFL_LATENCY_TARGET; - tg->idletime_threshold = DFL_IDLE_THRESHOLD; - tg->idletime_threshold_conf = DFL_IDLE_THRESHOLD; + tg->bps[READ] = U64_MAX; + tg->bps[WRITE] = U64_MAX; + tg->iops[READ] = UINT_MAX; + tg->iops[WRITE] = UINT_MAX; return &tg->pd; @@ -418,18 +323,15 @@ static void throtl_pd_init(struct blkg_policy_data *pd) static void tg_update_has_rules(struct throtl_grp *tg) { struct throtl_grp *parent_tg = sq_to_tg(tg->service_queue.parent_sq); - struct throtl_data *td = tg->td; int rw; for (rw = READ; rw <= WRITE; rw++) { tg->has_rules_iops[rw] = (parent_tg && parent_tg->has_rules_iops[rw]) || - (td->limit_valid[td->limit_index] && - tg_iops_limit(tg, rw) != UINT_MAX); + tg_iops_limit(tg, rw) != UINT_MAX; tg->has_rules_bps[rw] = (parent_tg && parent_tg->has_rules_bps[rw]) || - (td->limit_valid[td->limit_index] && - (tg_bps_limit(tg, rw) != U64_MAX)); + tg_bps_limit(tg, rw) != U64_MAX; } } @@ -443,49 +345,6 @@ static void throtl_pd_online(struct blkg_policy_data *pd) tg_update_has_rules(tg); } -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW -static void blk_throtl_update_limit_valid(struct throtl_data *td) -{ - struct cgroup_subsys_state *pos_css; - struct blkcg_gq *blkg; - bool low_valid = false; - - rcu_read_lock(); - blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { - struct throtl_grp *tg = blkg_to_tg(blkg); - - if (tg->bps[READ][LIMIT_LOW] || tg->bps[WRITE][LIMIT_LOW] || - tg->iops[READ][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) { - low_valid = true; - break; - } - } - rcu_read_unlock(); - - td->limit_valid[LIMIT_LOW] = low_valid; -} -#else -static inline void blk_throtl_update_limit_valid(struct throtl_data *td) -{ -} -#endif - -static void throtl_upgrade_state(struct throtl_data *td); -static void throtl_pd_offline(struct blkg_policy_data *pd) -{ - struct throtl_grp *tg = pd_to_tg(pd); - - tg->bps[READ][LIMIT_LOW] = 0; - tg->bps[WRITE][LIMIT_LOW] = 0; - tg->iops[READ][LIMIT_LOW] = 0; - tg->iops[WRITE][LIMIT_LOW] = 0; - - blk_throtl_update_limit_valid(tg->td); - - if (!tg->td->limit_valid[tg->td->limit_index]) - throtl_upgrade_state(tg->td); -} - static void throtl_pd_free(struct blkg_policy_data *pd) { struct throtl_grp *tg = pd_to_tg(pd); @@ -1151,8 +1010,6 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) return nr_disp; } -static bool throtl_can_upgrade(struct throtl_data *td, - struct throtl_grp *this_tg); /** * throtl_pending_timer_fn - timer function for service_queue->pending_timer * @t: the pending_timer member of the throtl_service_queue being serviced @@ -1189,9 +1046,6 @@ static void throtl_pending_timer_fn(struct timer_list *t) if (!q->root_blkg) goto out_unlock; - if (throtl_can_upgrade(td, NULL)) - throtl_upgrade_state(td); - again: parent_sq = sq->parent_sq; dispatched = false; @@ -1331,22 +1185,12 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global) blkg_for_each_descendant_pre(blkg, pos_css, global ? tg->td->queue->root_blkg : tg_to_blkg(tg)) { struct throtl_grp *this_tg = blkg_to_tg(blkg); - struct throtl_grp *parent_tg; tg_update_has_rules(this_tg); /* ignore root/second level */ if (!cgroup_subsys_on_dfl(io_cgrp_subsys) || !blkg->parent || !blkg->parent->parent) continue; - parent_tg = blkg_to_tg(blkg->parent); - /* - * make sure all children has lower idle time threshold and - * higher latency target - */ - this_tg->idletime_threshold = min(this_tg->idletime_threshold, - parent_tg->idletime_threshold); - this_tg->latency_target = max(this_tg->latency_target, - parent_tg->latency_target); } rcu_read_unlock(); @@ -1444,25 +1288,25 @@ static int tg_print_rwstat_recursive(struct seq_file *sf, void *v) static struct cftype throtl_legacy_files[] = { { .name = "throttle.read_bps_device", - .private = offsetof(struct throtl_grp, bps[READ][LIMIT_MAX]), + .private = offsetof(struct throtl_grp, bps[READ]), .seq_show = tg_print_conf_u64, .write = tg_set_conf_u64, }, { .name = "throttle.write_bps_device", - .private = offsetof(struct throtl_grp, bps[WRITE][LIMIT_MAX]), + .private = offsetof(struct throtl_grp, bps[WRITE]), .seq_show = tg_print_conf_u64, .write = tg_set_conf_u64, }, { .name = "throttle.read_iops_device", - .private = offsetof(struct throtl_grp, iops[READ][LIMIT_MAX]), + .private = offsetof(struct throtl_grp, iops[READ]), .seq_show = tg_print_conf_uint, .write = tg_set_conf_uint, }, { .name = "throttle.write_iops_device", - .private = offsetof(struct throtl_grp, iops[WRITE][LIMIT_MAX]), + .private = offsetof(struct throtl_grp, iops[WRITE]), .seq_show = tg_print_conf_uint, .write = tg_set_conf_uint, }, @@ -1500,55 +1344,36 @@ static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd, if (!dname) return 0; - if (off == LIMIT_LOW) { - bps_dft = 0; - iops_dft = 0; - } else { - bps_dft = U64_MAX; - iops_dft = UINT_MAX; - } + bps_dft = U64_MAX; + iops_dft = UINT_MAX; - if (tg->bps_conf[READ][off] == bps_dft && - tg->bps_conf[WRITE][off] == bps_dft && - tg->iops_conf[READ][off] == iops_dft && - tg->iops_conf[WRITE][off] == iops_dft && - (off != LIMIT_LOW || - (tg->idletime_threshold_conf == DFL_IDLE_THRESHOLD && - tg->latency_target_conf == DFL_LATENCY_TARGET))) + if (tg->bps_conf[READ] == bps_dft && + tg->bps_conf[WRITE] == bps_dft && + tg->iops_conf[READ] == iops_dft && + tg->iops_conf[WRITE] == iops_dft) return 0; seq_printf(sf, "%s", dname); - if (tg->bps_conf[READ][off] == U64_MAX) + if (tg->bps_conf[READ] == U64_MAX) seq_printf(sf, " rbps=max"); else - seq_printf(sf, " rbps=%llu", tg->bps_conf[READ][off]); + seq_printf(sf, " rbps=%llu", tg->bps_conf[READ]); - if (tg->bps_conf[WRITE][off] == U64_MAX) + if (tg->bps_conf[WRITE] == U64_MAX) seq_printf(sf, " wbps=max"); else - seq_printf(sf, " wbps=%llu", tg->bps_conf[WRITE][off]); + seq_printf(sf, " wbps=%llu", tg->bps_conf[WRITE]); - if (tg->iops_conf[READ][off] == UINT_MAX) + if (tg->iops_conf[READ] == UINT_MAX) seq_printf(sf, " riops=max"); else - seq_printf(sf, " riops=%u", tg->iops_conf[READ][off]); + seq_printf(sf, " riops=%u", tg->iops_conf[READ]); - if (tg->iops_conf[WRITE][off] == UINT_MAX) + if (tg->iops_conf[WRITE] == UINT_MAX) seq_printf(sf, " wiops=max"); else - seq_printf(sf, " wiops=%u", tg->iops_conf[WRITE][off]); + seq_printf(sf, " wiops=%u", tg->iops_conf[WRITE]); - if (off == LIMIT_LOW) { - if (tg->idletime_threshold_conf == ULONG_MAX) - seq_printf(sf, " idle=max"); - else - seq_printf(sf, " idle=%lu", tg->idletime_threshold_conf); - - if (tg->latency_target_conf == ULONG_MAX) - seq_printf(sf, " latency=max"); - else - seq_printf(sf, " latency=%lu", tg->latency_target_conf); - } seq_printf(sf, "\n"); return 0; } @@ -1567,10 +1392,7 @@ static ssize_t tg_set_limit(struct kernfs_open_file *of, struct blkg_conf_ctx ctx; struct throtl_grp *tg; u64 v[4]; - unsigned long idle_time; - unsigned long latency_time; int ret; - int index = of_cft(of)->private; blkg_conf_init(&ctx, buf); @@ -1581,13 +1403,11 @@ static ssize_t tg_set_limit(struct kernfs_open_file *of, tg = blkg_to_tg(ctx.blkg); tg_update_carryover(tg); - v[0] = tg->bps_conf[READ][index]; - v[1] = tg->bps_conf[WRITE][index]; - v[2] = tg->iops_conf[READ][index]; - v[3] = tg->iops_conf[WRITE][index]; + v[0] = tg->bps[READ]; + v[1] = tg->bps[WRITE]; + v[2] = tg->iops[READ]; + v[3] = tg->iops[WRITE]; - idle_time = tg->idletime_threshold_conf; - latency_time = tg->latency_target_conf; while (true) { char tok[27]; /* wiops=18446744073709551616 */ char *p; @@ -1619,60 +1439,16 @@ static ssize_t tg_set_limit(struct kernfs_open_file *of, v[2] = min_t(u64, val, UINT_MAX); else if (!strcmp(tok, "wiops") && val > 1) v[3] = min_t(u64, val, UINT_MAX); - else if (off == LIMIT_LOW && !strcmp(tok, "idle")) - idle_time = val; - else if (off == LIMIT_LOW && !strcmp(tok, "latency")) - latency_time = val; else goto out_finish; } - tg->bps_conf[READ][index] = v[0]; - tg->bps_conf[WRITE][index] = v[1]; - tg->iops_conf[READ][index] = v[2]; - tg->iops_conf[WRITE][index] = v[3]; + tg->bps[READ] = v[0]; + tg->bps[WRITE] = v[1]; + tg->iops[READ] = v[2]; + tg->iops[WRITE] = v[3]; - if (index == LIMIT_MAX) { - tg->bps[READ][index] = v[0]; - tg->bps[WRITE][index] = v[1]; - tg->iops[READ][index] = v[2]; - tg->iops[WRITE][index] = v[3]; - } - tg->bps[READ][LIMIT_LOW] = min(tg->bps_conf[READ][LIMIT_LOW], - tg->bps_conf[READ][LIMIT_MAX]); - tg->bps[WRITE][LIMIT_LOW] = min(tg->bps_conf[WRITE][LIMIT_LOW], - tg->bps_conf[WRITE][LIMIT_MAX]); - tg->iops[READ][LIMIT_LOW] = min(tg->iops_conf[READ][LIMIT_LOW], - tg->iops_conf[READ][LIMIT_MAX]); - tg->iops[WRITE][LIMIT_LOW] = min(tg->iops_conf[WRITE][LIMIT_LOW], - tg->iops_conf[WRITE][LIMIT_MAX]); - tg->idletime_threshold_conf = idle_time; - tg->latency_target_conf = latency_time; - - /* force user to configure all settings for low limit */ - if (!(tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW] || - tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) || - tg->idletime_threshold_conf == DFL_IDLE_THRESHOLD || - tg->latency_target_conf == DFL_LATENCY_TARGET) { - tg->bps[READ][LIMIT_LOW] = 0; - tg->bps[WRITE][LIMIT_LOW] = 0; - tg->iops[READ][LIMIT_LOW] = 0; - tg->iops[WRITE][LIMIT_LOW] = 0; - tg->idletime_threshold = DFL_IDLE_THRESHOLD; - tg->latency_target = DFL_LATENCY_TARGET; - } else if (index == LIMIT_LOW) { - tg->idletime_threshold = tg->idletime_threshold_conf; - tg->latency_target = tg->latency_target_conf; - } - - blk_throtl_update_limit_valid(tg->td); - if (tg->td->limit_valid[LIMIT_LOW]) { - if (index == LIMIT_LOW) - tg->td->limit_index = LIMIT_LOW; - } else - tg->td->limit_index = LIMIT_MAX; - tg_conf_updated(tg, index == LIMIT_LOW && - tg->td->limit_valid[LIMIT_LOW]); + tg_conf_updated(tg, false); ret = 0; out_finish: blkg_conf_exit(&ctx); @@ -1680,21 +1456,11 @@ out_finish: } static struct cftype throtl_files[] = { -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW - { - .name = "low", - .flags = CFTYPE_NOT_ON_ROOT, - .seq_show = tg_print_limit, - .write = tg_set_limit, - .private = LIMIT_LOW, - }, -#endif { .name = "max", .flags = CFTYPE_NOT_ON_ROOT, .seq_show = tg_print_limit, .write = tg_set_limit, - .private = LIMIT_MAX, }, { } /* terminate */ }; @@ -1713,7 +1479,6 @@ struct blkcg_policy blkcg_policy_throtl = { .pd_alloc_fn = throtl_pd_alloc, .pd_init_fn = throtl_pd_init, .pd_online_fn = throtl_pd_online, - .pd_offline_fn = throtl_pd_offline, .pd_free_fn = throtl_pd_free, }; @@ -1762,418 +1527,6 @@ void blk_throtl_cancel_bios(struct gendisk *disk) spin_unlock_irq(&q->queue_lock); } -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW -static unsigned long __tg_last_low_overflow_time(struct throtl_grp *tg) -{ - unsigned long rtime = jiffies, wtime = jiffies; - - if (tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW]) - rtime = tg->last_low_overflow_time[READ]; - if (tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) - wtime = tg->last_low_overflow_time[WRITE]; - return min(rtime, wtime); -} - -static unsigned long tg_last_low_overflow_time(struct throtl_grp *tg) -{ - struct throtl_service_queue *parent_sq; - struct throtl_grp *parent = tg; - unsigned long ret = __tg_last_low_overflow_time(tg); - - while (true) { - parent_sq = parent->service_queue.parent_sq; - parent = sq_to_tg(parent_sq); - if (!parent) - break; - - /* - * The parent doesn't have low limit, it always reaches low - * limit. Its overflow time is useless for children - */ - if (!parent->bps[READ][LIMIT_LOW] && - !parent->iops[READ][LIMIT_LOW] && - !parent->bps[WRITE][LIMIT_LOW] && - !parent->iops[WRITE][LIMIT_LOW]) - continue; - if (time_after(__tg_last_low_overflow_time(parent), ret)) - ret = __tg_last_low_overflow_time(parent); - } - return ret; -} - -static bool throtl_tg_is_idle(struct throtl_grp *tg) -{ - /* - * cgroup is idle if: - * - single idle is too long, longer than a fixed value (in case user - * configure a too big threshold) or 4 times of idletime threshold - * - average think time is more than threshold - * - IO latency is largely below threshold - */ - unsigned long time; - bool ret; - - time = min_t(unsigned long, MAX_IDLE_TIME, 4 * tg->idletime_threshold); - ret = tg->latency_target == DFL_LATENCY_TARGET || - tg->idletime_threshold == DFL_IDLE_THRESHOLD || - (blk_time_get_ns() >> 10) - tg->last_finish_time > time || - tg->avg_idletime > tg->idletime_threshold || - (tg->latency_target && tg->bio_cnt && - tg->bad_bio_cnt * 5 < tg->bio_cnt); - throtl_log(&tg->service_queue, - "avg_idle=%ld, idle_threshold=%ld, bad_bio=%d, total_bio=%d, is_idle=%d, scale=%d", - tg->avg_idletime, tg->idletime_threshold, tg->bad_bio_cnt, - tg->bio_cnt, ret, tg->td->scale); - return ret; -} - -static bool throtl_low_limit_reached(struct throtl_grp *tg, int rw) -{ - struct throtl_service_queue *sq = &tg->service_queue; - bool limit = tg->bps[rw][LIMIT_LOW] || tg->iops[rw][LIMIT_LOW]; - - /* - * if low limit is zero, low limit is always reached. - * if low limit is non-zero, we can check if there is any request - * is queued to determine if low limit is reached as we throttle - * request according to limit. - */ - return !limit || sq->nr_queued[rw]; -} - -static bool throtl_tg_can_upgrade(struct throtl_grp *tg) -{ - /* - * cgroup reaches low limit when low limit of READ and WRITE are - * both reached, it's ok to upgrade to next limit if cgroup reaches - * low limit - */ - if (throtl_low_limit_reached(tg, READ) && - throtl_low_limit_reached(tg, WRITE)) - return true; - - if (time_after_eq(jiffies, - tg_last_low_overflow_time(tg) + tg->td->throtl_slice) && - throtl_tg_is_idle(tg)) - return true; - return false; -} - -static bool throtl_hierarchy_can_upgrade(struct throtl_grp *tg) -{ - while (true) { - if (throtl_tg_can_upgrade(tg)) - return true; - tg = sq_to_tg(tg->service_queue.parent_sq); - if (!tg || !tg_to_blkg(tg)->parent) - return false; - } - return false; -} - -static bool throtl_can_upgrade(struct throtl_data *td, - struct throtl_grp *this_tg) -{ - struct cgroup_subsys_state *pos_css; - struct blkcg_gq *blkg; - - if (td->limit_index != LIMIT_LOW) - return false; - - if (time_before(jiffies, td->low_downgrade_time + td->throtl_slice)) - return false; - - rcu_read_lock(); - blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { - struct throtl_grp *tg = blkg_to_tg(blkg); - - if (tg == this_tg) - continue; - if (!list_empty(&tg_to_blkg(tg)->blkcg->css.children)) - continue; - if (!throtl_hierarchy_can_upgrade(tg)) { - rcu_read_unlock(); - return false; - } - } - rcu_read_unlock(); - return true; -} - -static void throtl_upgrade_check(struct throtl_grp *tg) -{ - unsigned long now = jiffies; - - if (tg->td->limit_index != LIMIT_LOW) - return; - - if (time_after(tg->last_check_time + tg->td->throtl_slice, now)) - return; - - tg->last_check_time = now; - - if (!time_after_eq(now, - __tg_last_low_overflow_time(tg) + tg->td->throtl_slice)) - return; - - if (throtl_can_upgrade(tg->td, NULL)) - throtl_upgrade_state(tg->td); -} - -static void throtl_upgrade_state(struct throtl_data *td) -{ - struct cgroup_subsys_state *pos_css; - struct blkcg_gq *blkg; - - throtl_log(&td->service_queue, "upgrade to max"); - td->limit_index = LIMIT_MAX; - td->low_upgrade_time = jiffies; - td->scale = 0; - rcu_read_lock(); - blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { - struct throtl_grp *tg = blkg_to_tg(blkg); - struct throtl_service_queue *sq = &tg->service_queue; - - tg->disptime = jiffies - 1; - throtl_select_dispatch(sq); - throtl_schedule_next_dispatch(sq, true); - } - rcu_read_unlock(); - throtl_select_dispatch(&td->service_queue); - throtl_schedule_next_dispatch(&td->service_queue, true); - queue_work(kthrotld_workqueue, &td->dispatch_work); -} - -static void throtl_downgrade_state(struct throtl_data *td) -{ - td->scale /= 2; - - throtl_log(&td->service_queue, "downgrade, scale %d", td->scale); - if (td->scale) { - td->low_upgrade_time = jiffies - td->scale * td->throtl_slice; - return; - } - - td->limit_index = LIMIT_LOW; - td->low_downgrade_time = jiffies; -} - -static bool throtl_tg_can_downgrade(struct throtl_grp *tg) -{ - struct throtl_data *td = tg->td; - unsigned long now = jiffies; - - /* - * If cgroup is below low limit, consider downgrade and throttle other - * cgroups - */ - if (time_after_eq(now, tg_last_low_overflow_time(tg) + - td->throtl_slice) && - (!throtl_tg_is_idle(tg) || - !list_empty(&tg_to_blkg(tg)->blkcg->css.children))) - return true; - return false; -} - -static bool throtl_hierarchy_can_downgrade(struct throtl_grp *tg) -{ - struct throtl_data *td = tg->td; - - if (time_before(jiffies, td->low_upgrade_time + td->throtl_slice)) - return false; - - while (true) { - if (!throtl_tg_can_downgrade(tg)) - return false; - tg = sq_to_tg(tg->service_queue.parent_sq); - if (!tg || !tg_to_blkg(tg)->parent) - break; - } - return true; -} - -static void throtl_downgrade_check(struct throtl_grp *tg) -{ - uint64_t bps; - unsigned int iops; - unsigned long elapsed_time; - unsigned long now = jiffies; - - if (tg->td->limit_index != LIMIT_MAX || - !tg->td->limit_valid[LIMIT_LOW]) - return; - if (!list_empty(&tg_to_blkg(tg)->blkcg->css.children)) - return; - if (time_after(tg->last_check_time + tg->td->throtl_slice, now)) - return; - - elapsed_time = now - tg->last_check_time; - tg->last_check_time = now; - - if (time_before(now, tg_last_low_overflow_time(tg) + - tg->td->throtl_slice)) - return; - - if (tg->bps[READ][LIMIT_LOW]) { - bps = tg->last_bytes_disp[READ] * HZ; - do_div(bps, elapsed_time); - if (bps >= tg->bps[READ][LIMIT_LOW]) - tg->last_low_overflow_time[READ] = now; - } - - if (tg->bps[WRITE][LIMIT_LOW]) { - bps = tg->last_bytes_disp[WRITE] * HZ; - do_div(bps, elapsed_time); - if (bps >= tg->bps[WRITE][LIMIT_LOW]) - tg->last_low_overflow_time[WRITE] = now; - } - - if (tg->iops[READ][LIMIT_LOW]) { - iops = tg->last_io_disp[READ] * HZ / elapsed_time; - if (iops >= tg->iops[READ][LIMIT_LOW]) - tg->last_low_overflow_time[READ] = now; - } - - if (tg->iops[WRITE][LIMIT_LOW]) { - iops = tg->last_io_disp[WRITE] * HZ / elapsed_time; - if (iops >= tg->iops[WRITE][LIMIT_LOW]) - tg->last_low_overflow_time[WRITE] = now; - } - - /* - * If cgroup is below low limit, consider downgrade and throttle other - * cgroups - */ - if (throtl_hierarchy_can_downgrade(tg)) - throtl_downgrade_state(tg->td); - - tg->last_bytes_disp[READ] = 0; - tg->last_bytes_disp[WRITE] = 0; - tg->last_io_disp[READ] = 0; - tg->last_io_disp[WRITE] = 0; -} - -static void blk_throtl_update_idletime(struct throtl_grp *tg) -{ - unsigned long now; - unsigned long last_finish_time = tg->last_finish_time; - - if (last_finish_time == 0) - return; - - now = blk_time_get_ns() >> 10; - if (now <= last_finish_time || - last_finish_time == tg->checked_last_finish_time) - return; - - tg->avg_idletime = (tg->avg_idletime * 7 + now - last_finish_time) >> 3; - tg->checked_last_finish_time = last_finish_time; -} - -static void throtl_update_latency_buckets(struct throtl_data *td) -{ - struct avg_latency_bucket avg_latency[2][LATENCY_BUCKET_SIZE]; - int i, cpu, rw; - unsigned long last_latency[2] = { 0 }; - unsigned long latency[2]; - - if (!blk_queue_nonrot(td->queue) || !td->limit_valid[LIMIT_LOW]) - return; - if (time_before(jiffies, td->last_calculate_time + HZ)) - return; - td->last_calculate_time = jiffies; - - memset(avg_latency, 0, sizeof(avg_latency)); - for (rw = READ; rw <= WRITE; rw++) { - for (i = 0; i < LATENCY_BUCKET_SIZE; i++) { - struct latency_bucket *tmp = &td->tmp_buckets[rw][i]; - - for_each_possible_cpu(cpu) { - struct latency_bucket *bucket; - - /* this isn't race free, but ok in practice */ - bucket = per_cpu_ptr(td->latency_buckets[rw], - cpu); - tmp->total_latency += bucket[i].total_latency; - tmp->samples += bucket[i].samples; - bucket[i].total_latency = 0; - bucket[i].samples = 0; - } - - if (tmp->samples >= 32) { - int samples = tmp->samples; - - latency[rw] = tmp->total_latency; - - tmp->total_latency = 0; - tmp->samples = 0; - latency[rw] /= samples; - if (latency[rw] == 0) - continue; - avg_latency[rw][i].latency = latency[rw]; - } - } - } - - for (rw = READ; rw <= WRITE; rw++) { - for (i = 0; i < LATENCY_BUCKET_SIZE; i++) { - if (!avg_latency[rw][i].latency) { - if (td->avg_buckets[rw][i].latency < last_latency[rw]) - td->avg_buckets[rw][i].latency = - last_latency[rw]; - continue; - } - - if (!td->avg_buckets[rw][i].valid) - latency[rw] = avg_latency[rw][i].latency; - else - latency[rw] = (td->avg_buckets[rw][i].latency * 7 + - avg_latency[rw][i].latency) >> 3; - - td->avg_buckets[rw][i].latency = max(latency[rw], - last_latency[rw]); - td->avg_buckets[rw][i].valid = true; - last_latency[rw] = td->avg_buckets[rw][i].latency; - } - } - - for (i = 0; i < LATENCY_BUCKET_SIZE; i++) - throtl_log(&td->service_queue, - "Latency bucket %d: read latency=%ld, read valid=%d, " - "write latency=%ld, write valid=%d", i, - td->avg_buckets[READ][i].latency, - td->avg_buckets[READ][i].valid, - td->avg_buckets[WRITE][i].latency, - td->avg_buckets[WRITE][i].valid); -} -#else -static inline void throtl_update_latency_buckets(struct throtl_data *td) -{ -} - -static void blk_throtl_update_idletime(struct throtl_grp *tg) -{ -} - -static void throtl_downgrade_check(struct throtl_grp *tg) -{ -} - -static void throtl_upgrade_check(struct throtl_grp *tg) -{ -} - -static bool throtl_can_upgrade(struct throtl_data *td, - struct throtl_grp *this_tg) -{ - return false; -} - -static void throtl_upgrade_state(struct throtl_data *td) -{ -} -#endif - bool __blk_throtl_bio(struct bio *bio) { struct request_queue *q = bdev_get_queue(bio->bi_bdev); @@ -2186,21 +1539,12 @@ bool __blk_throtl_bio(struct bio *bio) struct throtl_data *td = tg->td; rcu_read_lock(); - spin_lock_irq(&q->queue_lock); - - throtl_update_latency_buckets(td); - - blk_throtl_update_idletime(tg); - sq = &tg->service_queue; -again: while (true) { if (tg->last_low_overflow_time[rw] == 0) tg->last_low_overflow_time[rw] = jiffies; - throtl_downgrade_check(tg); - throtl_upgrade_check(tg); /* throtl is FIFO - if bios are already queued, should queue */ if (sq->nr_queued[rw]) break; @@ -2208,10 +1552,6 @@ again: /* if above limits, break to queue */ if (!tg_may_dispatch(tg, bio, NULL)) { tg->last_low_overflow_time[rw] = jiffies; - if (throtl_can_upgrade(td, tg)) { - throtl_upgrade_state(td); - goto again; - } break; } @@ -2271,101 +1611,12 @@ again: } out_unlock: -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW - if (throttled || !td->track_bio_latency) - bio->bi_issue.value |= BIO_ISSUE_THROTL_SKIP_LATENCY; -#endif spin_unlock_irq(&q->queue_lock); rcu_read_unlock(); return throttled; } -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW -static void throtl_track_latency(struct throtl_data *td, sector_t size, - enum req_op op, unsigned long time) -{ - const bool rw = op_is_write(op); - struct latency_bucket *latency; - int index; - - if (!td || td->limit_index != LIMIT_LOW || - !(op == REQ_OP_READ || op == REQ_OP_WRITE) || - !blk_queue_nonrot(td->queue)) - return; - - index = request_bucket_index(size); - - latency = get_cpu_ptr(td->latency_buckets[rw]); - latency[index].total_latency += time; - latency[index].samples++; - put_cpu_ptr(td->latency_buckets[rw]); -} - -void blk_throtl_stat_add(struct request *rq, u64 time_ns) -{ - struct request_queue *q = rq->q; - struct throtl_data *td = q->td; - - throtl_track_latency(td, blk_rq_stats_sectors(rq), req_op(rq), - time_ns >> 10); -} - -void blk_throtl_bio_endio(struct bio *bio) -{ - struct blkcg_gq *blkg; - struct throtl_grp *tg; - u64 finish_time_ns; - unsigned long finish_time; - unsigned long start_time; - unsigned long lat; - int rw = bio_data_dir(bio); - - blkg = bio->bi_blkg; - if (!blkg) - return; - tg = blkg_to_tg(blkg); - if (!tg->td->limit_valid[LIMIT_LOW]) - return; - - finish_time_ns = blk_time_get_ns(); - tg->last_finish_time = finish_time_ns >> 10; - - start_time = bio_issue_time(&bio->bi_issue) >> 10; - finish_time = __bio_issue_time(finish_time_ns) >> 10; - if (!start_time || finish_time <= start_time) - return; - - lat = finish_time - start_time; - /* this is only for bio based driver */ - if (!(bio->bi_issue.value & BIO_ISSUE_THROTL_SKIP_LATENCY)) - throtl_track_latency(tg->td, bio_issue_size(&bio->bi_issue), - bio_op(bio), lat); - - if (tg->latency_target && lat >= tg->td->filtered_latency) { - int bucket; - unsigned int threshold; - - bucket = request_bucket_index(bio_issue_size(&bio->bi_issue)); - threshold = tg->td->avg_buckets[rw][bucket].latency + - tg->latency_target; - if (lat > threshold) - tg->bad_bio_cnt++; - /* - * Not race free, could get wrong count, which means cgroups - * will be throttled - */ - tg->bio_cnt++; - } - - if (time_after(jiffies, tg->bio_cnt_reset_time) || tg->bio_cnt > 1024) { - tg->bio_cnt_reset_time = tg->td->throtl_slice + jiffies; - tg->bio_cnt /= 2; - tg->bad_bio_cnt /= 2; - } -} -#endif - int blk_throtl_init(struct gendisk *disk) { struct request_queue *q = disk->queue; @@ -2375,19 +1626,6 @@ int blk_throtl_init(struct gendisk *disk) td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node); if (!td) return -ENOMEM; - td->latency_buckets[READ] = __alloc_percpu(sizeof(struct latency_bucket) * - LATENCY_BUCKET_SIZE, __alignof__(u64)); - if (!td->latency_buckets[READ]) { - kfree(td); - return -ENOMEM; - } - td->latency_buckets[WRITE] = __alloc_percpu(sizeof(struct latency_bucket) * - LATENCY_BUCKET_SIZE, __alignof__(u64)); - if (!td->latency_buckets[WRITE]) { - free_percpu(td->latency_buckets[READ]); - kfree(td); - return -ENOMEM; - } INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); throtl_service_queue_init(&td->service_queue); @@ -2395,18 +1633,10 @@ int blk_throtl_init(struct gendisk *disk) q->td = td; td->queue = q; - td->limit_valid[LIMIT_MAX] = true; - td->limit_index = LIMIT_MAX; - td->low_upgrade_time = jiffies; - td->low_downgrade_time = jiffies; - /* activate policy */ ret = blkcg_activate_policy(disk, &blkcg_policy_throtl); - if (ret) { - free_percpu(td->latency_buckets[READ]); - free_percpu(td->latency_buckets[WRITE]); + if (ret) kfree(td); - } return ret; } @@ -2418,8 +1648,6 @@ void blk_throtl_exit(struct gendisk *disk) del_timer_sync(&q->td->service_queue.pending_timer); throtl_shutdown_wq(q); blkcg_deactivate_policy(disk, &blkcg_policy_throtl); - free_percpu(q->td->latency_buckets[READ]); - free_percpu(q->td->latency_buckets[WRITE]); kfree(q->td); } @@ -2427,58 +1655,18 @@ void blk_throtl_register(struct gendisk *disk) { struct request_queue *q = disk->queue; struct throtl_data *td; - int i; td = q->td; BUG_ON(!td); - if (blk_queue_nonrot(q)) { + if (blk_queue_nonrot(q)) td->throtl_slice = DFL_THROTL_SLICE_SSD; - td->filtered_latency = LATENCY_FILTERED_SSD; - } else { + else td->throtl_slice = DFL_THROTL_SLICE_HD; - td->filtered_latency = LATENCY_FILTERED_HD; - for (i = 0; i < LATENCY_BUCKET_SIZE; i++) { - td->avg_buckets[READ][i].latency = DFL_HD_BASELINE_LATENCY; - td->avg_buckets[WRITE][i].latency = DFL_HD_BASELINE_LATENCY; - } - } -#ifndef CONFIG_BLK_DEV_THROTTLING_LOW - /* if no low limit, use previous default */ - td->throtl_slice = DFL_THROTL_SLICE_HD; - -#else td->track_bio_latency = !queue_is_mq(q); if (!td->track_bio_latency) blk_stat_enable_accounting(q); -#endif -} - -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW -ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page) -{ - if (!q->td) - return -EINVAL; - return sprintf(page, "%u\n", jiffies_to_msecs(q->td->throtl_slice)); -} - -ssize_t blk_throtl_sample_time_store(struct request_queue *q, - const char *page, size_t count) -{ - unsigned long v; - unsigned long t; - - if (!q->td) - return -EINVAL; - if (kstrtoul(page, 10, &v)) - return -EINVAL; - t = msecs_to_jiffies(v); - if (t == 0 || t > MAX_THROTL_SLICE) - return -EINVAL; - q->td->throtl_slice = t; - return count; } -#endif static int __init throtl_init(void) { diff --git a/block/blk-throttle.h b/block/blk-throttle.h index bffbc9cfc8ab..32503fd83a84 100644 --- a/block/blk-throttle.h +++ b/block/blk-throttle.h @@ -58,12 +58,6 @@ enum tg_state_flags { THROTL_TG_CANCELING = 1 << 2, /* starts to cancel bio */ }; -enum { - LIMIT_LOW, - LIMIT_MAX, - LIMIT_CNT, -}; - struct throtl_grp { /* must be the first member */ struct blkg_policy_data pd; @@ -102,14 +96,14 @@ struct throtl_grp { bool has_rules_iops[2]; /* internally used bytes per second rate limits */ - uint64_t bps[2][LIMIT_CNT]; + uint64_t bps[2]; /* user configured bps limits */ - uint64_t bps_conf[2][LIMIT_CNT]; + uint64_t bps_conf[2]; /* internally used IOPS limits */ - unsigned int iops[2][LIMIT_CNT]; + unsigned int iops[2]; /* user configured IOPS limits */ - unsigned int iops_conf[2][LIMIT_CNT]; + unsigned int iops_conf[2]; /* Number of bytes dispatched in current slice */ uint64_t bytes_disp[2]; @@ -132,22 +126,10 @@ struct throtl_grp { unsigned long last_check_time; - unsigned long latency_target; /* us */ - unsigned long latency_target_conf; /* us */ /* When did we start a new slice */ unsigned long slice_start[2]; unsigned long slice_end[2]; - unsigned long last_finish_time; /* ns / 1024 */ - unsigned long checked_last_finish_time; /* ns / 1024 */ - unsigned long avg_idletime; /* ns / 1024 */ - unsigned long idletime_threshold; /* us */ - unsigned long idletime_threshold_conf; /* us */ - - unsigned int bio_cnt; /* total bios */ - unsigned int bad_bio_cnt; /* bios exceeding latency threshold */ - unsigned long bio_cnt_reset_time; - struct blkg_rwstat stat_bytes; struct blkg_rwstat stat_ios; }; diff --git a/block/blk.h b/block/blk.h index 3870bdcd5cad..6e94c10af798 100644 --- a/block/blk.h +++ b/block/blk.h @@ -388,17 +388,6 @@ static inline void ioc_clear_queue(struct request_queue *q) } #endif /* CONFIG_BLK_ICQ */ -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW -extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page); -extern ssize_t blk_throtl_sample_time_store(struct request_queue *q, - const char *page, size_t count); -extern void blk_throtl_bio_endio(struct bio *bio); -extern void blk_throtl_stat_add(struct request *rq, u64 time); -#else -static inline void blk_throtl_bio_endio(struct bio *bio) { } -static inline void blk_throtl_stat_add(struct request *rq, u64 time) { } -#endif - struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q); static inline bool blk_queue_may_bounce(struct request_queue *q) |