Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Interface for controlling IO bandwidth on a request queue |
| 3 | * |
| 4 | * Copyright (C) 2010 Vivek Goyal <vgoyal@redhat.com> |
| 5 | */ |
| 6 | |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/slab.h> |
| 9 | #include <linux/blkdev.h> |
| 10 | #include <linux/bio.h> |
| 11 | #include <linux/blktrace_api.h> |
Tejun Heo | eea8f41 | 2015-05-22 17:13:17 -0400 | [diff] [blame] | 12 | #include <linux/blk-cgroup.h> |
Tejun Heo | bc9fcbf | 2011-10-19 14:31:18 +0200 | [diff] [blame] | 13 | #include "blk.h" |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 14 | |
| 15 | /* Max dispatch from a group in 1 round */ |
| 16 | static int throtl_grp_quantum = 8; |
| 17 | |
| 18 | /* Total max dispatch from all groups in one round */ |
| 19 | static int throtl_quantum = 32; |
| 20 | |
Shaohua Li | d61fcfa | 2017-03-27 10:51:38 -0700 | [diff] [blame] | 21 | /* Throttling is performed over a slice and after that slice is renewed */ |
| 22 | #define DFL_THROTL_SLICE_HD (HZ / 10) |
| 23 | #define DFL_THROTL_SLICE_SSD (HZ / 50) |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 24 | #define MAX_THROTL_SLICE (HZ) |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 25 | #define MAX_IDLE_TIME (5L * 1000 * 1000) /* 5 s */ |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 26 | #define MIN_THROTL_BPS (320 * 1024) |
| 27 | #define MIN_THROTL_IOPS (10) |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 28 | #define DFL_LATENCY_TARGET (-1L) |
| 29 | #define DFL_IDLE_THRESHOLD (0) |
Shaohua Li | 6679a90 | 2017-06-06 12:40:43 -0700 | [diff] [blame] | 30 | #define DFL_HD_BASELINE_LATENCY (4000L) /* 4ms */ |
| 31 | #define LATENCY_FILTERED_SSD (0) |
| 32 | /* |
| 33 | * For HD, very small latency comes from sequential IO. Such IO is helpless to |
| 34 | * help determine if its IO is impacted by others, hence we ignore the IO |
| 35 | */ |
| 36 | #define LATENCY_FILTERED_HD (1000L) /* 1ms */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 37 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 38 | #define SKIP_LATENCY (((u64)1) << BLK_STAT_RES_SHIFT) |
| 39 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 40 | static struct blkcg_policy blkcg_policy_throtl; |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 41 | |
Vivek Goyal | 450adcb | 2011-03-01 13:40:54 -0500 | [diff] [blame] | 42 | /* A workqueue to queue throttle related work */ |
| 43 | static struct workqueue_struct *kthrotld_workqueue; |
Vivek Goyal | 450adcb | 2011-03-01 13:40:54 -0500 | [diff] [blame] | 44 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 45 | /* |
| 46 | * To implement hierarchical throttling, throtl_grps form a tree and bios |
| 47 | * are dispatched upwards level by level until they reach the top and get |
| 48 | * issued. When dispatching bios from the children and local group at each |
| 49 | * level, if the bios are dispatched into a single bio_list, there's a risk |
| 50 | * of a local or child group which can queue many bios at once filling up |
| 51 | * the list starving others. |
| 52 | * |
| 53 | * To avoid such starvation, dispatched bios are queued separately |
| 54 | * according to where they came from. When they are again dispatched to |
| 55 | * the parent, they're popped in round-robin order so that no single source |
| 56 | * hogs the dispatch window. |
| 57 | * |
| 58 | * throtl_qnode is used to keep the queued bios separated by their sources. |
| 59 | * Bios are queued to throtl_qnode which in turn is queued to |
| 60 | * throtl_service_queue and then dispatched in round-robin order. |
| 61 | * |
| 62 | * It's also used to track the reference counts on blkg's. A qnode always |
| 63 | * belongs to a throtl_grp and gets queued on itself or the parent, so |
| 64 | * incrementing the reference of the associated throtl_grp when a qnode is |
| 65 | * queued and decrementing when dequeued is enough to keep the whole blkg |
| 66 | * tree pinned while bios are in flight. |
| 67 | */ |
| 68 | struct throtl_qnode { |
| 69 | struct list_head node; /* service_queue->queued[] */ |
| 70 | struct bio_list bios; /* queued bios */ |
| 71 | struct throtl_grp *tg; /* tg this qnode belongs to */ |
| 72 | }; |
| 73 | |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 74 | struct throtl_service_queue { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 75 | struct throtl_service_queue *parent_sq; /* the parent service_queue */ |
| 76 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 77 | /* |
| 78 | * Bios queued directly to this service_queue or dispatched from |
| 79 | * children throtl_grp's. |
| 80 | */ |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 81 | struct list_head queued[2]; /* throtl_qnode [READ/WRITE] */ |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 82 | unsigned int nr_queued[2]; /* number of queued bios */ |
| 83 | |
| 84 | /* |
| 85 | * RB tree of active children throtl_grp's, which are sorted by |
| 86 | * their ->disptime. |
| 87 | */ |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 88 | struct rb_root pending_tree; /* RB tree of active tgs */ |
| 89 | struct rb_node *first_pending; /* first node in the tree */ |
| 90 | unsigned int nr_pending; /* # queued in the tree */ |
| 91 | unsigned long first_pending_disptime; /* disptime of the first tg */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 92 | struct timer_list pending_timer; /* fires on first_pending_disptime */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 93 | }; |
| 94 | |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 95 | enum tg_state_flags { |
| 96 | THROTL_TG_PENDING = 1 << 0, /* on parent's pending tree */ |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 97 | THROTL_TG_WAS_EMPTY = 1 << 1, /* bio_lists[] became non-empty */ |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 98 | }; |
| 99 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 100 | #define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node) |
| 101 | |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 102 | enum { |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 103 | LIMIT_LOW, |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 104 | LIMIT_MAX, |
| 105 | LIMIT_CNT, |
| 106 | }; |
| 107 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 108 | struct throtl_grp { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 109 | /* must be the first member */ |
| 110 | struct blkg_policy_data pd; |
| 111 | |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 112 | /* active throtl group service_queue member */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 113 | struct rb_node rb_node; |
| 114 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 115 | /* throtl_data this group belongs to */ |
| 116 | struct throtl_data *td; |
| 117 | |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 118 | /* this group's service queue */ |
| 119 | struct throtl_service_queue service_queue; |
| 120 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 121 | /* |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 122 | * qnode_on_self is used when bios are directly queued to this |
| 123 | * throtl_grp so that local bios compete fairly with bios |
| 124 | * dispatched from children. qnode_on_parent is used when bios are |
| 125 | * dispatched from this throtl_grp into its parent and will compete |
| 126 | * with the sibling qnode_on_parents and the parent's |
| 127 | * qnode_on_self. |
| 128 | */ |
| 129 | struct throtl_qnode qnode_on_self[2]; |
| 130 | struct throtl_qnode qnode_on_parent[2]; |
| 131 | |
| 132 | /* |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 133 | * Dispatch time in jiffies. This is the estimated time when group |
| 134 | * will unthrottle and is ready to dispatch more bio. It is used as |
| 135 | * key to sort active groups in service tree. |
| 136 | */ |
| 137 | unsigned long disptime; |
| 138 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 139 | unsigned int flags; |
| 140 | |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 141 | /* are there any throtl rules between this group and td? */ |
| 142 | bool has_rules[2]; |
| 143 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 144 | /* internally used bytes per second rate limits */ |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 145 | uint64_t bps[2][LIMIT_CNT]; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 146 | /* user configured bps limits */ |
| 147 | uint64_t bps_conf[2][LIMIT_CNT]; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 148 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 149 | /* internally used IOPS limits */ |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 150 | unsigned int iops[2][LIMIT_CNT]; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 151 | /* user configured IOPS limits */ |
| 152 | unsigned int iops_conf[2][LIMIT_CNT]; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 153 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 154 | /* Number of bytes disptached in current slice */ |
| 155 | uint64_t bytes_disp[2]; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 156 | /* Number of bio's dispatched in current slice */ |
| 157 | unsigned int io_disp[2]; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 158 | |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 159 | unsigned long last_low_overflow_time[2]; |
| 160 | |
| 161 | uint64_t last_bytes_disp[2]; |
| 162 | unsigned int last_io_disp[2]; |
| 163 | |
| 164 | unsigned long last_check_time; |
| 165 | |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 166 | unsigned long latency_target; /* us */ |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 167 | unsigned long latency_target_conf; /* us */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 168 | /* When did we start a new slice */ |
| 169 | unsigned long slice_start[2]; |
| 170 | unsigned long slice_end[2]; |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 171 | |
| 172 | unsigned long last_finish_time; /* ns / 1024 */ |
| 173 | unsigned long checked_last_finish_time; /* ns / 1024 */ |
| 174 | unsigned long avg_idletime; /* ns / 1024 */ |
| 175 | unsigned long idletime_threshold; /* us */ |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 176 | unsigned long idletime_threshold_conf; /* us */ |
Shaohua Li | 53696b8 | 2017-03-27 15:19:43 -0700 | [diff] [blame] | 177 | |
| 178 | unsigned int bio_cnt; /* total bios */ |
| 179 | unsigned int bad_bio_cnt; /* bios exceeding latency threshold */ |
| 180 | unsigned long bio_cnt_reset_time; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 181 | }; |
| 182 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 183 | /* We measure latency for request size from <= 4k to >= 1M */ |
| 184 | #define LATENCY_BUCKET_SIZE 9 |
| 185 | |
| 186 | struct latency_bucket { |
| 187 | unsigned long total_latency; /* ns / 1024 */ |
| 188 | int samples; |
| 189 | }; |
| 190 | |
| 191 | struct avg_latency_bucket { |
| 192 | unsigned long latency; /* ns / 1024 */ |
| 193 | bool valid; |
| 194 | }; |
| 195 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 196 | struct throtl_data |
| 197 | { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 198 | /* service tree for active throtl groups */ |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 199 | struct throtl_service_queue service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 200 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 201 | struct request_queue *queue; |
| 202 | |
| 203 | /* Total Number of queued bios on READ and WRITE lists */ |
| 204 | unsigned int nr_queued[2]; |
| 205 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 206 | unsigned int throtl_slice; |
| 207 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 208 | /* Work for dispatching throttled bios */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 209 | struct work_struct dispatch_work; |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 210 | unsigned int limit_index; |
| 211 | bool limit_valid[LIMIT_CNT]; |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 212 | |
| 213 | unsigned long low_upgrade_time; |
| 214 | unsigned long low_downgrade_time; |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 215 | |
| 216 | unsigned int scale; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 217 | |
| 218 | struct latency_bucket tmp_buckets[LATENCY_BUCKET_SIZE]; |
| 219 | struct avg_latency_bucket avg_buckets[LATENCY_BUCKET_SIZE]; |
| 220 | struct latency_bucket __percpu *latency_buckets; |
| 221 | unsigned long last_calculate_time; |
Shaohua Li | 6679a90 | 2017-06-06 12:40:43 -0700 | [diff] [blame] | 222 | unsigned long filtered_latency; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 223 | |
| 224 | bool track_bio_latency; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 225 | }; |
| 226 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 227 | static void throtl_pending_timer_fn(unsigned long arg); |
| 228 | |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 229 | static inline struct throtl_grp *pd_to_tg(struct blkg_policy_data *pd) |
| 230 | { |
| 231 | return pd ? container_of(pd, struct throtl_grp, pd) : NULL; |
| 232 | } |
| 233 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 234 | static inline struct throtl_grp *blkg_to_tg(struct blkcg_gq *blkg) |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 235 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 236 | return pd_to_tg(blkg_to_pd(blkg, &blkcg_policy_throtl)); |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 237 | } |
| 238 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 239 | static inline struct blkcg_gq *tg_to_blkg(struct throtl_grp *tg) |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 240 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 241 | return pd_to_blkg(&tg->pd); |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 242 | } |
| 243 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 244 | /** |
| 245 | * sq_to_tg - return the throl_grp the specified service queue belongs to |
| 246 | * @sq: the throtl_service_queue of interest |
| 247 | * |
| 248 | * Return the throtl_grp @sq belongs to. If @sq is the top-level one |
| 249 | * embedded in throtl_data, %NULL is returned. |
| 250 | */ |
| 251 | static struct throtl_grp *sq_to_tg(struct throtl_service_queue *sq) |
| 252 | { |
| 253 | if (sq && sq->parent_sq) |
| 254 | return container_of(sq, struct throtl_grp, service_queue); |
| 255 | else |
| 256 | return NULL; |
| 257 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 258 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 259 | /** |
| 260 | * sq_to_td - return throtl_data the specified service queue belongs to |
| 261 | * @sq: the throtl_service_queue of interest |
| 262 | * |
Masahiro Yamada | b43daed | 2017-02-27 14:29:09 -0800 | [diff] [blame] | 263 | * A service_queue can be embedded in either a throtl_grp or throtl_data. |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 264 | * Determine the associated throtl_data accordingly and return it. |
| 265 | */ |
| 266 | static struct throtl_data *sq_to_td(struct throtl_service_queue *sq) |
| 267 | { |
| 268 | struct throtl_grp *tg = sq_to_tg(sq); |
| 269 | |
| 270 | if (tg) |
| 271 | return tg->td; |
| 272 | else |
| 273 | return container_of(sq, struct throtl_data, service_queue); |
| 274 | } |
| 275 | |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 276 | /* |
| 277 | * cgroup's limit in LIMIT_MAX is scaled if low limit is set. This scale is to |
| 278 | * make the IO dispatch more smooth. |
| 279 | * Scale up: linearly scale up according to lapsed time since upgrade. For |
| 280 | * every throtl_slice, the limit scales up 1/2 .low limit till the |
| 281 | * limit hits .max limit |
| 282 | * Scale down: exponentially scale down if a cgroup doesn't hit its .low limit |
| 283 | */ |
| 284 | static uint64_t throtl_adjusted_limit(uint64_t low, struct throtl_data *td) |
| 285 | { |
| 286 | /* arbitrary value to avoid too big scale */ |
| 287 | if (td->scale < 4096 && time_after_eq(jiffies, |
| 288 | td->low_upgrade_time + td->scale * td->throtl_slice)) |
| 289 | td->scale = (jiffies - td->low_upgrade_time) / td->throtl_slice; |
| 290 | |
| 291 | return low + (low >> 1) * td->scale; |
| 292 | } |
| 293 | |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 294 | static uint64_t tg_bps_limit(struct throtl_grp *tg, int rw) |
| 295 | { |
Shaohua Li | b22c417 | 2017-03-27 10:51:33 -0700 | [diff] [blame] | 296 | struct blkcg_gq *blkg = tg_to_blkg(tg); |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 297 | struct throtl_data *td; |
Shaohua Li | b22c417 | 2017-03-27 10:51:33 -0700 | [diff] [blame] | 298 | uint64_t ret; |
| 299 | |
| 300 | if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent) |
| 301 | return U64_MAX; |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 302 | |
| 303 | td = tg->td; |
| 304 | ret = tg->bps[rw][td->limit_index]; |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 305 | if (ret == 0 && td->limit_index == LIMIT_LOW) { |
| 306 | /* intermediate node or iops isn't 0 */ |
| 307 | if (!list_empty(&blkg->blkcg->css.children) || |
| 308 | tg->iops[rw][td->limit_index]) |
| 309 | return U64_MAX; |
| 310 | else |
| 311 | return MIN_THROTL_BPS; |
| 312 | } |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 313 | |
| 314 | if (td->limit_index == LIMIT_MAX && tg->bps[rw][LIMIT_LOW] && |
| 315 | tg->bps[rw][LIMIT_LOW] != tg->bps[rw][LIMIT_MAX]) { |
| 316 | uint64_t adjusted; |
| 317 | |
| 318 | adjusted = throtl_adjusted_limit(tg->bps[rw][LIMIT_LOW], td); |
| 319 | ret = min(tg->bps[rw][LIMIT_MAX], adjusted); |
| 320 | } |
Shaohua Li | b22c417 | 2017-03-27 10:51:33 -0700 | [diff] [blame] | 321 | return ret; |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 322 | } |
| 323 | |
| 324 | static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw) |
| 325 | { |
Shaohua Li | b22c417 | 2017-03-27 10:51:33 -0700 | [diff] [blame] | 326 | struct blkcg_gq *blkg = tg_to_blkg(tg); |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 327 | struct throtl_data *td; |
Shaohua Li | b22c417 | 2017-03-27 10:51:33 -0700 | [diff] [blame] | 328 | unsigned int ret; |
| 329 | |
| 330 | if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent) |
| 331 | return UINT_MAX; |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 332 | |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 333 | td = tg->td; |
| 334 | ret = tg->iops[rw][td->limit_index]; |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 335 | if (ret == 0 && tg->td->limit_index == LIMIT_LOW) { |
| 336 | /* intermediate node or bps isn't 0 */ |
| 337 | if (!list_empty(&blkg->blkcg->css.children) || |
| 338 | tg->bps[rw][td->limit_index]) |
| 339 | return UINT_MAX; |
| 340 | else |
| 341 | return MIN_THROTL_IOPS; |
| 342 | } |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 343 | |
| 344 | if (td->limit_index == LIMIT_MAX && tg->iops[rw][LIMIT_LOW] && |
| 345 | tg->iops[rw][LIMIT_LOW] != tg->iops[rw][LIMIT_MAX]) { |
| 346 | uint64_t adjusted; |
| 347 | |
| 348 | adjusted = throtl_adjusted_limit(tg->iops[rw][LIMIT_LOW], td); |
| 349 | if (adjusted > UINT_MAX) |
| 350 | adjusted = UINT_MAX; |
| 351 | ret = min_t(unsigned int, tg->iops[rw][LIMIT_MAX], adjusted); |
| 352 | } |
Shaohua Li | b22c417 | 2017-03-27 10:51:33 -0700 | [diff] [blame] | 353 | return ret; |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 354 | } |
| 355 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 356 | #define request_bucket_index(sectors) \ |
| 357 | clamp_t(int, order_base_2(sectors) - 3, 0, LATENCY_BUCKET_SIZE - 1) |
| 358 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 359 | /** |
| 360 | * throtl_log - log debug message via blktrace |
| 361 | * @sq: the service_queue being reported |
| 362 | * @fmt: printf format string |
| 363 | * @args: printf args |
| 364 | * |
| 365 | * The messages are prefixed with "throtl BLKG_NAME" if @sq belongs to a |
| 366 | * throtl_grp; otherwise, just "throtl". |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 367 | */ |
| 368 | #define throtl_log(sq, fmt, args...) do { \ |
| 369 | struct throtl_grp *__tg = sq_to_tg((sq)); \ |
| 370 | struct throtl_data *__td = sq_to_td((sq)); \ |
| 371 | \ |
| 372 | (void)__td; \ |
Shaohua Li | 59fa022 | 2016-05-09 17:22:15 -0700 | [diff] [blame] | 373 | if (likely(!blk_trace_note_message_enabled(__td->queue))) \ |
| 374 | break; \ |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 375 | if ((__tg)) { \ |
| 376 | char __pbuf[128]; \ |
| 377 | \ |
| 378 | blkg_path(tg_to_blkg(__tg), __pbuf, sizeof(__pbuf)); \ |
| 379 | blk_add_trace_msg(__td->queue, "throtl %s " fmt, __pbuf, ##args); \ |
| 380 | } else { \ |
| 381 | blk_add_trace_msg(__td->queue, "throtl " fmt, ##args); \ |
| 382 | } \ |
| 383 | } while (0) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 384 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 385 | static void throtl_qnode_init(struct throtl_qnode *qn, struct throtl_grp *tg) |
| 386 | { |
| 387 | INIT_LIST_HEAD(&qn->node); |
| 388 | bio_list_init(&qn->bios); |
| 389 | qn->tg = tg; |
| 390 | } |
| 391 | |
| 392 | /** |
| 393 | * throtl_qnode_add_bio - add a bio to a throtl_qnode and activate it |
| 394 | * @bio: bio being added |
| 395 | * @qn: qnode to add bio to |
| 396 | * @queued: the service_queue->queued[] list @qn belongs to |
| 397 | * |
| 398 | * Add @bio to @qn and put @qn on @queued if it's not already on. |
| 399 | * @qn->tg's reference count is bumped when @qn is activated. See the |
| 400 | * comment on top of throtl_qnode definition for details. |
| 401 | */ |
| 402 | static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn, |
| 403 | struct list_head *queued) |
| 404 | { |
| 405 | bio_list_add(&qn->bios, bio); |
| 406 | if (list_empty(&qn->node)) { |
| 407 | list_add_tail(&qn->node, queued); |
| 408 | blkg_get(tg_to_blkg(qn->tg)); |
| 409 | } |
| 410 | } |
| 411 | |
| 412 | /** |
| 413 | * throtl_peek_queued - peek the first bio on a qnode list |
| 414 | * @queued: the qnode list to peek |
| 415 | */ |
| 416 | static struct bio *throtl_peek_queued(struct list_head *queued) |
| 417 | { |
| 418 | struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); |
| 419 | struct bio *bio; |
| 420 | |
| 421 | if (list_empty(queued)) |
| 422 | return NULL; |
| 423 | |
| 424 | bio = bio_list_peek(&qn->bios); |
| 425 | WARN_ON_ONCE(!bio); |
| 426 | return bio; |
| 427 | } |
| 428 | |
| 429 | /** |
| 430 | * throtl_pop_queued - pop the first bio form a qnode list |
| 431 | * @queued: the qnode list to pop a bio from |
| 432 | * @tg_to_put: optional out argument for throtl_grp to put |
| 433 | * |
| 434 | * Pop the first bio from the qnode list @queued. After popping, the first |
| 435 | * qnode is removed from @queued if empty or moved to the end of @queued so |
| 436 | * that the popping order is round-robin. |
| 437 | * |
| 438 | * When the first qnode is removed, its associated throtl_grp should be put |
| 439 | * too. If @tg_to_put is NULL, this function automatically puts it; |
| 440 | * otherwise, *@tg_to_put is set to the throtl_grp to put and the caller is |
| 441 | * responsible for putting it. |
| 442 | */ |
| 443 | static struct bio *throtl_pop_queued(struct list_head *queued, |
| 444 | struct throtl_grp **tg_to_put) |
| 445 | { |
| 446 | struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); |
| 447 | struct bio *bio; |
| 448 | |
| 449 | if (list_empty(queued)) |
| 450 | return NULL; |
| 451 | |
| 452 | bio = bio_list_pop(&qn->bios); |
| 453 | WARN_ON_ONCE(!bio); |
| 454 | |
| 455 | if (bio_list_empty(&qn->bios)) { |
| 456 | list_del_init(&qn->node); |
| 457 | if (tg_to_put) |
| 458 | *tg_to_put = qn->tg; |
| 459 | else |
| 460 | blkg_put(tg_to_blkg(qn->tg)); |
| 461 | } else { |
| 462 | list_move_tail(&qn->node, queued); |
| 463 | } |
| 464 | |
| 465 | return bio; |
| 466 | } |
| 467 | |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 468 | /* init a service_queue, assumes the caller zeroed it */ |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 469 | static void throtl_service_queue_init(struct throtl_service_queue *sq) |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 470 | { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 471 | INIT_LIST_HEAD(&sq->queued[0]); |
| 472 | INIT_LIST_HEAD(&sq->queued[1]); |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 473 | sq->pending_tree = RB_ROOT; |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 474 | setup_timer(&sq->pending_timer, throtl_pending_timer_fn, |
| 475 | (unsigned long)sq); |
| 476 | } |
| 477 | |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 478 | static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node) |
| 479 | { |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 480 | struct throtl_grp *tg; |
Tejun Heo | 24bdb8e | 2015-08-18 14:55:22 -0700 | [diff] [blame] | 481 | int rw; |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 482 | |
| 483 | tg = kzalloc_node(sizeof(*tg), gfp, node); |
| 484 | if (!tg) |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 485 | return NULL; |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 486 | |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 487 | throtl_service_queue_init(&tg->service_queue); |
| 488 | |
| 489 | for (rw = READ; rw <= WRITE; rw++) { |
| 490 | throtl_qnode_init(&tg->qnode_on_self[rw], tg); |
| 491 | throtl_qnode_init(&tg->qnode_on_parent[rw], tg); |
| 492 | } |
| 493 | |
| 494 | RB_CLEAR_NODE(&tg->rb_node); |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 495 | tg->bps[READ][LIMIT_MAX] = U64_MAX; |
| 496 | tg->bps[WRITE][LIMIT_MAX] = U64_MAX; |
| 497 | tg->iops[READ][LIMIT_MAX] = UINT_MAX; |
| 498 | tg->iops[WRITE][LIMIT_MAX] = UINT_MAX; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 499 | tg->bps_conf[READ][LIMIT_MAX] = U64_MAX; |
| 500 | tg->bps_conf[WRITE][LIMIT_MAX] = U64_MAX; |
| 501 | tg->iops_conf[READ][LIMIT_MAX] = UINT_MAX; |
| 502 | tg->iops_conf[WRITE][LIMIT_MAX] = UINT_MAX; |
| 503 | /* LIMIT_LOW will have default value 0 */ |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 504 | |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 505 | tg->latency_target = DFL_LATENCY_TARGET; |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 506 | tg->latency_target_conf = DFL_LATENCY_TARGET; |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 507 | tg->idletime_threshold = DFL_IDLE_THRESHOLD; |
| 508 | tg->idletime_threshold_conf = DFL_IDLE_THRESHOLD; |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 509 | |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 510 | return &tg->pd; |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 511 | } |
| 512 | |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 513 | static void throtl_pd_init(struct blkg_policy_data *pd) |
Vivek Goyal | a29a171 | 2011-05-19 15:38:19 -0400 | [diff] [blame] | 514 | { |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 515 | struct throtl_grp *tg = pd_to_tg(pd); |
| 516 | struct blkcg_gq *blkg = tg_to_blkg(tg); |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 517 | struct throtl_data *td = blkg->q->td; |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 518 | struct throtl_service_queue *sq = &tg->service_queue; |
Tejun Heo | cd1604f | 2012-03-05 13:15:06 -0800 | [diff] [blame] | 519 | |
Tejun Heo | 9138125 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 520 | /* |
Tejun Heo | aa6ec29 | 2014-07-09 10:08:08 -0400 | [diff] [blame] | 521 | * If on the default hierarchy, we switch to properly hierarchical |
Tejun Heo | 9138125 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 522 | * behavior where limits on a given throtl_grp are applied to the |
| 523 | * whole subtree rather than just the group itself. e.g. If 16M |
| 524 | * read_bps limit is set on the root group, the whole system can't |
| 525 | * exceed 16M for the device. |
| 526 | * |
Tejun Heo | aa6ec29 | 2014-07-09 10:08:08 -0400 | [diff] [blame] | 527 | * If not on the default hierarchy, the broken flat hierarchy |
Tejun Heo | 9138125 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 528 | * behavior is retained where all throtl_grps are treated as if |
| 529 | * they're all separate root groups right below throtl_data. |
| 530 | * Limits of a group don't interact with limits of other groups |
| 531 | * regardless of the position of the group in the hierarchy. |
| 532 | */ |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 533 | sq->parent_sq = &td->service_queue; |
Tejun Heo | 9e10a13 | 2015-09-18 11:56:28 -0400 | [diff] [blame] | 534 | if (cgroup_subsys_on_dfl(io_cgrp_subsys) && blkg->parent) |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 535 | sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 536 | tg->td = td; |
Tejun Heo | 8a3d261 | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 537 | } |
| 538 | |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 539 | /* |
| 540 | * Set has_rules[] if @tg or any of its parents have limits configured. |
| 541 | * This doesn't require walking up to the top of the hierarchy as the |
| 542 | * parent's has_rules[] is guaranteed to be correct. |
| 543 | */ |
| 544 | static void tg_update_has_rules(struct throtl_grp *tg) |
| 545 | { |
| 546 | struct throtl_grp *parent_tg = sq_to_tg(tg->service_queue.parent_sq); |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 547 | struct throtl_data *td = tg->td; |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 548 | int rw; |
| 549 | |
| 550 | for (rw = READ; rw <= WRITE; rw++) |
| 551 | tg->has_rules[rw] = (parent_tg && parent_tg->has_rules[rw]) || |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 552 | (td->limit_valid[td->limit_index] && |
| 553 | (tg_bps_limit(tg, rw) != U64_MAX || |
| 554 | tg_iops_limit(tg, rw) != UINT_MAX)); |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 555 | } |
| 556 | |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 557 | static void throtl_pd_online(struct blkg_policy_data *pd) |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 558 | { |
Shaohua Li | aec2424 | 2017-03-27 10:51:39 -0700 | [diff] [blame] | 559 | struct throtl_grp *tg = pd_to_tg(pd); |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 560 | /* |
| 561 | * We don't want new groups to escape the limits of its ancestors. |
| 562 | * Update has_rules[] after a new group is brought online. |
| 563 | */ |
Shaohua Li | aec2424 | 2017-03-27 10:51:39 -0700 | [diff] [blame] | 564 | tg_update_has_rules(tg); |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 565 | } |
| 566 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 567 | static void blk_throtl_update_limit_valid(struct throtl_data *td) |
| 568 | { |
| 569 | struct cgroup_subsys_state *pos_css; |
| 570 | struct blkcg_gq *blkg; |
| 571 | bool low_valid = false; |
| 572 | |
| 573 | rcu_read_lock(); |
| 574 | blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { |
| 575 | struct throtl_grp *tg = blkg_to_tg(blkg); |
| 576 | |
| 577 | if (tg->bps[READ][LIMIT_LOW] || tg->bps[WRITE][LIMIT_LOW] || |
| 578 | tg->iops[READ][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) |
| 579 | low_valid = true; |
| 580 | } |
| 581 | rcu_read_unlock(); |
| 582 | |
| 583 | td->limit_valid[LIMIT_LOW] = low_valid; |
| 584 | } |
| 585 | |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 586 | static void throtl_upgrade_state(struct throtl_data *td); |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 587 | static void throtl_pd_offline(struct blkg_policy_data *pd) |
| 588 | { |
| 589 | struct throtl_grp *tg = pd_to_tg(pd); |
| 590 | |
| 591 | tg->bps[READ][LIMIT_LOW] = 0; |
| 592 | tg->bps[WRITE][LIMIT_LOW] = 0; |
| 593 | tg->iops[READ][LIMIT_LOW] = 0; |
| 594 | tg->iops[WRITE][LIMIT_LOW] = 0; |
| 595 | |
| 596 | blk_throtl_update_limit_valid(tg->td); |
| 597 | |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 598 | if (!tg->td->limit_valid[tg->td->limit_index]) |
| 599 | throtl_upgrade_state(tg->td); |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 600 | } |
| 601 | |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 602 | static void throtl_pd_free(struct blkg_policy_data *pd) |
| 603 | { |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 604 | struct throtl_grp *tg = pd_to_tg(pd); |
| 605 | |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 606 | del_timer_sync(&tg->service_queue.pending_timer); |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 607 | kfree(tg); |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 608 | } |
| 609 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 610 | static struct throtl_grp * |
| 611 | throtl_rb_first(struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 612 | { |
| 613 | /* Service tree is empty */ |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 614 | if (!parent_sq->nr_pending) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 615 | return NULL; |
| 616 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 617 | if (!parent_sq->first_pending) |
| 618 | parent_sq->first_pending = rb_first(&parent_sq->pending_tree); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 619 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 620 | if (parent_sq->first_pending) |
| 621 | return rb_entry_tg(parent_sq->first_pending); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 622 | |
| 623 | return NULL; |
| 624 | } |
| 625 | |
| 626 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 627 | { |
| 628 | rb_erase(n, root); |
| 629 | RB_CLEAR_NODE(n); |
| 630 | } |
| 631 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 632 | static void throtl_rb_erase(struct rb_node *n, |
| 633 | struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 634 | { |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 635 | if (parent_sq->first_pending == n) |
| 636 | parent_sq->first_pending = NULL; |
| 637 | rb_erase_init(n, &parent_sq->pending_tree); |
| 638 | --parent_sq->nr_pending; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 639 | } |
| 640 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 641 | static void update_min_dispatch_time(struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 642 | { |
| 643 | struct throtl_grp *tg; |
| 644 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 645 | tg = throtl_rb_first(parent_sq); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 646 | if (!tg) |
| 647 | return; |
| 648 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 649 | parent_sq->first_pending_disptime = tg->disptime; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 650 | } |
| 651 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 652 | static void tg_service_queue_add(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 653 | { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 654 | struct throtl_service_queue *parent_sq = tg->service_queue.parent_sq; |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 655 | struct rb_node **node = &parent_sq->pending_tree.rb_node; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 656 | struct rb_node *parent = NULL; |
| 657 | struct throtl_grp *__tg; |
| 658 | unsigned long key = tg->disptime; |
| 659 | int left = 1; |
| 660 | |
| 661 | while (*node != NULL) { |
| 662 | parent = *node; |
| 663 | __tg = rb_entry_tg(parent); |
| 664 | |
| 665 | if (time_before(key, __tg->disptime)) |
| 666 | node = &parent->rb_left; |
| 667 | else { |
| 668 | node = &parent->rb_right; |
| 669 | left = 0; |
| 670 | } |
| 671 | } |
| 672 | |
| 673 | if (left) |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 674 | parent_sq->first_pending = &tg->rb_node; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 675 | |
| 676 | rb_link_node(&tg->rb_node, parent, node); |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 677 | rb_insert_color(&tg->rb_node, &parent_sq->pending_tree); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 678 | } |
| 679 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 680 | static void __throtl_enqueue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 681 | { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 682 | tg_service_queue_add(tg); |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 683 | tg->flags |= THROTL_TG_PENDING; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 684 | tg->service_queue.parent_sq->nr_pending++; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 685 | } |
| 686 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 687 | static void throtl_enqueue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 688 | { |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 689 | if (!(tg->flags & THROTL_TG_PENDING)) |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 690 | __throtl_enqueue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 691 | } |
| 692 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 693 | static void __throtl_dequeue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 694 | { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 695 | throtl_rb_erase(&tg->rb_node, tg->service_queue.parent_sq); |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 696 | tg->flags &= ~THROTL_TG_PENDING; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 697 | } |
| 698 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 699 | static void throtl_dequeue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 700 | { |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 701 | if (tg->flags & THROTL_TG_PENDING) |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 702 | __throtl_dequeue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 703 | } |
| 704 | |
Tejun Heo | a9131a2 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 705 | /* Call with queue lock held */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 706 | static void throtl_schedule_pending_timer(struct throtl_service_queue *sq, |
| 707 | unsigned long expires) |
Tejun Heo | a9131a2 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 708 | { |
Joseph Qi | a41b816 | 2017-06-07 11:36:14 +0800 | [diff] [blame] | 709 | unsigned long max_expire = jiffies + 8 * sq_to_td(sq)->throtl_slice; |
Shaohua Li | 06cceed | 2017-03-27 10:51:36 -0700 | [diff] [blame] | 710 | |
| 711 | /* |
| 712 | * Since we are adjusting the throttle limit dynamically, the sleep |
| 713 | * time calculated according to previous limit might be invalid. It's |
| 714 | * possible the cgroup sleep time is very long and no other cgroups |
| 715 | * have IO running so notify the limit changes. Make sure the cgroup |
| 716 | * doesn't sleep too long to avoid the missed notification. |
| 717 | */ |
| 718 | if (time_after(expires, max_expire)) |
| 719 | expires = max_expire; |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 720 | mod_timer(&sq->pending_timer, expires); |
| 721 | throtl_log(sq, "schedule timer. delay=%lu jiffies=%lu", |
| 722 | expires - jiffies, jiffies); |
Tejun Heo | a9131a2 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 723 | } |
| 724 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 725 | /** |
| 726 | * throtl_schedule_next_dispatch - schedule the next dispatch cycle |
| 727 | * @sq: the service_queue to schedule dispatch for |
| 728 | * @force: force scheduling |
| 729 | * |
| 730 | * Arm @sq->pending_timer so that the next dispatch cycle starts on the |
| 731 | * dispatch time of the first pending child. Returns %true if either timer |
| 732 | * is armed or there's no pending child left. %false if the current |
| 733 | * dispatch window is still open and the caller should continue |
| 734 | * dispatching. |
| 735 | * |
| 736 | * If @force is %true, the dispatch timer is always scheduled and this |
| 737 | * function is guaranteed to return %true. This is to be used when the |
| 738 | * caller can't dispatch itself and needs to invoke pending_timer |
| 739 | * unconditionally. Note that forced scheduling is likely to induce short |
| 740 | * delay before dispatch starts even if @sq->first_pending_disptime is not |
| 741 | * in the future and thus shouldn't be used in hot paths. |
| 742 | */ |
| 743 | static bool throtl_schedule_next_dispatch(struct throtl_service_queue *sq, |
| 744 | bool force) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 745 | { |
Tejun Heo | 6a52560 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 746 | /* any pending children left? */ |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 747 | if (!sq->nr_pending) |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 748 | return true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 749 | |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 750 | update_min_dispatch_time(sq); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 751 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 752 | /* is the next dispatch time in the future? */ |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 753 | if (force || time_after(sq->first_pending_disptime, jiffies)) { |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 754 | throtl_schedule_pending_timer(sq, sq->first_pending_disptime); |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 755 | return true; |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 756 | } |
| 757 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 758 | /* tell the caller to continue dispatching */ |
| 759 | return false; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 760 | } |
| 761 | |
Vivek Goyal | 32ee5bc | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 762 | static inline void throtl_start_new_slice_with_credit(struct throtl_grp *tg, |
| 763 | bool rw, unsigned long start) |
| 764 | { |
| 765 | tg->bytes_disp[rw] = 0; |
| 766 | tg->io_disp[rw] = 0; |
| 767 | |
| 768 | /* |
| 769 | * Previous slice has expired. We must have trimmed it after last |
| 770 | * bio dispatch. That means since start of last slice, we never used |
| 771 | * that bandwidth. Do try to make use of that bandwidth while giving |
| 772 | * credit. |
| 773 | */ |
| 774 | if (time_after_eq(start, tg->slice_start[rw])) |
| 775 | tg->slice_start[rw] = start; |
| 776 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 777 | tg->slice_end[rw] = jiffies + tg->td->throtl_slice; |
Vivek Goyal | 32ee5bc | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 778 | throtl_log(&tg->service_queue, |
| 779 | "[%c] new slice with credit start=%lu end=%lu jiffies=%lu", |
| 780 | rw == READ ? 'R' : 'W', tg->slice_start[rw], |
| 781 | tg->slice_end[rw], jiffies); |
| 782 | } |
| 783 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 784 | static inline void throtl_start_new_slice(struct throtl_grp *tg, bool rw) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 785 | { |
| 786 | tg->bytes_disp[rw] = 0; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 787 | tg->io_disp[rw] = 0; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 788 | tg->slice_start[rw] = jiffies; |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 789 | tg->slice_end[rw] = jiffies + tg->td->throtl_slice; |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 790 | throtl_log(&tg->service_queue, |
| 791 | "[%c] new slice start=%lu end=%lu jiffies=%lu", |
| 792 | rw == READ ? 'R' : 'W', tg->slice_start[rw], |
| 793 | tg->slice_end[rw], jiffies); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 794 | } |
| 795 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 796 | static inline void throtl_set_slice_end(struct throtl_grp *tg, bool rw, |
| 797 | unsigned long jiffy_end) |
Vivek Goyal | d1ae8ff | 2010-12-01 19:34:46 +0100 | [diff] [blame] | 798 | { |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 799 | tg->slice_end[rw] = roundup(jiffy_end, tg->td->throtl_slice); |
Vivek Goyal | d1ae8ff | 2010-12-01 19:34:46 +0100 | [diff] [blame] | 800 | } |
| 801 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 802 | static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw, |
| 803 | unsigned long jiffy_end) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 804 | { |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 805 | tg->slice_end[rw] = roundup(jiffy_end, tg->td->throtl_slice); |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 806 | throtl_log(&tg->service_queue, |
| 807 | "[%c] extend slice start=%lu end=%lu jiffies=%lu", |
| 808 | rw == READ ? 'R' : 'W', tg->slice_start[rw], |
| 809 | tg->slice_end[rw], jiffies); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 810 | } |
| 811 | |
| 812 | /* Determine if previously allocated or extended slice is complete or not */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 813 | static bool throtl_slice_used(struct throtl_grp *tg, bool rw) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 814 | { |
| 815 | if (time_in_range(jiffies, tg->slice_start[rw], tg->slice_end[rw])) |
Fabian Frederick | 5cf8c22 | 2014-05-02 18:28:17 +0200 | [diff] [blame] | 816 | return false; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 817 | |
| 818 | return 1; |
| 819 | } |
| 820 | |
| 821 | /* Trim the used slices and adjust slice start accordingly */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 822 | static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 823 | { |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 824 | unsigned long nr_slices, time_elapsed, io_trim; |
| 825 | u64 bytes_trim, tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 826 | |
| 827 | BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw])); |
| 828 | |
| 829 | /* |
| 830 | * If bps are unlimited (-1), then time slice don't get |
| 831 | * renewed. Don't try to trim the slice if slice is used. A new |
| 832 | * slice will start when appropriate. |
| 833 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 834 | if (throtl_slice_used(tg, rw)) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 835 | return; |
| 836 | |
Vivek Goyal | d1ae8ff | 2010-12-01 19:34:46 +0100 | [diff] [blame] | 837 | /* |
| 838 | * A bio has been dispatched. Also adjust slice_end. It might happen |
| 839 | * that initially cgroup limit was very low resulting in high |
| 840 | * slice_end, but later limit was bumped up and bio was dispached |
| 841 | * sooner, then we need to reduce slice_end. A high bogus slice_end |
| 842 | * is bad because it does not allow new slice to start. |
| 843 | */ |
| 844 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 845 | throtl_set_slice_end(tg, rw, jiffies + tg->td->throtl_slice); |
Vivek Goyal | d1ae8ff | 2010-12-01 19:34:46 +0100 | [diff] [blame] | 846 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 847 | time_elapsed = jiffies - tg->slice_start[rw]; |
| 848 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 849 | nr_slices = time_elapsed / tg->td->throtl_slice; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 850 | |
| 851 | if (!nr_slices) |
| 852 | return; |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 853 | tmp = tg_bps_limit(tg, rw) * tg->td->throtl_slice * nr_slices; |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 854 | do_div(tmp, HZ); |
| 855 | bytes_trim = tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 856 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 857 | io_trim = (tg_iops_limit(tg, rw) * tg->td->throtl_slice * nr_slices) / |
| 858 | HZ; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 859 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 860 | if (!bytes_trim && !io_trim) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 861 | return; |
| 862 | |
| 863 | if (tg->bytes_disp[rw] >= bytes_trim) |
| 864 | tg->bytes_disp[rw] -= bytes_trim; |
| 865 | else |
| 866 | tg->bytes_disp[rw] = 0; |
| 867 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 868 | if (tg->io_disp[rw] >= io_trim) |
| 869 | tg->io_disp[rw] -= io_trim; |
| 870 | else |
| 871 | tg->io_disp[rw] = 0; |
| 872 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 873 | tg->slice_start[rw] += nr_slices * tg->td->throtl_slice; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 874 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 875 | throtl_log(&tg->service_queue, |
| 876 | "[%c] trim slice nr=%lu bytes=%llu io=%lu start=%lu end=%lu jiffies=%lu", |
| 877 | rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim, |
| 878 | tg->slice_start[rw], tg->slice_end[rw], jiffies); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 879 | } |
| 880 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 881 | static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, |
| 882 | unsigned long *wait) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 883 | { |
| 884 | bool rw = bio_data_dir(bio); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 885 | unsigned int io_allowed; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 886 | unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; |
Vivek Goyal | c49c06e | 2010-10-01 21:16:42 +0200 | [diff] [blame] | 887 | u64 tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 888 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 889 | jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw]; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 890 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 891 | /* Slice has just started. Consider one slice interval */ |
| 892 | if (!jiffy_elapsed) |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 893 | jiffy_elapsed_rnd = tg->td->throtl_slice; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 894 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 895 | jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, tg->td->throtl_slice); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 896 | |
Vivek Goyal | c49c06e | 2010-10-01 21:16:42 +0200 | [diff] [blame] | 897 | /* |
| 898 | * jiffy_elapsed_rnd should not be a big value as minimum iops can be |
| 899 | * 1 then at max jiffy elapsed should be equivalent of 1 second as we |
| 900 | * will allow dispatch after 1 second and after that slice should |
| 901 | * have been trimmed. |
| 902 | */ |
| 903 | |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 904 | tmp = (u64)tg_iops_limit(tg, rw) * jiffy_elapsed_rnd; |
Vivek Goyal | c49c06e | 2010-10-01 21:16:42 +0200 | [diff] [blame] | 905 | do_div(tmp, HZ); |
| 906 | |
| 907 | if (tmp > UINT_MAX) |
| 908 | io_allowed = UINT_MAX; |
| 909 | else |
| 910 | io_allowed = tmp; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 911 | |
| 912 | if (tg->io_disp[rw] + 1 <= io_allowed) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 913 | if (wait) |
| 914 | *wait = 0; |
Fabian Frederick | 5cf8c22 | 2014-05-02 18:28:17 +0200 | [diff] [blame] | 915 | return true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 916 | } |
| 917 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 918 | /* Calc approx time to dispatch */ |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 919 | jiffy_wait = ((tg->io_disp[rw] + 1) * HZ) / tg_iops_limit(tg, rw) + 1; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 920 | |
| 921 | if (jiffy_wait > jiffy_elapsed) |
| 922 | jiffy_wait = jiffy_wait - jiffy_elapsed; |
| 923 | else |
| 924 | jiffy_wait = 1; |
| 925 | |
| 926 | if (wait) |
| 927 | *wait = jiffy_wait; |
| 928 | return 0; |
| 929 | } |
| 930 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 931 | static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, |
| 932 | unsigned long *wait) |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 933 | { |
| 934 | bool rw = bio_data_dir(bio); |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 935 | u64 bytes_allowed, extra_bytes, tmp; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 936 | unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 937 | |
| 938 | jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw]; |
| 939 | |
| 940 | /* Slice has just started. Consider one slice interval */ |
| 941 | if (!jiffy_elapsed) |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 942 | jiffy_elapsed_rnd = tg->td->throtl_slice; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 943 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 944 | jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, tg->td->throtl_slice); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 945 | |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 946 | tmp = tg_bps_limit(tg, rw) * jiffy_elapsed_rnd; |
Vivek Goyal | 5e901a2 | 2010-10-01 21:16:38 +0200 | [diff] [blame] | 947 | do_div(tmp, HZ); |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 948 | bytes_allowed = tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 949 | |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 950 | if (tg->bytes_disp[rw] + bio->bi_iter.bi_size <= bytes_allowed) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 951 | if (wait) |
| 952 | *wait = 0; |
Fabian Frederick | 5cf8c22 | 2014-05-02 18:28:17 +0200 | [diff] [blame] | 953 | return true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 954 | } |
| 955 | |
| 956 | /* Calc approx time to dispatch */ |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 957 | extra_bytes = tg->bytes_disp[rw] + bio->bi_iter.bi_size - bytes_allowed; |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 958 | jiffy_wait = div64_u64(extra_bytes * HZ, tg_bps_limit(tg, rw)); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 959 | |
| 960 | if (!jiffy_wait) |
| 961 | jiffy_wait = 1; |
| 962 | |
| 963 | /* |
| 964 | * This wait time is without taking into consideration the rounding |
| 965 | * up we did. Add that time also. |
| 966 | */ |
| 967 | jiffy_wait = jiffy_wait + (jiffy_elapsed_rnd - jiffy_elapsed); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 968 | if (wait) |
| 969 | *wait = jiffy_wait; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 970 | return 0; |
| 971 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 972 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 973 | /* |
| 974 | * Returns whether one can dispatch a bio or not. Also returns approx number |
| 975 | * of jiffies to wait before this bio is with-in IO rate and can be dispatched |
| 976 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 977 | static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, |
| 978 | unsigned long *wait) |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 979 | { |
| 980 | bool rw = bio_data_dir(bio); |
| 981 | unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0; |
| 982 | |
| 983 | /* |
| 984 | * Currently whole state machine of group depends on first bio |
| 985 | * queued in the group bio list. So one should not be calling |
| 986 | * this function with a different bio if there are other bios |
| 987 | * queued. |
| 988 | */ |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 989 | BUG_ON(tg->service_queue.nr_queued[rw] && |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 990 | bio != throtl_peek_queued(&tg->service_queue.queued[rw])); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 991 | |
| 992 | /* If tg->bps = -1, then BW is unlimited */ |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 993 | if (tg_bps_limit(tg, rw) == U64_MAX && |
| 994 | tg_iops_limit(tg, rw) == UINT_MAX) { |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 995 | if (wait) |
| 996 | *wait = 0; |
Fabian Frederick | 5cf8c22 | 2014-05-02 18:28:17 +0200 | [diff] [blame] | 997 | return true; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 998 | } |
| 999 | |
| 1000 | /* |
| 1001 | * If previous slice expired, start a new one otherwise renew/extend |
| 1002 | * existing slice to make sure it is at least throtl_slice interval |
Vivek Goyal | 164c80e | 2016-09-19 15:12:41 -0600 | [diff] [blame] | 1003 | * long since now. New slice is started only for empty throttle group. |
| 1004 | * If there is queued bio, that means there should be an active |
| 1005 | * slice and it should be extended instead. |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 1006 | */ |
Vivek Goyal | 164c80e | 2016-09-19 15:12:41 -0600 | [diff] [blame] | 1007 | if (throtl_slice_used(tg, rw) && !(tg->service_queue.nr_queued[rw])) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1008 | throtl_start_new_slice(tg, rw); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 1009 | else { |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 1010 | if (time_before(tg->slice_end[rw], |
| 1011 | jiffies + tg->td->throtl_slice)) |
| 1012 | throtl_extend_slice(tg, rw, |
| 1013 | jiffies + tg->td->throtl_slice); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 1014 | } |
| 1015 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1016 | if (tg_with_in_bps_limit(tg, bio, &bps_wait) && |
| 1017 | tg_with_in_iops_limit(tg, bio, &iops_wait)) { |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 1018 | if (wait) |
| 1019 | *wait = 0; |
| 1020 | return 1; |
| 1021 | } |
| 1022 | |
| 1023 | max_wait = max(bps_wait, iops_wait); |
| 1024 | |
| 1025 | if (wait) |
| 1026 | *wait = max_wait; |
| 1027 | |
| 1028 | if (time_before(tg->slice_end[rw], jiffies + max_wait)) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1029 | throtl_extend_slice(tg, rw, jiffies + max_wait); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1030 | |
| 1031 | return 0; |
| 1032 | } |
| 1033 | |
| 1034 | static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio) |
| 1035 | { |
| 1036 | bool rw = bio_data_dir(bio); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1037 | |
| 1038 | /* Charge the bio to the group */ |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 1039 | tg->bytes_disp[rw] += bio->bi_iter.bi_size; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 1040 | tg->io_disp[rw]++; |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1041 | tg->last_bytes_disp[rw] += bio->bi_iter.bi_size; |
| 1042 | tg->last_io_disp[rw]++; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1043 | |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1044 | /* |
Christoph Hellwig | 8d2bbd4 | 2016-10-20 15:12:12 +0200 | [diff] [blame] | 1045 | * BIO_THROTTLED is used to prevent the same bio to be throttled |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1046 | * more than once as a throttled bio will go through blk-throtl the |
| 1047 | * second time when it eventually gets issued. Set it when a bio |
| 1048 | * is being charged to a tg. |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1049 | */ |
Christoph Hellwig | 8d2bbd4 | 2016-10-20 15:12:12 +0200 | [diff] [blame] | 1050 | if (!bio_flagged(bio, BIO_THROTTLED)) |
| 1051 | bio_set_flag(bio, BIO_THROTTLED); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1052 | } |
| 1053 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1054 | /** |
| 1055 | * throtl_add_bio_tg - add a bio to the specified throtl_grp |
| 1056 | * @bio: bio to add |
| 1057 | * @qn: qnode to use |
| 1058 | * @tg: the target throtl_grp |
| 1059 | * |
| 1060 | * Add @bio to @tg's service_queue using @qn. If @qn is not specified, |
| 1061 | * tg->qnode_on_self[] is used. |
| 1062 | */ |
| 1063 | static void throtl_add_bio_tg(struct bio *bio, struct throtl_qnode *qn, |
| 1064 | struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1065 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1066 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1067 | bool rw = bio_data_dir(bio); |
| 1068 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1069 | if (!qn) |
| 1070 | qn = &tg->qnode_on_self[rw]; |
| 1071 | |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1072 | /* |
| 1073 | * If @tg doesn't currently have any bios queued in the same |
| 1074 | * direction, queueing @bio can change when @tg should be |
| 1075 | * dispatched. Mark that @tg was empty. This is automatically |
| 1076 | * cleaered on the next tg_update_disptime(). |
| 1077 | */ |
| 1078 | if (!sq->nr_queued[rw]) |
| 1079 | tg->flags |= THROTL_TG_WAS_EMPTY; |
| 1080 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1081 | throtl_qnode_add_bio(bio, qn, &sq->queued[rw]); |
| 1082 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1083 | sq->nr_queued[rw]++; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1084 | throtl_enqueue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1085 | } |
| 1086 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1087 | static void tg_update_disptime(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1088 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1089 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1090 | unsigned long read_wait = -1, write_wait = -1, min_wait = -1, disptime; |
| 1091 | struct bio *bio; |
| 1092 | |
Markus Elfring | d609af3 | 2017-01-21 22:15:33 +0100 | [diff] [blame] | 1093 | bio = throtl_peek_queued(&sq->queued[READ]); |
| 1094 | if (bio) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1095 | tg_may_dispatch(tg, bio, &read_wait); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1096 | |
Markus Elfring | d609af3 | 2017-01-21 22:15:33 +0100 | [diff] [blame] | 1097 | bio = throtl_peek_queued(&sq->queued[WRITE]); |
| 1098 | if (bio) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1099 | tg_may_dispatch(tg, bio, &write_wait); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1100 | |
| 1101 | min_wait = min(read_wait, write_wait); |
| 1102 | disptime = jiffies + min_wait; |
| 1103 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1104 | /* Update dispatch time */ |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1105 | throtl_dequeue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1106 | tg->disptime = disptime; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1107 | throtl_enqueue_tg(tg); |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1108 | |
| 1109 | /* see throtl_add_bio_tg() */ |
| 1110 | tg->flags &= ~THROTL_TG_WAS_EMPTY; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1111 | } |
| 1112 | |
Vivek Goyal | 32ee5bc | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1113 | static void start_parent_slice_with_credit(struct throtl_grp *child_tg, |
| 1114 | struct throtl_grp *parent_tg, bool rw) |
| 1115 | { |
| 1116 | if (throtl_slice_used(parent_tg, rw)) { |
| 1117 | throtl_start_new_slice_with_credit(parent_tg, rw, |
| 1118 | child_tg->slice_start[rw]); |
| 1119 | } |
| 1120 | |
| 1121 | } |
| 1122 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1123 | static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1124 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1125 | struct throtl_service_queue *sq = &tg->service_queue; |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1126 | struct throtl_service_queue *parent_sq = sq->parent_sq; |
| 1127 | struct throtl_grp *parent_tg = sq_to_tg(parent_sq); |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1128 | struct throtl_grp *tg_to_put = NULL; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1129 | struct bio *bio; |
| 1130 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1131 | /* |
| 1132 | * @bio is being transferred from @tg to @parent_sq. Popping a bio |
| 1133 | * from @tg may put its reference and @parent_sq might end up |
| 1134 | * getting released prematurely. Remember the tg to put and put it |
| 1135 | * after @bio is transferred to @parent_sq. |
| 1136 | */ |
| 1137 | bio = throtl_pop_queued(&sq->queued[rw], &tg_to_put); |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1138 | sq->nr_queued[rw]--; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1139 | |
| 1140 | throtl_charge_bio(tg, bio); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1141 | |
| 1142 | /* |
| 1143 | * If our parent is another tg, we just need to transfer @bio to |
| 1144 | * the parent using throtl_add_bio_tg(). If our parent is |
| 1145 | * @td->service_queue, @bio is ready to be issued. Put it on its |
| 1146 | * bio_lists[] and decrease total number queued. The caller is |
| 1147 | * responsible for issuing these bios. |
| 1148 | */ |
| 1149 | if (parent_tg) { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1150 | throtl_add_bio_tg(bio, &tg->qnode_on_parent[rw], parent_tg); |
Vivek Goyal | 32ee5bc | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1151 | start_parent_slice_with_credit(tg, parent_tg, rw); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1152 | } else { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1153 | throtl_qnode_add_bio(bio, &tg->qnode_on_parent[rw], |
| 1154 | &parent_sq->queued[rw]); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1155 | BUG_ON(tg->td->nr_queued[rw] <= 0); |
| 1156 | tg->td->nr_queued[rw]--; |
| 1157 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1158 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1159 | throtl_trim_slice(tg, rw); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1160 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1161 | if (tg_to_put) |
| 1162 | blkg_put(tg_to_blkg(tg_to_put)); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1163 | } |
| 1164 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1165 | static int throtl_dispatch_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1166 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1167 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1168 | unsigned int nr_reads = 0, nr_writes = 0; |
| 1169 | unsigned int max_nr_reads = throtl_grp_quantum*3/4; |
Vivek Goyal | c2f6805 | 2010-11-15 19:32:42 +0100 | [diff] [blame] | 1170 | unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1171 | struct bio *bio; |
| 1172 | |
| 1173 | /* Try to dispatch 75% READS and 25% WRITES */ |
| 1174 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1175 | while ((bio = throtl_peek_queued(&sq->queued[READ])) && |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1176 | tg_may_dispatch(tg, bio, NULL)) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1177 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1178 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1179 | nr_reads++; |
| 1180 | |
| 1181 | if (nr_reads >= max_nr_reads) |
| 1182 | break; |
| 1183 | } |
| 1184 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1185 | while ((bio = throtl_peek_queued(&sq->queued[WRITE])) && |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1186 | tg_may_dispatch(tg, bio, NULL)) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1187 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1188 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1189 | nr_writes++; |
| 1190 | |
| 1191 | if (nr_writes >= max_nr_writes) |
| 1192 | break; |
| 1193 | } |
| 1194 | |
| 1195 | return nr_reads + nr_writes; |
| 1196 | } |
| 1197 | |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1198 | static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1199 | { |
| 1200 | unsigned int nr_disp = 0; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1201 | |
| 1202 | while (1) { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1203 | struct throtl_grp *tg = throtl_rb_first(parent_sq); |
| 1204 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1205 | |
| 1206 | if (!tg) |
| 1207 | break; |
| 1208 | |
| 1209 | if (time_before(jiffies, tg->disptime)) |
| 1210 | break; |
| 1211 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1212 | throtl_dequeue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1213 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1214 | nr_disp += throtl_dispatch_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1215 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1216 | if (sq->nr_queued[0] || sq->nr_queued[1]) |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1217 | tg_update_disptime(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1218 | |
| 1219 | if (nr_disp >= throtl_quantum) |
| 1220 | break; |
| 1221 | } |
| 1222 | |
| 1223 | return nr_disp; |
| 1224 | } |
| 1225 | |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1226 | static bool throtl_can_upgrade(struct throtl_data *td, |
| 1227 | struct throtl_grp *this_tg); |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1228 | /** |
| 1229 | * throtl_pending_timer_fn - timer function for service_queue->pending_timer |
| 1230 | * @arg: the throtl_service_queue being serviced |
| 1231 | * |
| 1232 | * This timer is armed when a child throtl_grp with active bio's become |
| 1233 | * pending and queued on the service_queue's pending_tree and expires when |
| 1234 | * the first child throtl_grp should be dispatched. This function |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1235 | * dispatches bio's from the children throtl_grps to the parent |
| 1236 | * service_queue. |
| 1237 | * |
| 1238 | * If the parent's parent is another throtl_grp, dispatching is propagated |
| 1239 | * by either arming its pending_timer or repeating dispatch directly. If |
| 1240 | * the top-level service_tree is reached, throtl_data->dispatch_work is |
| 1241 | * kicked so that the ready bio's are issued. |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1242 | */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1243 | static void throtl_pending_timer_fn(unsigned long arg) |
| 1244 | { |
| 1245 | struct throtl_service_queue *sq = (void *)arg; |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1246 | struct throtl_grp *tg = sq_to_tg(sq); |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1247 | struct throtl_data *td = sq_to_td(sq); |
Tejun Heo | cb76199 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1248 | struct request_queue *q = td->queue; |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1249 | struct throtl_service_queue *parent_sq; |
| 1250 | bool dispatched; |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1251 | int ret; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1252 | |
| 1253 | spin_lock_irq(q->queue_lock); |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1254 | if (throtl_can_upgrade(td, NULL)) |
| 1255 | throtl_upgrade_state(td); |
| 1256 | |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1257 | again: |
| 1258 | parent_sq = sq->parent_sq; |
| 1259 | dispatched = false; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1260 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1261 | while (true) { |
| 1262 | throtl_log(sq, "dispatch nr_queued=%u read=%u write=%u", |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1263 | sq->nr_queued[READ] + sq->nr_queued[WRITE], |
| 1264 | sq->nr_queued[READ], sq->nr_queued[WRITE]); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1265 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1266 | ret = throtl_select_dispatch(sq); |
| 1267 | if (ret) { |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1268 | throtl_log(sq, "bios disp=%u", ret); |
| 1269 | dispatched = true; |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1270 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1271 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1272 | if (throtl_schedule_next_dispatch(sq, false)) |
| 1273 | break; |
| 1274 | |
| 1275 | /* this dispatch windows is still open, relax and repeat */ |
| 1276 | spin_unlock_irq(q->queue_lock); |
| 1277 | cpu_relax(); |
| 1278 | spin_lock_irq(q->queue_lock); |
| 1279 | } |
Tejun Heo | 6a52560 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1280 | |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1281 | if (!dispatched) |
| 1282 | goto out_unlock; |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1283 | |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1284 | if (parent_sq) { |
| 1285 | /* @parent_sq is another throl_grp, propagate dispatch */ |
| 1286 | if (tg->flags & THROTL_TG_WAS_EMPTY) { |
| 1287 | tg_update_disptime(tg); |
| 1288 | if (!throtl_schedule_next_dispatch(parent_sq, false)) { |
| 1289 | /* window is already open, repeat dispatching */ |
| 1290 | sq = parent_sq; |
| 1291 | tg = sq_to_tg(sq); |
| 1292 | goto again; |
| 1293 | } |
| 1294 | } |
| 1295 | } else { |
| 1296 | /* reached the top-level, queue issueing */ |
| 1297 | queue_work(kthrotld_workqueue, &td->dispatch_work); |
| 1298 | } |
| 1299 | out_unlock: |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1300 | spin_unlock_irq(q->queue_lock); |
| 1301 | } |
| 1302 | |
| 1303 | /** |
| 1304 | * blk_throtl_dispatch_work_fn - work function for throtl_data->dispatch_work |
| 1305 | * @work: work item being executed |
| 1306 | * |
| 1307 | * This function is queued for execution when bio's reach the bio_lists[] |
| 1308 | * of throtl_data->service_queue. Those bio's are ready and issued by this |
| 1309 | * function. |
| 1310 | */ |
Fabian Frederick | 8876e14 | 2014-04-17 21:41:16 +0200 | [diff] [blame] | 1311 | static void blk_throtl_dispatch_work_fn(struct work_struct *work) |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1312 | { |
| 1313 | struct throtl_data *td = container_of(work, struct throtl_data, |
| 1314 | dispatch_work); |
| 1315 | struct throtl_service_queue *td_sq = &td->service_queue; |
| 1316 | struct request_queue *q = td->queue; |
| 1317 | struct bio_list bio_list_on_stack; |
| 1318 | struct bio *bio; |
| 1319 | struct blk_plug plug; |
| 1320 | int rw; |
| 1321 | |
| 1322 | bio_list_init(&bio_list_on_stack); |
| 1323 | |
| 1324 | spin_lock_irq(q->queue_lock); |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1325 | for (rw = READ; rw <= WRITE; rw++) |
| 1326 | while ((bio = throtl_pop_queued(&td_sq->queued[rw], NULL))) |
| 1327 | bio_list_add(&bio_list_on_stack, bio); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1328 | spin_unlock_irq(q->queue_lock); |
| 1329 | |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1330 | if (!bio_list_empty(&bio_list_on_stack)) { |
Vivek Goyal | 69d60eb | 2011-03-09 08:27:37 +0100 | [diff] [blame] | 1331 | blk_start_plug(&plug); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1332 | while((bio = bio_list_pop(&bio_list_on_stack))) |
| 1333 | generic_make_request(bio); |
Vivek Goyal | 69d60eb | 2011-03-09 08:27:37 +0100 | [diff] [blame] | 1334 | blk_finish_plug(&plug); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1335 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1336 | } |
| 1337 | |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1338 | static u64 tg_prfill_conf_u64(struct seq_file *sf, struct blkg_policy_data *pd, |
| 1339 | int off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1340 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1341 | struct throtl_grp *tg = pd_to_tg(pd); |
| 1342 | u64 v = *(u64 *)((void *)tg + off); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1343 | |
Shaohua Li | 2ab5492 | 2017-03-27 10:51:29 -0700 | [diff] [blame] | 1344 | if (v == U64_MAX) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1345 | return 0; |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1346 | return __blkg_prfill_u64(sf, pd, v); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1347 | } |
| 1348 | |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1349 | static u64 tg_prfill_conf_uint(struct seq_file *sf, struct blkg_policy_data *pd, |
| 1350 | int off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1351 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1352 | struct throtl_grp *tg = pd_to_tg(pd); |
| 1353 | unsigned int v = *(unsigned int *)((void *)tg + off); |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1354 | |
Shaohua Li | 2ab5492 | 2017-03-27 10:51:29 -0700 | [diff] [blame] | 1355 | if (v == UINT_MAX) |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1356 | return 0; |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1357 | return __blkg_prfill_u64(sf, pd, v); |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1358 | } |
| 1359 | |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1360 | static int tg_print_conf_u64(struct seq_file *sf, void *v) |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1361 | { |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1362 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_u64, |
| 1363 | &blkcg_policy_throtl, seq_cft(sf)->private, false); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1364 | return 0; |
| 1365 | } |
| 1366 | |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1367 | static int tg_print_conf_uint(struct seq_file *sf, void *v) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1368 | { |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1369 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_uint, |
| 1370 | &blkcg_policy_throtl, seq_cft(sf)->private, false); |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1371 | return 0; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1372 | } |
| 1373 | |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1374 | static void tg_conf_updated(struct throtl_grp *tg, bool global) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1375 | { |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1376 | struct throtl_service_queue *sq = &tg->service_queue; |
Tejun Heo | 492eb21 | 2013-08-08 20:11:25 -0400 | [diff] [blame] | 1377 | struct cgroup_subsys_state *pos_css; |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1378 | struct blkcg_gq *blkg; |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1379 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1380 | throtl_log(&tg->service_queue, |
| 1381 | "limit change rbps=%llu wbps=%llu riops=%u wiops=%u", |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1382 | tg_bps_limit(tg, READ), tg_bps_limit(tg, WRITE), |
| 1383 | tg_iops_limit(tg, READ), tg_iops_limit(tg, WRITE)); |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1384 | |
| 1385 | /* |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1386 | * Update has_rules[] flags for the updated tg's subtree. A tg is |
| 1387 | * considered to have rules if either the tg itself or any of its |
| 1388 | * ancestors has rules. This identifies groups without any |
| 1389 | * restrictions in the whole hierarchy and allows them to bypass |
| 1390 | * blk-throttle. |
| 1391 | */ |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1392 | blkg_for_each_descendant_pre(blkg, pos_css, |
| 1393 | global ? tg->td->queue->root_blkg : tg_to_blkg(tg)) { |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1394 | struct throtl_grp *this_tg = blkg_to_tg(blkg); |
| 1395 | struct throtl_grp *parent_tg; |
| 1396 | |
| 1397 | tg_update_has_rules(this_tg); |
| 1398 | /* ignore root/second level */ |
| 1399 | if (!cgroup_subsys_on_dfl(io_cgrp_subsys) || !blkg->parent || |
| 1400 | !blkg->parent->parent) |
| 1401 | continue; |
| 1402 | parent_tg = blkg_to_tg(blkg->parent); |
| 1403 | /* |
| 1404 | * make sure all children has lower idle time threshold and |
| 1405 | * higher latency target |
| 1406 | */ |
| 1407 | this_tg->idletime_threshold = min(this_tg->idletime_threshold, |
| 1408 | parent_tg->idletime_threshold); |
| 1409 | this_tg->latency_target = max(this_tg->latency_target, |
| 1410 | parent_tg->latency_target); |
| 1411 | } |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1412 | |
| 1413 | /* |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1414 | * We're already holding queue_lock and know @tg is valid. Let's |
| 1415 | * apply the new config directly. |
| 1416 | * |
| 1417 | * Restart the slices for both READ and WRITES. It might happen |
| 1418 | * that a group's limit are dropped suddenly and we don't want to |
| 1419 | * account recently dispatched IO with new low rate. |
| 1420 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1421 | throtl_start_new_slice(tg, 0); |
| 1422 | throtl_start_new_slice(tg, 1); |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1423 | |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1424 | if (tg->flags & THROTL_TG_PENDING) { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1425 | tg_update_disptime(tg); |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1426 | throtl_schedule_next_dispatch(sq->parent_sq, true); |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1427 | } |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1428 | } |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1429 | |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1430 | static ssize_t tg_set_conf(struct kernfs_open_file *of, |
| 1431 | char *buf, size_t nbytes, loff_t off, bool is_u64) |
| 1432 | { |
| 1433 | struct blkcg *blkcg = css_to_blkcg(of_css(of)); |
| 1434 | struct blkg_conf_ctx ctx; |
| 1435 | struct throtl_grp *tg; |
| 1436 | int ret; |
| 1437 | u64 v; |
| 1438 | |
| 1439 | ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx); |
| 1440 | if (ret) |
| 1441 | return ret; |
| 1442 | |
| 1443 | ret = -EINVAL; |
| 1444 | if (sscanf(ctx.body, "%llu", &v) != 1) |
| 1445 | goto out_finish; |
| 1446 | if (!v) |
Shaohua Li | 2ab5492 | 2017-03-27 10:51:29 -0700 | [diff] [blame] | 1447 | v = U64_MAX; |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1448 | |
| 1449 | tg = blkg_to_tg(ctx.blkg); |
| 1450 | |
| 1451 | if (is_u64) |
| 1452 | *(u64 *)((void *)tg + of_cft(of)->private) = v; |
| 1453 | else |
| 1454 | *(unsigned int *)((void *)tg + of_cft(of)->private) = v; |
| 1455 | |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1456 | tg_conf_updated(tg, false); |
Tejun Heo | 36aa9e5 | 2015-08-18 14:55:31 -0700 | [diff] [blame] | 1457 | ret = 0; |
| 1458 | out_finish: |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1459 | blkg_conf_finish(&ctx); |
Tejun Heo | 36aa9e5 | 2015-08-18 14:55:31 -0700 | [diff] [blame] | 1460 | return ret ?: nbytes; |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1461 | } |
| 1462 | |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1463 | static ssize_t tg_set_conf_u64(struct kernfs_open_file *of, |
| 1464 | char *buf, size_t nbytes, loff_t off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1465 | { |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1466 | return tg_set_conf(of, buf, nbytes, off, true); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1467 | } |
| 1468 | |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1469 | static ssize_t tg_set_conf_uint(struct kernfs_open_file *of, |
| 1470 | char *buf, size_t nbytes, loff_t off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1471 | { |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1472 | return tg_set_conf(of, buf, nbytes, off, false); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1473 | } |
| 1474 | |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1475 | static struct cftype throtl_legacy_files[] = { |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1476 | { |
| 1477 | .name = "throttle.read_bps_device", |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1478 | .private = offsetof(struct throtl_grp, bps[READ][LIMIT_MAX]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1479 | .seq_show = tg_print_conf_u64, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1480 | .write = tg_set_conf_u64, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1481 | }, |
| 1482 | { |
| 1483 | .name = "throttle.write_bps_device", |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1484 | .private = offsetof(struct throtl_grp, bps[WRITE][LIMIT_MAX]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1485 | .seq_show = tg_print_conf_u64, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1486 | .write = tg_set_conf_u64, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1487 | }, |
| 1488 | { |
| 1489 | .name = "throttle.read_iops_device", |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1490 | .private = offsetof(struct throtl_grp, iops[READ][LIMIT_MAX]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1491 | .seq_show = tg_print_conf_uint, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1492 | .write = tg_set_conf_uint, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1493 | }, |
| 1494 | { |
| 1495 | .name = "throttle.write_iops_device", |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1496 | .private = offsetof(struct throtl_grp, iops[WRITE][LIMIT_MAX]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1497 | .seq_show = tg_print_conf_uint, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1498 | .write = tg_set_conf_uint, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1499 | }, |
| 1500 | { |
| 1501 | .name = "throttle.io_service_bytes", |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 1502 | .private = (unsigned long)&blkcg_policy_throtl, |
| 1503 | .seq_show = blkg_print_stat_bytes, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1504 | }, |
| 1505 | { |
| 1506 | .name = "throttle.io_serviced", |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 1507 | .private = (unsigned long)&blkcg_policy_throtl, |
| 1508 | .seq_show = blkg_print_stat_ios, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1509 | }, |
| 1510 | { } /* terminate */ |
| 1511 | }; |
| 1512 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1513 | static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd, |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1514 | int off) |
| 1515 | { |
| 1516 | struct throtl_grp *tg = pd_to_tg(pd); |
| 1517 | const char *dname = blkg_dev_name(pd->blkg); |
| 1518 | char bufs[4][21] = { "max", "max", "max", "max" }; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1519 | u64 bps_dft; |
| 1520 | unsigned int iops_dft; |
Shaohua Li | ada75b6 | 2017-03-27 10:51:42 -0700 | [diff] [blame] | 1521 | char idle_time[26] = ""; |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 1522 | char latency_time[26] = ""; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1523 | |
| 1524 | if (!dname) |
| 1525 | return 0; |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1526 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1527 | if (off == LIMIT_LOW) { |
| 1528 | bps_dft = 0; |
| 1529 | iops_dft = 0; |
| 1530 | } else { |
| 1531 | bps_dft = U64_MAX; |
| 1532 | iops_dft = UINT_MAX; |
| 1533 | } |
| 1534 | |
| 1535 | if (tg->bps_conf[READ][off] == bps_dft && |
| 1536 | tg->bps_conf[WRITE][off] == bps_dft && |
| 1537 | tg->iops_conf[READ][off] == iops_dft && |
Shaohua Li | ada75b6 | 2017-03-27 10:51:42 -0700 | [diff] [blame] | 1538 | tg->iops_conf[WRITE][off] == iops_dft && |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 1539 | (off != LIMIT_LOW || |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 1540 | (tg->idletime_threshold_conf == DFL_IDLE_THRESHOLD && |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1541 | tg->latency_target_conf == DFL_LATENCY_TARGET))) |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1542 | return 0; |
| 1543 | |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1544 | if (tg->bps_conf[READ][off] != U64_MAX) |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1545 | snprintf(bufs[0], sizeof(bufs[0]), "%llu", |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1546 | tg->bps_conf[READ][off]); |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1547 | if (tg->bps_conf[WRITE][off] != U64_MAX) |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1548 | snprintf(bufs[1], sizeof(bufs[1]), "%llu", |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1549 | tg->bps_conf[WRITE][off]); |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1550 | if (tg->iops_conf[READ][off] != UINT_MAX) |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1551 | snprintf(bufs[2], sizeof(bufs[2]), "%u", |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1552 | tg->iops_conf[READ][off]); |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1553 | if (tg->iops_conf[WRITE][off] != UINT_MAX) |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 1554 | snprintf(bufs[3], sizeof(bufs[3]), "%u", |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1555 | tg->iops_conf[WRITE][off]); |
Shaohua Li | ada75b6 | 2017-03-27 10:51:42 -0700 | [diff] [blame] | 1556 | if (off == LIMIT_LOW) { |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1557 | if (tg->idletime_threshold_conf == ULONG_MAX) |
Shaohua Li | ada75b6 | 2017-03-27 10:51:42 -0700 | [diff] [blame] | 1558 | strcpy(idle_time, " idle=max"); |
| 1559 | else |
| 1560 | snprintf(idle_time, sizeof(idle_time), " idle=%lu", |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1561 | tg->idletime_threshold_conf); |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 1562 | |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1563 | if (tg->latency_target_conf == ULONG_MAX) |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 1564 | strcpy(latency_time, " latency=max"); |
| 1565 | else |
| 1566 | snprintf(latency_time, sizeof(latency_time), |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1567 | " latency=%lu", tg->latency_target_conf); |
Shaohua Li | ada75b6 | 2017-03-27 10:51:42 -0700 | [diff] [blame] | 1568 | } |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1569 | |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 1570 | seq_printf(sf, "%s rbps=%s wbps=%s riops=%s wiops=%s%s%s\n", |
| 1571 | dname, bufs[0], bufs[1], bufs[2], bufs[3], idle_time, |
| 1572 | latency_time); |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1573 | return 0; |
| 1574 | } |
| 1575 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1576 | static int tg_print_limit(struct seq_file *sf, void *v) |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1577 | { |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1578 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_limit, |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1579 | &blkcg_policy_throtl, seq_cft(sf)->private, false); |
| 1580 | return 0; |
| 1581 | } |
| 1582 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1583 | static ssize_t tg_set_limit(struct kernfs_open_file *of, |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1584 | char *buf, size_t nbytes, loff_t off) |
| 1585 | { |
| 1586 | struct blkcg *blkcg = css_to_blkcg(of_css(of)); |
| 1587 | struct blkg_conf_ctx ctx; |
| 1588 | struct throtl_grp *tg; |
| 1589 | u64 v[4]; |
Shaohua Li | ada75b6 | 2017-03-27 10:51:42 -0700 | [diff] [blame] | 1590 | unsigned long idle_time; |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 1591 | unsigned long latency_time; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1592 | int ret; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1593 | int index = of_cft(of)->private; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1594 | |
| 1595 | ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx); |
| 1596 | if (ret) |
| 1597 | return ret; |
| 1598 | |
| 1599 | tg = blkg_to_tg(ctx.blkg); |
| 1600 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1601 | v[0] = tg->bps_conf[READ][index]; |
| 1602 | v[1] = tg->bps_conf[WRITE][index]; |
| 1603 | v[2] = tg->iops_conf[READ][index]; |
| 1604 | v[3] = tg->iops_conf[WRITE][index]; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1605 | |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1606 | idle_time = tg->idletime_threshold_conf; |
| 1607 | latency_time = tg->latency_target_conf; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1608 | while (true) { |
| 1609 | char tok[27]; /* wiops=18446744073709551616 */ |
| 1610 | char *p; |
Shaohua Li | 2ab5492 | 2017-03-27 10:51:29 -0700 | [diff] [blame] | 1611 | u64 val = U64_MAX; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1612 | int len; |
| 1613 | |
| 1614 | if (sscanf(ctx.body, "%26s%n", tok, &len) != 1) |
| 1615 | break; |
| 1616 | if (tok[0] == '\0') |
| 1617 | break; |
| 1618 | ctx.body += len; |
| 1619 | |
| 1620 | ret = -EINVAL; |
| 1621 | p = tok; |
| 1622 | strsep(&p, "="); |
| 1623 | if (!p || (sscanf(p, "%llu", &val) != 1 && strcmp(p, "max"))) |
| 1624 | goto out_finish; |
| 1625 | |
| 1626 | ret = -ERANGE; |
| 1627 | if (!val) |
| 1628 | goto out_finish; |
| 1629 | |
| 1630 | ret = -EINVAL; |
| 1631 | if (!strcmp(tok, "rbps")) |
| 1632 | v[0] = val; |
| 1633 | else if (!strcmp(tok, "wbps")) |
| 1634 | v[1] = val; |
| 1635 | else if (!strcmp(tok, "riops")) |
| 1636 | v[2] = min_t(u64, val, UINT_MAX); |
| 1637 | else if (!strcmp(tok, "wiops")) |
| 1638 | v[3] = min_t(u64, val, UINT_MAX); |
Shaohua Li | ada75b6 | 2017-03-27 10:51:42 -0700 | [diff] [blame] | 1639 | else if (off == LIMIT_LOW && !strcmp(tok, "idle")) |
| 1640 | idle_time = val; |
Shaohua Li | ec80991 | 2017-03-27 10:51:44 -0700 | [diff] [blame] | 1641 | else if (off == LIMIT_LOW && !strcmp(tok, "latency")) |
| 1642 | latency_time = val; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1643 | else |
| 1644 | goto out_finish; |
| 1645 | } |
| 1646 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1647 | tg->bps_conf[READ][index] = v[0]; |
| 1648 | tg->bps_conf[WRITE][index] = v[1]; |
| 1649 | tg->iops_conf[READ][index] = v[2]; |
| 1650 | tg->iops_conf[WRITE][index] = v[3]; |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1651 | |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1652 | if (index == LIMIT_MAX) { |
| 1653 | tg->bps[READ][index] = v[0]; |
| 1654 | tg->bps[WRITE][index] = v[1]; |
| 1655 | tg->iops[READ][index] = v[2]; |
| 1656 | tg->iops[WRITE][index] = v[3]; |
| 1657 | } |
| 1658 | tg->bps[READ][LIMIT_LOW] = min(tg->bps_conf[READ][LIMIT_LOW], |
| 1659 | tg->bps_conf[READ][LIMIT_MAX]); |
| 1660 | tg->bps[WRITE][LIMIT_LOW] = min(tg->bps_conf[WRITE][LIMIT_LOW], |
| 1661 | tg->bps_conf[WRITE][LIMIT_MAX]); |
| 1662 | tg->iops[READ][LIMIT_LOW] = min(tg->iops_conf[READ][LIMIT_LOW], |
| 1663 | tg->iops_conf[READ][LIMIT_MAX]); |
| 1664 | tg->iops[WRITE][LIMIT_LOW] = min(tg->iops_conf[WRITE][LIMIT_LOW], |
| 1665 | tg->iops_conf[WRITE][LIMIT_MAX]); |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 1666 | tg->idletime_threshold_conf = idle_time; |
| 1667 | tg->latency_target_conf = latency_time; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1668 | |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 1669 | /* force user to configure all settings for low limit */ |
| 1670 | if (!(tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW] || |
| 1671 | tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) || |
| 1672 | tg->idletime_threshold_conf == DFL_IDLE_THRESHOLD || |
| 1673 | tg->latency_target_conf == DFL_LATENCY_TARGET) { |
| 1674 | tg->bps[READ][LIMIT_LOW] = 0; |
| 1675 | tg->bps[WRITE][LIMIT_LOW] = 0; |
| 1676 | tg->iops[READ][LIMIT_LOW] = 0; |
| 1677 | tg->iops[WRITE][LIMIT_LOW] = 0; |
| 1678 | tg->idletime_threshold = DFL_IDLE_THRESHOLD; |
| 1679 | tg->latency_target = DFL_LATENCY_TARGET; |
| 1680 | } else if (index == LIMIT_LOW) { |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1681 | tg->idletime_threshold = tg->idletime_threshold_conf; |
Shaohua Li | 5b81fc3 | 2017-05-17 13:07:24 -0700 | [diff] [blame] | 1682 | tg->latency_target = tg->latency_target_conf; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1683 | } |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 1684 | |
| 1685 | blk_throtl_update_limit_valid(tg->td); |
| 1686 | if (tg->td->limit_valid[LIMIT_LOW]) { |
| 1687 | if (index == LIMIT_LOW) |
| 1688 | tg->td->limit_index = LIMIT_LOW; |
| 1689 | } else |
| 1690 | tg->td->limit_index = LIMIT_MAX; |
Shaohua Li | 9bb67ae | 2017-05-17 13:07:26 -0700 | [diff] [blame] | 1691 | tg_conf_updated(tg, index == LIMIT_LOW && |
| 1692 | tg->td->limit_valid[LIMIT_LOW]); |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1693 | ret = 0; |
| 1694 | out_finish: |
| 1695 | blkg_conf_finish(&ctx); |
| 1696 | return ret ?: nbytes; |
| 1697 | } |
| 1698 | |
| 1699 | static struct cftype throtl_files[] = { |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1700 | #ifdef CONFIG_BLK_DEV_THROTTLING_LOW |
| 1701 | { |
| 1702 | .name = "low", |
| 1703 | .flags = CFTYPE_NOT_ON_ROOT, |
| 1704 | .seq_show = tg_print_limit, |
| 1705 | .write = tg_set_limit, |
| 1706 | .private = LIMIT_LOW, |
| 1707 | }, |
| 1708 | #endif |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1709 | { |
| 1710 | .name = "max", |
| 1711 | .flags = CFTYPE_NOT_ON_ROOT, |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1712 | .seq_show = tg_print_limit, |
| 1713 | .write = tg_set_limit, |
| 1714 | .private = LIMIT_MAX, |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1715 | }, |
| 1716 | { } /* terminate */ |
| 1717 | }; |
| 1718 | |
Vivek Goyal | da52777 | 2011-03-02 19:05:33 -0500 | [diff] [blame] | 1719 | static void throtl_shutdown_wq(struct request_queue *q) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1720 | { |
| 1721 | struct throtl_data *td = q->td; |
| 1722 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1723 | cancel_work_sync(&td->dispatch_work); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1724 | } |
| 1725 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1726 | static struct blkcg_policy blkcg_policy_throtl = { |
Tejun Heo | 2ee867dc | 2015-08-18 14:55:34 -0700 | [diff] [blame] | 1727 | .dfl_cftypes = throtl_files, |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1728 | .legacy_cftypes = throtl_legacy_files, |
Tejun Heo | f9fcc2d | 2012-04-16 13:57:27 -0700 | [diff] [blame] | 1729 | |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 1730 | .pd_alloc_fn = throtl_pd_alloc, |
Tejun Heo | f9fcc2d | 2012-04-16 13:57:27 -0700 | [diff] [blame] | 1731 | .pd_init_fn = throtl_pd_init, |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1732 | .pd_online_fn = throtl_pd_online, |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 1733 | .pd_offline_fn = throtl_pd_offline, |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 1734 | .pd_free_fn = throtl_pd_free, |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1735 | }; |
| 1736 | |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1737 | static unsigned long __tg_last_low_overflow_time(struct throtl_grp *tg) |
| 1738 | { |
| 1739 | unsigned long rtime = jiffies, wtime = jiffies; |
| 1740 | |
| 1741 | if (tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW]) |
| 1742 | rtime = tg->last_low_overflow_time[READ]; |
| 1743 | if (tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) |
| 1744 | wtime = tg->last_low_overflow_time[WRITE]; |
| 1745 | return min(rtime, wtime); |
| 1746 | } |
| 1747 | |
| 1748 | /* tg should not be an intermediate node */ |
| 1749 | static unsigned long tg_last_low_overflow_time(struct throtl_grp *tg) |
| 1750 | { |
| 1751 | struct throtl_service_queue *parent_sq; |
| 1752 | struct throtl_grp *parent = tg; |
| 1753 | unsigned long ret = __tg_last_low_overflow_time(tg); |
| 1754 | |
| 1755 | while (true) { |
| 1756 | parent_sq = parent->service_queue.parent_sq; |
| 1757 | parent = sq_to_tg(parent_sq); |
| 1758 | if (!parent) |
| 1759 | break; |
| 1760 | |
| 1761 | /* |
| 1762 | * The parent doesn't have low limit, it always reaches low |
| 1763 | * limit. Its overflow time is useless for children |
| 1764 | */ |
| 1765 | if (!parent->bps[READ][LIMIT_LOW] && |
| 1766 | !parent->iops[READ][LIMIT_LOW] && |
| 1767 | !parent->bps[WRITE][LIMIT_LOW] && |
| 1768 | !parent->iops[WRITE][LIMIT_LOW]) |
| 1769 | continue; |
| 1770 | if (time_after(__tg_last_low_overflow_time(parent), ret)) |
| 1771 | ret = __tg_last_low_overflow_time(parent); |
| 1772 | } |
| 1773 | return ret; |
| 1774 | } |
| 1775 | |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 1776 | static bool throtl_tg_is_idle(struct throtl_grp *tg) |
| 1777 | { |
| 1778 | /* |
| 1779 | * cgroup is idle if: |
| 1780 | * - single idle is too long, longer than a fixed value (in case user |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 1781 | * configure a too big threshold) or 4 times of idletime threshold |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 1782 | * - average think time is more than threshold |
Shaohua Li | 53696b8 | 2017-03-27 15:19:43 -0700 | [diff] [blame] | 1783 | * - IO latency is largely below threshold |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 1784 | */ |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 1785 | unsigned long time; |
Shaohua Li | 4cff729 | 2017-05-17 13:07:25 -0700 | [diff] [blame] | 1786 | bool ret; |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 1787 | |
Shaohua Li | b4f428e | 2017-05-17 13:07:27 -0700 | [diff] [blame] | 1788 | time = min_t(unsigned long, MAX_IDLE_TIME, 4 * tg->idletime_threshold); |
| 1789 | ret = tg->latency_target == DFL_LATENCY_TARGET || |
| 1790 | tg->idletime_threshold == DFL_IDLE_THRESHOLD || |
| 1791 | (ktime_get_ns() >> 10) - tg->last_finish_time > time || |
| 1792 | tg->avg_idletime > tg->idletime_threshold || |
| 1793 | (tg->latency_target && tg->bio_cnt && |
Shaohua Li | 53696b8 | 2017-03-27 15:19:43 -0700 | [diff] [blame] | 1794 | tg->bad_bio_cnt * 5 < tg->bio_cnt); |
Shaohua Li | 4cff729 | 2017-05-17 13:07:25 -0700 | [diff] [blame] | 1795 | throtl_log(&tg->service_queue, |
| 1796 | "avg_idle=%ld, idle_threshold=%ld, bad_bio=%d, total_bio=%d, is_idle=%d, scale=%d", |
| 1797 | tg->avg_idletime, tg->idletime_threshold, tg->bad_bio_cnt, |
| 1798 | tg->bio_cnt, ret, tg->td->scale); |
| 1799 | return ret; |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 1800 | } |
| 1801 | |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1802 | static bool throtl_tg_can_upgrade(struct throtl_grp *tg) |
| 1803 | { |
| 1804 | struct throtl_service_queue *sq = &tg->service_queue; |
| 1805 | bool read_limit, write_limit; |
| 1806 | |
| 1807 | /* |
| 1808 | * if cgroup reaches low limit (if low limit is 0, the cgroup always |
| 1809 | * reaches), it's ok to upgrade to next limit |
| 1810 | */ |
| 1811 | read_limit = tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW]; |
| 1812 | write_limit = tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]; |
| 1813 | if (!read_limit && !write_limit) |
| 1814 | return true; |
| 1815 | if (read_limit && sq->nr_queued[READ] && |
| 1816 | (!write_limit || sq->nr_queued[WRITE])) |
| 1817 | return true; |
| 1818 | if (write_limit && sq->nr_queued[WRITE] && |
| 1819 | (!read_limit || sq->nr_queued[READ])) |
| 1820 | return true; |
Shaohua Li | aec2424 | 2017-03-27 10:51:39 -0700 | [diff] [blame] | 1821 | |
| 1822 | if (time_after_eq(jiffies, |
Shaohua Li | fa6fb5a | 2017-03-27 10:51:43 -0700 | [diff] [blame] | 1823 | tg_last_low_overflow_time(tg) + tg->td->throtl_slice) && |
| 1824 | throtl_tg_is_idle(tg)) |
Shaohua Li | aec2424 | 2017-03-27 10:51:39 -0700 | [diff] [blame] | 1825 | return true; |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1826 | return false; |
| 1827 | } |
| 1828 | |
| 1829 | static bool throtl_hierarchy_can_upgrade(struct throtl_grp *tg) |
| 1830 | { |
| 1831 | while (true) { |
| 1832 | if (throtl_tg_can_upgrade(tg)) |
| 1833 | return true; |
| 1834 | tg = sq_to_tg(tg->service_queue.parent_sq); |
| 1835 | if (!tg || !tg_to_blkg(tg)->parent) |
| 1836 | return false; |
| 1837 | } |
| 1838 | return false; |
| 1839 | } |
| 1840 | |
| 1841 | static bool throtl_can_upgrade(struct throtl_data *td, |
| 1842 | struct throtl_grp *this_tg) |
| 1843 | { |
| 1844 | struct cgroup_subsys_state *pos_css; |
| 1845 | struct blkcg_gq *blkg; |
| 1846 | |
| 1847 | if (td->limit_index != LIMIT_LOW) |
| 1848 | return false; |
| 1849 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 1850 | if (time_before(jiffies, td->low_downgrade_time + td->throtl_slice)) |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1851 | return false; |
| 1852 | |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1853 | rcu_read_lock(); |
| 1854 | blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { |
| 1855 | struct throtl_grp *tg = blkg_to_tg(blkg); |
| 1856 | |
| 1857 | if (tg == this_tg) |
| 1858 | continue; |
| 1859 | if (!list_empty(&tg_to_blkg(tg)->blkcg->css.children)) |
| 1860 | continue; |
| 1861 | if (!throtl_hierarchy_can_upgrade(tg)) { |
| 1862 | rcu_read_unlock(); |
| 1863 | return false; |
| 1864 | } |
| 1865 | } |
| 1866 | rcu_read_unlock(); |
| 1867 | return true; |
| 1868 | } |
| 1869 | |
Shaohua Li | fa6fb5a | 2017-03-27 10:51:43 -0700 | [diff] [blame] | 1870 | static void throtl_upgrade_check(struct throtl_grp *tg) |
| 1871 | { |
| 1872 | unsigned long now = jiffies; |
| 1873 | |
| 1874 | if (tg->td->limit_index != LIMIT_LOW) |
| 1875 | return; |
| 1876 | |
| 1877 | if (time_after(tg->last_check_time + tg->td->throtl_slice, now)) |
| 1878 | return; |
| 1879 | |
| 1880 | tg->last_check_time = now; |
| 1881 | |
| 1882 | if (!time_after_eq(now, |
| 1883 | __tg_last_low_overflow_time(tg) + tg->td->throtl_slice)) |
| 1884 | return; |
| 1885 | |
| 1886 | if (throtl_can_upgrade(tg->td, NULL)) |
| 1887 | throtl_upgrade_state(tg->td); |
| 1888 | } |
| 1889 | |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1890 | static void throtl_upgrade_state(struct throtl_data *td) |
| 1891 | { |
| 1892 | struct cgroup_subsys_state *pos_css; |
| 1893 | struct blkcg_gq *blkg; |
| 1894 | |
Shaohua Li | 4cff729 | 2017-05-17 13:07:25 -0700 | [diff] [blame] | 1895 | throtl_log(&td->service_queue, "upgrade to max"); |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1896 | td->limit_index = LIMIT_MAX; |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1897 | td->low_upgrade_time = jiffies; |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 1898 | td->scale = 0; |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 1899 | rcu_read_lock(); |
| 1900 | blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) { |
| 1901 | struct throtl_grp *tg = blkg_to_tg(blkg); |
| 1902 | struct throtl_service_queue *sq = &tg->service_queue; |
| 1903 | |
| 1904 | tg->disptime = jiffies - 1; |
| 1905 | throtl_select_dispatch(sq); |
| 1906 | throtl_schedule_next_dispatch(sq, false); |
| 1907 | } |
| 1908 | rcu_read_unlock(); |
| 1909 | throtl_select_dispatch(&td->service_queue); |
| 1910 | throtl_schedule_next_dispatch(&td->service_queue, false); |
| 1911 | queue_work(kthrotld_workqueue, &td->dispatch_work); |
| 1912 | } |
| 1913 | |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1914 | static void throtl_downgrade_state(struct throtl_data *td, int new) |
| 1915 | { |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 1916 | td->scale /= 2; |
| 1917 | |
Shaohua Li | 4cff729 | 2017-05-17 13:07:25 -0700 | [diff] [blame] | 1918 | throtl_log(&td->service_queue, "downgrade, scale %d", td->scale); |
Shaohua Li | 7394e31 | 2017-03-27 10:51:40 -0700 | [diff] [blame] | 1919 | if (td->scale) { |
| 1920 | td->low_upgrade_time = jiffies - td->scale * td->throtl_slice; |
| 1921 | return; |
| 1922 | } |
| 1923 | |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1924 | td->limit_index = new; |
| 1925 | td->low_downgrade_time = jiffies; |
| 1926 | } |
| 1927 | |
| 1928 | static bool throtl_tg_can_downgrade(struct throtl_grp *tg) |
| 1929 | { |
| 1930 | struct throtl_data *td = tg->td; |
| 1931 | unsigned long now = jiffies; |
| 1932 | |
| 1933 | /* |
| 1934 | * If cgroup is below low limit, consider downgrade and throttle other |
| 1935 | * cgroups |
| 1936 | */ |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 1937 | if (time_after_eq(now, td->low_upgrade_time + td->throtl_slice) && |
| 1938 | time_after_eq(now, tg_last_low_overflow_time(tg) + |
Shaohua Li | fa6fb5a | 2017-03-27 10:51:43 -0700 | [diff] [blame] | 1939 | td->throtl_slice) && |
| 1940 | (!throtl_tg_is_idle(tg) || |
| 1941 | !list_empty(&tg_to_blkg(tg)->blkcg->css.children))) |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1942 | return true; |
| 1943 | return false; |
| 1944 | } |
| 1945 | |
| 1946 | static bool throtl_hierarchy_can_downgrade(struct throtl_grp *tg) |
| 1947 | { |
| 1948 | while (true) { |
| 1949 | if (!throtl_tg_can_downgrade(tg)) |
| 1950 | return false; |
| 1951 | tg = sq_to_tg(tg->service_queue.parent_sq); |
| 1952 | if (!tg || !tg_to_blkg(tg)->parent) |
| 1953 | break; |
| 1954 | } |
| 1955 | return true; |
| 1956 | } |
| 1957 | |
| 1958 | static void throtl_downgrade_check(struct throtl_grp *tg) |
| 1959 | { |
| 1960 | uint64_t bps; |
| 1961 | unsigned int iops; |
| 1962 | unsigned long elapsed_time; |
| 1963 | unsigned long now = jiffies; |
| 1964 | |
| 1965 | if (tg->td->limit_index != LIMIT_MAX || |
| 1966 | !tg->td->limit_valid[LIMIT_LOW]) |
| 1967 | return; |
| 1968 | if (!list_empty(&tg_to_blkg(tg)->blkcg->css.children)) |
| 1969 | return; |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 1970 | if (time_after(tg->last_check_time + tg->td->throtl_slice, now)) |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1971 | return; |
| 1972 | |
| 1973 | elapsed_time = now - tg->last_check_time; |
| 1974 | tg->last_check_time = now; |
| 1975 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 1976 | if (time_before(now, tg_last_low_overflow_time(tg) + |
| 1977 | tg->td->throtl_slice)) |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 1978 | return; |
| 1979 | |
| 1980 | if (tg->bps[READ][LIMIT_LOW]) { |
| 1981 | bps = tg->last_bytes_disp[READ] * HZ; |
| 1982 | do_div(bps, elapsed_time); |
| 1983 | if (bps >= tg->bps[READ][LIMIT_LOW]) |
| 1984 | tg->last_low_overflow_time[READ] = now; |
| 1985 | } |
| 1986 | |
| 1987 | if (tg->bps[WRITE][LIMIT_LOW]) { |
| 1988 | bps = tg->last_bytes_disp[WRITE] * HZ; |
| 1989 | do_div(bps, elapsed_time); |
| 1990 | if (bps >= tg->bps[WRITE][LIMIT_LOW]) |
| 1991 | tg->last_low_overflow_time[WRITE] = now; |
| 1992 | } |
| 1993 | |
| 1994 | if (tg->iops[READ][LIMIT_LOW]) { |
| 1995 | iops = tg->last_io_disp[READ] * HZ / elapsed_time; |
| 1996 | if (iops >= tg->iops[READ][LIMIT_LOW]) |
| 1997 | tg->last_low_overflow_time[READ] = now; |
| 1998 | } |
| 1999 | |
| 2000 | if (tg->iops[WRITE][LIMIT_LOW]) { |
| 2001 | iops = tg->last_io_disp[WRITE] * HZ / elapsed_time; |
| 2002 | if (iops >= tg->iops[WRITE][LIMIT_LOW]) |
| 2003 | tg->last_low_overflow_time[WRITE] = now; |
| 2004 | } |
| 2005 | |
| 2006 | /* |
| 2007 | * If cgroup is below low limit, consider downgrade and throttle other |
| 2008 | * cgroups |
| 2009 | */ |
| 2010 | if (throtl_hierarchy_can_downgrade(tg)) |
| 2011 | throtl_downgrade_state(tg->td, LIMIT_LOW); |
| 2012 | |
| 2013 | tg->last_bytes_disp[READ] = 0; |
| 2014 | tg->last_bytes_disp[WRITE] = 0; |
| 2015 | tg->last_io_disp[READ] = 0; |
| 2016 | tg->last_io_disp[WRITE] = 0; |
| 2017 | } |
| 2018 | |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2019 | static void blk_throtl_update_idletime(struct throtl_grp *tg) |
| 2020 | { |
| 2021 | unsigned long now = ktime_get_ns() >> 10; |
| 2022 | unsigned long last_finish_time = tg->last_finish_time; |
| 2023 | |
| 2024 | if (now <= last_finish_time || last_finish_time == 0 || |
| 2025 | last_finish_time == tg->checked_last_finish_time) |
| 2026 | return; |
| 2027 | |
| 2028 | tg->avg_idletime = (tg->avg_idletime * 7 + now - last_finish_time) >> 3; |
| 2029 | tg->checked_last_finish_time = last_finish_time; |
| 2030 | } |
| 2031 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2032 | #ifdef CONFIG_BLK_DEV_THROTTLING_LOW |
| 2033 | static void throtl_update_latency_buckets(struct throtl_data *td) |
| 2034 | { |
| 2035 | struct avg_latency_bucket avg_latency[LATENCY_BUCKET_SIZE]; |
| 2036 | int i, cpu; |
| 2037 | unsigned long last_latency = 0; |
| 2038 | unsigned long latency; |
| 2039 | |
| 2040 | if (!blk_queue_nonrot(td->queue)) |
| 2041 | return; |
| 2042 | if (time_before(jiffies, td->last_calculate_time + HZ)) |
| 2043 | return; |
| 2044 | td->last_calculate_time = jiffies; |
| 2045 | |
| 2046 | memset(avg_latency, 0, sizeof(avg_latency)); |
| 2047 | for (i = 0; i < LATENCY_BUCKET_SIZE; i++) { |
| 2048 | struct latency_bucket *tmp = &td->tmp_buckets[i]; |
| 2049 | |
| 2050 | for_each_possible_cpu(cpu) { |
| 2051 | struct latency_bucket *bucket; |
| 2052 | |
| 2053 | /* this isn't race free, but ok in practice */ |
| 2054 | bucket = per_cpu_ptr(td->latency_buckets, cpu); |
| 2055 | tmp->total_latency += bucket[i].total_latency; |
| 2056 | tmp->samples += bucket[i].samples; |
| 2057 | bucket[i].total_latency = 0; |
| 2058 | bucket[i].samples = 0; |
| 2059 | } |
| 2060 | |
| 2061 | if (tmp->samples >= 32) { |
| 2062 | int samples = tmp->samples; |
| 2063 | |
| 2064 | latency = tmp->total_latency; |
| 2065 | |
| 2066 | tmp->total_latency = 0; |
| 2067 | tmp->samples = 0; |
| 2068 | latency /= samples; |
| 2069 | if (latency == 0) |
| 2070 | continue; |
| 2071 | avg_latency[i].latency = latency; |
| 2072 | } |
| 2073 | } |
| 2074 | |
| 2075 | for (i = 0; i < LATENCY_BUCKET_SIZE; i++) { |
| 2076 | if (!avg_latency[i].latency) { |
| 2077 | if (td->avg_buckets[i].latency < last_latency) |
| 2078 | td->avg_buckets[i].latency = last_latency; |
| 2079 | continue; |
| 2080 | } |
| 2081 | |
| 2082 | if (!td->avg_buckets[i].valid) |
| 2083 | latency = avg_latency[i].latency; |
| 2084 | else |
| 2085 | latency = (td->avg_buckets[i].latency * 7 + |
| 2086 | avg_latency[i].latency) >> 3; |
| 2087 | |
| 2088 | td->avg_buckets[i].latency = max(latency, last_latency); |
| 2089 | td->avg_buckets[i].valid = true; |
| 2090 | last_latency = td->avg_buckets[i].latency; |
| 2091 | } |
Shaohua Li | 4cff729 | 2017-05-17 13:07:25 -0700 | [diff] [blame] | 2092 | |
| 2093 | for (i = 0; i < LATENCY_BUCKET_SIZE; i++) |
| 2094 | throtl_log(&td->service_queue, |
| 2095 | "Latency bucket %d: latency=%ld, valid=%d", i, |
| 2096 | td->avg_buckets[i].latency, td->avg_buckets[i].valid); |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2097 | } |
| 2098 | #else |
| 2099 | static inline void throtl_update_latency_buckets(struct throtl_data *td) |
| 2100 | { |
| 2101 | } |
| 2102 | #endif |
| 2103 | |
Jens Axboe | 2bc19cd | 2017-04-20 09:41:36 -0600 | [diff] [blame] | 2104 | static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio) |
| 2105 | { |
| 2106 | #ifdef CONFIG_BLK_DEV_THROTTLING_LOW |
| 2107 | int ret; |
| 2108 | |
| 2109 | ret = bio_associate_current(bio); |
| 2110 | if (ret == 0 || ret == -EBUSY) |
| 2111 | bio->bi_cg_private = tg; |
| 2112 | blk_stat_set_issue(&bio->bi_issue_stat, bio_sectors(bio)); |
| 2113 | #else |
| 2114 | bio_associate_current(bio); |
| 2115 | #endif |
| 2116 | } |
| 2117 | |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 2118 | bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, |
| 2119 | struct bio *bio) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2120 | { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2121 | struct throtl_qnode *qn = NULL; |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 2122 | struct throtl_grp *tg = blkg_to_tg(blkg ?: q->root_blkg); |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2123 | struct throtl_service_queue *sq; |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2124 | bool rw = bio_data_dir(bio); |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 2125 | bool throttled = false; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2126 | struct throtl_data *td = tg->td; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2127 | |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 2128 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 2129 | |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 2130 | /* see throtl_charge_bio() */ |
Christoph Hellwig | 8d2bbd4 | 2016-10-20 15:12:12 +0200 | [diff] [blame] | 2131 | if (bio_flagged(bio, BIO_THROTTLED) || !tg->has_rules[rw]) |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 2132 | goto out; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2133 | |
| 2134 | spin_lock_irq(q->queue_lock); |
Tejun Heo | c9589f0 | 2015-08-18 14:55:19 -0700 | [diff] [blame] | 2135 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2136 | throtl_update_latency_buckets(td); |
| 2137 | |
Tejun Heo | c9589f0 | 2015-08-18 14:55:19 -0700 | [diff] [blame] | 2138 | if (unlikely(blk_queue_bypass(q))) |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 2139 | goto out_unlock; |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 2140 | |
Jens Axboe | 2bc19cd | 2017-04-20 09:41:36 -0600 | [diff] [blame] | 2141 | blk_throtl_assoc_bio(tg, bio); |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2142 | blk_throtl_update_idletime(tg); |
| 2143 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2144 | sq = &tg->service_queue; |
| 2145 | |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 2146 | again: |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2147 | while (true) { |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 2148 | if (tg->last_low_overflow_time[rw] == 0) |
| 2149 | tg->last_low_overflow_time[rw] = jiffies; |
| 2150 | throtl_downgrade_check(tg); |
Shaohua Li | fa6fb5a | 2017-03-27 10:51:43 -0700 | [diff] [blame] | 2151 | throtl_upgrade_check(tg); |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2152 | /* throtl is FIFO - if bios are already queued, should queue */ |
| 2153 | if (sq->nr_queued[rw]) |
| 2154 | break; |
Vivek Goyal | de701c7 | 2011-03-07 21:09:32 +0100 | [diff] [blame] | 2155 | |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2156 | /* if above limits, break to queue */ |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 2157 | if (!tg_may_dispatch(tg, bio, NULL)) { |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 2158 | tg->last_low_overflow_time[rw] = jiffies; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2159 | if (throtl_can_upgrade(td, tg)) { |
| 2160 | throtl_upgrade_state(td); |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 2161 | goto again; |
| 2162 | } |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2163 | break; |
Shaohua Li | c79892c | 2017-03-27 10:51:34 -0700 | [diff] [blame] | 2164 | } |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2165 | |
| 2166 | /* within limits, let's charge and dispatch directly */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2167 | throtl_charge_bio(tg, bio); |
Vivek Goyal | 04521db | 2011-03-22 21:54:29 +0100 | [diff] [blame] | 2168 | |
| 2169 | /* |
| 2170 | * We need to trim slice even when bios are not being queued |
| 2171 | * otherwise it might happen that a bio is not queued for |
| 2172 | * a long time and slice keeps on extending and trim is not |
| 2173 | * called for a long time. Now if limits are reduced suddenly |
| 2174 | * we take into account all the IO dispatched so far at new |
| 2175 | * low rate and * newly queued IO gets a really long dispatch |
| 2176 | * time. |
| 2177 | * |
| 2178 | * So keep on trimming slice even if bio is not queued. |
| 2179 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 2180 | throtl_trim_slice(tg, rw); |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2181 | |
| 2182 | /* |
| 2183 | * @bio passed through this layer without being throttled. |
| 2184 | * Climb up the ladder. If we''re already at the top, it |
| 2185 | * can be executed directly. |
| 2186 | */ |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2187 | qn = &tg->qnode_on_parent[rw]; |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2188 | sq = sq->parent_sq; |
| 2189 | tg = sq_to_tg(sq); |
| 2190 | if (!tg) |
| 2191 | goto out_unlock; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2192 | } |
| 2193 | |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2194 | /* out-of-limit, queue to @tg */ |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 2195 | throtl_log(sq, "[%c] bio. bdisp=%llu sz=%u bps=%llu iodisp=%u iops=%u queued=%d/%d", |
| 2196 | rw == READ ? 'R' : 'W', |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 2197 | tg->bytes_disp[rw], bio->bi_iter.bi_size, |
| 2198 | tg_bps_limit(tg, rw), |
| 2199 | tg->io_disp[rw], tg_iops_limit(tg, rw), |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 2200 | sq->nr_queued[READ], sq->nr_queued[WRITE]); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2201 | |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 2202 | tg->last_low_overflow_time[rw] = jiffies; |
| 2203 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2204 | td->nr_queued[rw]++; |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2205 | throtl_add_bio_tg(bio, qn, tg); |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 2206 | throttled = true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2207 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2208 | /* |
| 2209 | * Update @tg's dispatch time and force schedule dispatch if @tg |
| 2210 | * was empty before @bio. The forced scheduling isn't likely to |
| 2211 | * cause undue delay as @bio is likely to be dispatched directly if |
| 2212 | * its @tg's disptime is not in the future. |
| 2213 | */ |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2214 | if (tg->flags & THROTL_TG_WAS_EMPTY) { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 2215 | tg_update_disptime(tg); |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2216 | throtl_schedule_next_dispatch(tg->service_queue.parent_sq, true); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2217 | } |
| 2218 | |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 2219 | out_unlock: |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2220 | spin_unlock_irq(q->queue_lock); |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 2221 | out: |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 2222 | /* |
| 2223 | * As multiple blk-throtls may stack in the same issue path, we |
| 2224 | * don't want bios to leave with the flag set. Clear the flag if |
| 2225 | * being issued. |
| 2226 | */ |
| 2227 | if (!throttled) |
Christoph Hellwig | 8d2bbd4 | 2016-10-20 15:12:12 +0200 | [diff] [blame] | 2228 | bio_clear_flag(bio, BIO_THROTTLED); |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2229 | |
| 2230 | #ifdef CONFIG_BLK_DEV_THROTTLING_LOW |
| 2231 | if (throttled || !td->track_bio_latency) |
| 2232 | bio->bi_issue_stat.stat |= SKIP_LATENCY; |
| 2233 | #endif |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 2234 | return throttled; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2235 | } |
| 2236 | |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2237 | #ifdef CONFIG_BLK_DEV_THROTTLING_LOW |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2238 | static void throtl_track_latency(struct throtl_data *td, sector_t size, |
| 2239 | int op, unsigned long time) |
| 2240 | { |
| 2241 | struct latency_bucket *latency; |
| 2242 | int index; |
| 2243 | |
| 2244 | if (!td || td->limit_index != LIMIT_LOW || op != REQ_OP_READ || |
| 2245 | !blk_queue_nonrot(td->queue)) |
| 2246 | return; |
| 2247 | |
| 2248 | index = request_bucket_index(size); |
| 2249 | |
| 2250 | latency = get_cpu_ptr(td->latency_buckets); |
| 2251 | latency[index].total_latency += time; |
| 2252 | latency[index].samples++; |
| 2253 | put_cpu_ptr(td->latency_buckets); |
| 2254 | } |
| 2255 | |
| 2256 | void blk_throtl_stat_add(struct request *rq, u64 time_ns) |
| 2257 | { |
| 2258 | struct request_queue *q = rq->q; |
| 2259 | struct throtl_data *td = q->td; |
| 2260 | |
| 2261 | throtl_track_latency(td, blk_stat_size(&rq->issue_stat), |
| 2262 | req_op(rq), time_ns >> 10); |
| 2263 | } |
| 2264 | |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2265 | void blk_throtl_bio_endio(struct bio *bio) |
| 2266 | { |
| 2267 | struct throtl_grp *tg; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2268 | u64 finish_time_ns; |
| 2269 | unsigned long finish_time; |
| 2270 | unsigned long start_time; |
| 2271 | unsigned long lat; |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2272 | |
| 2273 | tg = bio->bi_cg_private; |
| 2274 | if (!tg) |
| 2275 | return; |
| 2276 | bio->bi_cg_private = NULL; |
| 2277 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2278 | finish_time_ns = ktime_get_ns(); |
| 2279 | tg->last_finish_time = finish_time_ns >> 10; |
| 2280 | |
| 2281 | start_time = blk_stat_time(&bio->bi_issue_stat) >> 10; |
| 2282 | finish_time = __blk_stat_time(finish_time_ns) >> 10; |
Shaohua Li | 53696b8 | 2017-03-27 15:19:43 -0700 | [diff] [blame] | 2283 | if (!start_time || finish_time <= start_time) |
| 2284 | return; |
| 2285 | |
| 2286 | lat = finish_time - start_time; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2287 | /* this is only for bio based driver */ |
Shaohua Li | 53696b8 | 2017-03-27 15:19:43 -0700 | [diff] [blame] | 2288 | if (!(bio->bi_issue_stat.stat & SKIP_LATENCY)) |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2289 | throtl_track_latency(tg->td, blk_stat_size(&bio->bi_issue_stat), |
| 2290 | bio_op(bio), lat); |
Shaohua Li | 53696b8 | 2017-03-27 15:19:43 -0700 | [diff] [blame] | 2291 | |
Shaohua Li | 6679a90 | 2017-06-06 12:40:43 -0700 | [diff] [blame] | 2292 | if (tg->latency_target && lat >= tg->td->filtered_latency) { |
Shaohua Li | 53696b8 | 2017-03-27 15:19:43 -0700 | [diff] [blame] | 2293 | int bucket; |
| 2294 | unsigned int threshold; |
| 2295 | |
| 2296 | bucket = request_bucket_index( |
| 2297 | blk_stat_size(&bio->bi_issue_stat)); |
| 2298 | threshold = tg->td->avg_buckets[bucket].latency + |
| 2299 | tg->latency_target; |
| 2300 | if (lat > threshold) |
| 2301 | tg->bad_bio_cnt++; |
| 2302 | /* |
| 2303 | * Not race free, could get wrong count, which means cgroups |
| 2304 | * will be throttled |
| 2305 | */ |
| 2306 | tg->bio_cnt++; |
| 2307 | } |
| 2308 | |
| 2309 | if (time_after(jiffies, tg->bio_cnt_reset_time) || tg->bio_cnt > 1024) { |
| 2310 | tg->bio_cnt_reset_time = tg->td->throtl_slice + jiffies; |
| 2311 | tg->bio_cnt /= 2; |
| 2312 | tg->bad_bio_cnt /= 2; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2313 | } |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2314 | } |
| 2315 | #endif |
| 2316 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2317 | /* |
| 2318 | * Dispatch all bios from all children tg's queued on @parent_sq. On |
| 2319 | * return, @parent_sq is guaranteed to not have any active children tg's |
| 2320 | * and all bios from previously active tg's are on @parent_sq->bio_lists[]. |
| 2321 | */ |
| 2322 | static void tg_drain_bios(struct throtl_service_queue *parent_sq) |
| 2323 | { |
| 2324 | struct throtl_grp *tg; |
| 2325 | |
| 2326 | while ((tg = throtl_rb_first(parent_sq))) { |
| 2327 | struct throtl_service_queue *sq = &tg->service_queue; |
| 2328 | struct bio *bio; |
| 2329 | |
| 2330 | throtl_dequeue_tg(tg); |
| 2331 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2332 | while ((bio = throtl_peek_queued(&sq->queued[READ]))) |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2333 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2334 | while ((bio = throtl_peek_queued(&sq->queued[WRITE]))) |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2335 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
| 2336 | } |
| 2337 | } |
| 2338 | |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 2339 | /** |
| 2340 | * blk_throtl_drain - drain throttled bios |
| 2341 | * @q: request_queue to drain throttled bios for |
| 2342 | * |
| 2343 | * Dispatch all currently throttled bios on @q through ->make_request_fn(). |
| 2344 | */ |
| 2345 | void blk_throtl_drain(struct request_queue *q) |
| 2346 | __releases(q->queue_lock) __acquires(q->queue_lock) |
| 2347 | { |
| 2348 | struct throtl_data *td = q->td; |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2349 | struct blkcg_gq *blkg; |
Tejun Heo | 492eb21 | 2013-08-08 20:11:25 -0400 | [diff] [blame] | 2350 | struct cgroup_subsys_state *pos_css; |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 2351 | struct bio *bio; |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2352 | int rw; |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 2353 | |
Andi Kleen | 8bcb6c7 | 2012-03-30 12:33:28 +0200 | [diff] [blame] | 2354 | queue_lockdep_assert_held(q); |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2355 | rcu_read_lock(); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 2356 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2357 | /* |
| 2358 | * Drain each tg while doing post-order walk on the blkg tree, so |
| 2359 | * that all bios are propagated to td->service_queue. It'd be |
| 2360 | * better to walk service_queue tree directly but blkg walk is |
| 2361 | * easier. |
| 2362 | */ |
Tejun Heo | 492eb21 | 2013-08-08 20:11:25 -0400 | [diff] [blame] | 2363 | blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2364 | tg_drain_bios(&blkg_to_tg(blkg)->service_queue); |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2365 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2366 | /* finally, transfer bios from top-level tg's into the td */ |
| 2367 | tg_drain_bios(&td->service_queue); |
| 2368 | |
| 2369 | rcu_read_unlock(); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 2370 | spin_unlock_irq(q->queue_lock); |
| 2371 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 2372 | /* all bios now should be in td->service_queue, issue them */ |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2373 | for (rw = READ; rw <= WRITE; rw++) |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 2374 | while ((bio = throtl_pop_queued(&td->service_queue.queued[rw], |
| 2375 | NULL))) |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 2376 | generic_make_request(bio); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 2377 | |
| 2378 | spin_lock_irq(q->queue_lock); |
| 2379 | } |
| 2380 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2381 | int blk_throtl_init(struct request_queue *q) |
| 2382 | { |
| 2383 | struct throtl_data *td; |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 2384 | int ret; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2385 | |
| 2386 | td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node); |
| 2387 | if (!td) |
| 2388 | return -ENOMEM; |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2389 | td->latency_buckets = __alloc_percpu(sizeof(struct latency_bucket) * |
| 2390 | LATENCY_BUCKET_SIZE, __alignof__(u64)); |
| 2391 | if (!td->latency_buckets) { |
| 2392 | kfree(td); |
| 2393 | return -ENOMEM; |
| 2394 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2395 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 2396 | INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 2397 | throtl_service_queue_init(&td->service_queue); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2398 | |
Tejun Heo | cd1604f | 2012-03-05 13:15:06 -0800 | [diff] [blame] | 2399 | q->td = td; |
Vivek Goyal | 29b1258 | 2011-05-19 15:38:24 -0400 | [diff] [blame] | 2400 | td->queue = q; |
Vivek Goyal | 02977e4 | 2010-10-01 14:49:48 +0200 | [diff] [blame] | 2401 | |
Shaohua Li | 9f626e3 | 2017-03-27 10:51:30 -0700 | [diff] [blame] | 2402 | td->limit_valid[LIMIT_MAX] = true; |
Shaohua Li | cd5ab1b | 2017-03-27 10:51:32 -0700 | [diff] [blame] | 2403 | td->limit_index = LIMIT_MAX; |
Shaohua Li | 3f0abd8 | 2017-03-27 10:51:35 -0700 | [diff] [blame] | 2404 | td->low_upgrade_time = jiffies; |
| 2405 | td->low_downgrade_time = jiffies; |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2406 | |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 2407 | /* activate policy */ |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 2408 | ret = blkcg_activate_policy(q, &blkcg_policy_throtl); |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2409 | if (ret) { |
| 2410 | free_percpu(td->latency_buckets); |
Vivek Goyal | 29b1258 | 2011-05-19 15:38:24 -0400 | [diff] [blame] | 2411 | kfree(td); |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2412 | } |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 2413 | return ret; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2414 | } |
| 2415 | |
| 2416 | void blk_throtl_exit(struct request_queue *q) |
| 2417 | { |
Tejun Heo | c875f4d | 2012-03-05 13:15:22 -0800 | [diff] [blame] | 2418 | BUG_ON(!q->td); |
Vivek Goyal | da52777 | 2011-03-02 19:05:33 -0500 | [diff] [blame] | 2419 | throtl_shutdown_wq(q); |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 2420 | blkcg_deactivate_policy(q, &blkcg_policy_throtl); |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2421 | free_percpu(q->td->latency_buckets); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 2422 | kfree(q->td); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2423 | } |
| 2424 | |
Shaohua Li | d61fcfa | 2017-03-27 10:51:38 -0700 | [diff] [blame] | 2425 | void blk_throtl_register_queue(struct request_queue *q) |
| 2426 | { |
| 2427 | struct throtl_data *td; |
Shaohua Li | 6679a90 | 2017-06-06 12:40:43 -0700 | [diff] [blame] | 2428 | int i; |
Shaohua Li | d61fcfa | 2017-03-27 10:51:38 -0700 | [diff] [blame] | 2429 | |
| 2430 | td = q->td; |
| 2431 | BUG_ON(!td); |
| 2432 | |
Shaohua Li | 6679a90 | 2017-06-06 12:40:43 -0700 | [diff] [blame] | 2433 | if (blk_queue_nonrot(q)) { |
Shaohua Li | d61fcfa | 2017-03-27 10:51:38 -0700 | [diff] [blame] | 2434 | td->throtl_slice = DFL_THROTL_SLICE_SSD; |
Shaohua Li | 6679a90 | 2017-06-06 12:40:43 -0700 | [diff] [blame] | 2435 | td->filtered_latency = LATENCY_FILTERED_SSD; |
| 2436 | } else { |
Shaohua Li | d61fcfa | 2017-03-27 10:51:38 -0700 | [diff] [blame] | 2437 | td->throtl_slice = DFL_THROTL_SLICE_HD; |
Shaohua Li | 6679a90 | 2017-06-06 12:40:43 -0700 | [diff] [blame] | 2438 | td->filtered_latency = LATENCY_FILTERED_HD; |
| 2439 | for (i = 0; i < LATENCY_BUCKET_SIZE; i++) |
| 2440 | td->avg_buckets[i].latency = DFL_HD_BASELINE_LATENCY; |
| 2441 | } |
Shaohua Li | d61fcfa | 2017-03-27 10:51:38 -0700 | [diff] [blame] | 2442 | #ifndef CONFIG_BLK_DEV_THROTTLING_LOW |
| 2443 | /* if no low limit, use previous default */ |
| 2444 | td->throtl_slice = DFL_THROTL_SLICE_HD; |
| 2445 | #endif |
Shaohua Li | 9e234ee | 2017-03-27 10:51:41 -0700 | [diff] [blame] | 2446 | |
Shaohua Li | b9147dd | 2017-03-27 15:19:42 -0700 | [diff] [blame] | 2447 | td->track_bio_latency = !q->mq_ops && !q->request_fn; |
| 2448 | if (!td->track_bio_latency) |
| 2449 | blk_stat_enable_accounting(q); |
Shaohua Li | d61fcfa | 2017-03-27 10:51:38 -0700 | [diff] [blame] | 2450 | } |
| 2451 | |
Shaohua Li | 297e3d8 | 2017-03-27 10:51:37 -0700 | [diff] [blame] | 2452 | #ifdef CONFIG_BLK_DEV_THROTTLING_LOW |
| 2453 | ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page) |
| 2454 | { |
| 2455 | if (!q->td) |
| 2456 | return -EINVAL; |
| 2457 | return sprintf(page, "%u\n", jiffies_to_msecs(q->td->throtl_slice)); |
| 2458 | } |
| 2459 | |
| 2460 | ssize_t blk_throtl_sample_time_store(struct request_queue *q, |
| 2461 | const char *page, size_t count) |
| 2462 | { |
| 2463 | unsigned long v; |
| 2464 | unsigned long t; |
| 2465 | |
| 2466 | if (!q->td) |
| 2467 | return -EINVAL; |
| 2468 | if (kstrtoul(page, 10, &v)) |
| 2469 | return -EINVAL; |
| 2470 | t = msecs_to_jiffies(v); |
| 2471 | if (t == 0 || t > MAX_THROTL_SLICE) |
| 2472 | return -EINVAL; |
| 2473 | q->td->throtl_slice = t; |
| 2474 | return count; |
| 2475 | } |
| 2476 | #endif |
| 2477 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2478 | static int __init throtl_init(void) |
| 2479 | { |
Vivek Goyal | 450adcb | 2011-03-01 13:40:54 -0500 | [diff] [blame] | 2480 | kthrotld_workqueue = alloc_workqueue("kthrotld", WQ_MEM_RECLAIM, 0); |
| 2481 | if (!kthrotld_workqueue) |
| 2482 | panic("Failed to create kthrotld\n"); |
| 2483 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 2484 | return blkcg_policy_register(&blkcg_policy_throtl); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 2485 | } |
| 2486 | |
| 2487 | module_init(throtl_init); |