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 | |
| 21 | /* Throttling is performed over 100ms slice and after that slice is renewed */ |
| 22 | static unsigned long throtl_slice = HZ/10; /* 100 ms */ |
| 23 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 24 | static struct blkcg_policy blkcg_policy_throtl; |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 25 | |
Vivek Goyal | 450adcb | 2011-03-01 13:40:54 -0500 | [diff] [blame] | 26 | /* A workqueue to queue throttle related work */ |
| 27 | static struct workqueue_struct *kthrotld_workqueue; |
Vivek Goyal | 450adcb | 2011-03-01 13:40:54 -0500 | [diff] [blame] | 28 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 29 | /* |
| 30 | * To implement hierarchical throttling, throtl_grps form a tree and bios |
| 31 | * are dispatched upwards level by level until they reach the top and get |
| 32 | * issued. When dispatching bios from the children and local group at each |
| 33 | * level, if the bios are dispatched into a single bio_list, there's a risk |
| 34 | * of a local or child group which can queue many bios at once filling up |
| 35 | * the list starving others. |
| 36 | * |
| 37 | * To avoid such starvation, dispatched bios are queued separately |
| 38 | * according to where they came from. When they are again dispatched to |
| 39 | * the parent, they're popped in round-robin order so that no single source |
| 40 | * hogs the dispatch window. |
| 41 | * |
| 42 | * throtl_qnode is used to keep the queued bios separated by their sources. |
| 43 | * Bios are queued to throtl_qnode which in turn is queued to |
| 44 | * throtl_service_queue and then dispatched in round-robin order. |
| 45 | * |
| 46 | * It's also used to track the reference counts on blkg's. A qnode always |
| 47 | * belongs to a throtl_grp and gets queued on itself or the parent, so |
| 48 | * incrementing the reference of the associated throtl_grp when a qnode is |
| 49 | * queued and decrementing when dequeued is enough to keep the whole blkg |
| 50 | * tree pinned while bios are in flight. |
| 51 | */ |
| 52 | struct throtl_qnode { |
| 53 | struct list_head node; /* service_queue->queued[] */ |
| 54 | struct bio_list bios; /* queued bios */ |
| 55 | struct throtl_grp *tg; /* tg this qnode belongs to */ |
| 56 | }; |
| 57 | |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 58 | struct throtl_service_queue { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 59 | struct throtl_service_queue *parent_sq; /* the parent service_queue */ |
| 60 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 61 | /* |
| 62 | * Bios queued directly to this service_queue or dispatched from |
| 63 | * children throtl_grp's. |
| 64 | */ |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 65 | struct list_head queued[2]; /* throtl_qnode [READ/WRITE] */ |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 66 | unsigned int nr_queued[2]; /* number of queued bios */ |
| 67 | |
| 68 | /* |
| 69 | * RB tree of active children throtl_grp's, which are sorted by |
| 70 | * their ->disptime. |
| 71 | */ |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 72 | struct rb_root pending_tree; /* RB tree of active tgs */ |
| 73 | struct rb_node *first_pending; /* first node in the tree */ |
| 74 | unsigned int nr_pending; /* # queued in the tree */ |
| 75 | unsigned long first_pending_disptime; /* disptime of the first tg */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 76 | struct timer_list pending_timer; /* fires on first_pending_disptime */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 77 | }; |
| 78 | |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 79 | enum tg_state_flags { |
| 80 | THROTL_TG_PENDING = 1 << 0, /* on parent's pending tree */ |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 81 | THROTL_TG_WAS_EMPTY = 1 << 1, /* bio_lists[] became non-empty */ |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 82 | }; |
| 83 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 84 | #define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node) |
| 85 | |
| 86 | struct throtl_grp { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 87 | /* must be the first member */ |
| 88 | struct blkg_policy_data pd; |
| 89 | |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 90 | /* active throtl group service_queue member */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 91 | struct rb_node rb_node; |
| 92 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 93 | /* throtl_data this group belongs to */ |
| 94 | struct throtl_data *td; |
| 95 | |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 96 | /* this group's service queue */ |
| 97 | struct throtl_service_queue service_queue; |
| 98 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 99 | /* |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 100 | * qnode_on_self is used when bios are directly queued to this |
| 101 | * throtl_grp so that local bios compete fairly with bios |
| 102 | * dispatched from children. qnode_on_parent is used when bios are |
| 103 | * dispatched from this throtl_grp into its parent and will compete |
| 104 | * with the sibling qnode_on_parents and the parent's |
| 105 | * qnode_on_self. |
| 106 | */ |
| 107 | struct throtl_qnode qnode_on_self[2]; |
| 108 | struct throtl_qnode qnode_on_parent[2]; |
| 109 | |
| 110 | /* |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 111 | * Dispatch time in jiffies. This is the estimated time when group |
| 112 | * will unthrottle and is ready to dispatch more bio. It is used as |
| 113 | * key to sort active groups in service tree. |
| 114 | */ |
| 115 | unsigned long disptime; |
| 116 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 117 | unsigned int flags; |
| 118 | |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 119 | /* are there any throtl rules between this group and td? */ |
| 120 | bool has_rules[2]; |
| 121 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 122 | /* bytes per second rate limits */ |
| 123 | uint64_t bps[2]; |
| 124 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 125 | /* IOPS limits */ |
| 126 | unsigned int iops[2]; |
| 127 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 128 | /* Number of bytes disptached in current slice */ |
| 129 | uint64_t bytes_disp[2]; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 130 | /* Number of bio's dispatched in current slice */ |
| 131 | unsigned int io_disp[2]; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 132 | |
| 133 | /* When did we start a new slice */ |
| 134 | unsigned long slice_start[2]; |
| 135 | unsigned long slice_end[2]; |
| 136 | }; |
| 137 | |
| 138 | struct throtl_data |
| 139 | { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 140 | /* service tree for active throtl groups */ |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 141 | struct throtl_service_queue service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 142 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 143 | struct request_queue *queue; |
| 144 | |
| 145 | /* Total Number of queued bios on READ and WRITE lists */ |
| 146 | unsigned int nr_queued[2]; |
| 147 | |
| 148 | /* |
Vivek Goyal | 02977e4 | 2010-10-01 14:49:48 +0200 | [diff] [blame] | 149 | * number of total undestroyed groups |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 150 | */ |
| 151 | unsigned int nr_undestroyed_grps; |
| 152 | |
| 153 | /* Work for dispatching throttled bios */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 154 | struct work_struct dispatch_work; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 155 | }; |
| 156 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 157 | static void throtl_pending_timer_fn(unsigned long arg); |
| 158 | |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 159 | static inline struct throtl_grp *pd_to_tg(struct blkg_policy_data *pd) |
| 160 | { |
| 161 | return pd ? container_of(pd, struct throtl_grp, pd) : NULL; |
| 162 | } |
| 163 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 164 | static inline struct throtl_grp *blkg_to_tg(struct blkcg_gq *blkg) |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 165 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 166 | return pd_to_tg(blkg_to_pd(blkg, &blkcg_policy_throtl)); |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 167 | } |
| 168 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 169 | static inline struct blkcg_gq *tg_to_blkg(struct throtl_grp *tg) |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 170 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 171 | return pd_to_blkg(&tg->pd); |
Tejun Heo | 0381411 | 2012-03-05 13:15:14 -0800 | [diff] [blame] | 172 | } |
| 173 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 174 | /** |
| 175 | * sq_to_tg - return the throl_grp the specified service queue belongs to |
| 176 | * @sq: the throtl_service_queue of interest |
| 177 | * |
| 178 | * Return the throtl_grp @sq belongs to. If @sq is the top-level one |
| 179 | * embedded in throtl_data, %NULL is returned. |
| 180 | */ |
| 181 | static struct throtl_grp *sq_to_tg(struct throtl_service_queue *sq) |
| 182 | { |
| 183 | if (sq && sq->parent_sq) |
| 184 | return container_of(sq, struct throtl_grp, service_queue); |
| 185 | else |
| 186 | return NULL; |
| 187 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 188 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 189 | /** |
| 190 | * sq_to_td - return throtl_data the specified service queue belongs to |
| 191 | * @sq: the throtl_service_queue of interest |
| 192 | * |
| 193 | * A service_queue can be embeded in either a throtl_grp or throtl_data. |
| 194 | * Determine the associated throtl_data accordingly and return it. |
| 195 | */ |
| 196 | static struct throtl_data *sq_to_td(struct throtl_service_queue *sq) |
| 197 | { |
| 198 | struct throtl_grp *tg = sq_to_tg(sq); |
| 199 | |
| 200 | if (tg) |
| 201 | return tg->td; |
| 202 | else |
| 203 | return container_of(sq, struct throtl_data, service_queue); |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * throtl_log - log debug message via blktrace |
| 208 | * @sq: the service_queue being reported |
| 209 | * @fmt: printf format string |
| 210 | * @args: printf args |
| 211 | * |
| 212 | * The messages are prefixed with "throtl BLKG_NAME" if @sq belongs to a |
| 213 | * throtl_grp; otherwise, just "throtl". |
| 214 | * |
| 215 | * TODO: this should be made a function and name formatting should happen |
| 216 | * after testing whether blktrace is enabled. |
| 217 | */ |
| 218 | #define throtl_log(sq, fmt, args...) do { \ |
| 219 | struct throtl_grp *__tg = sq_to_tg((sq)); \ |
| 220 | struct throtl_data *__td = sq_to_td((sq)); \ |
| 221 | \ |
| 222 | (void)__td; \ |
| 223 | if ((__tg)) { \ |
| 224 | char __pbuf[128]; \ |
| 225 | \ |
| 226 | blkg_path(tg_to_blkg(__tg), __pbuf, sizeof(__pbuf)); \ |
| 227 | blk_add_trace_msg(__td->queue, "throtl %s " fmt, __pbuf, ##args); \ |
| 228 | } else { \ |
| 229 | blk_add_trace_msg(__td->queue, "throtl " fmt, ##args); \ |
| 230 | } \ |
| 231 | } while (0) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 232 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 233 | static void throtl_qnode_init(struct throtl_qnode *qn, struct throtl_grp *tg) |
| 234 | { |
| 235 | INIT_LIST_HEAD(&qn->node); |
| 236 | bio_list_init(&qn->bios); |
| 237 | qn->tg = tg; |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * throtl_qnode_add_bio - add a bio to a throtl_qnode and activate it |
| 242 | * @bio: bio being added |
| 243 | * @qn: qnode to add bio to |
| 244 | * @queued: the service_queue->queued[] list @qn belongs to |
| 245 | * |
| 246 | * Add @bio to @qn and put @qn on @queued if it's not already on. |
| 247 | * @qn->tg's reference count is bumped when @qn is activated. See the |
| 248 | * comment on top of throtl_qnode definition for details. |
| 249 | */ |
| 250 | static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn, |
| 251 | struct list_head *queued) |
| 252 | { |
| 253 | bio_list_add(&qn->bios, bio); |
| 254 | if (list_empty(&qn->node)) { |
| 255 | list_add_tail(&qn->node, queued); |
| 256 | blkg_get(tg_to_blkg(qn->tg)); |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * throtl_peek_queued - peek the first bio on a qnode list |
| 262 | * @queued: the qnode list to peek |
| 263 | */ |
| 264 | static struct bio *throtl_peek_queued(struct list_head *queued) |
| 265 | { |
| 266 | struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); |
| 267 | struct bio *bio; |
| 268 | |
| 269 | if (list_empty(queued)) |
| 270 | return NULL; |
| 271 | |
| 272 | bio = bio_list_peek(&qn->bios); |
| 273 | WARN_ON_ONCE(!bio); |
| 274 | return bio; |
| 275 | } |
| 276 | |
| 277 | /** |
| 278 | * throtl_pop_queued - pop the first bio form a qnode list |
| 279 | * @queued: the qnode list to pop a bio from |
| 280 | * @tg_to_put: optional out argument for throtl_grp to put |
| 281 | * |
| 282 | * Pop the first bio from the qnode list @queued. After popping, the first |
| 283 | * qnode is removed from @queued if empty or moved to the end of @queued so |
| 284 | * that the popping order is round-robin. |
| 285 | * |
| 286 | * When the first qnode is removed, its associated throtl_grp should be put |
| 287 | * too. If @tg_to_put is NULL, this function automatically puts it; |
| 288 | * otherwise, *@tg_to_put is set to the throtl_grp to put and the caller is |
| 289 | * responsible for putting it. |
| 290 | */ |
| 291 | static struct bio *throtl_pop_queued(struct list_head *queued, |
| 292 | struct throtl_grp **tg_to_put) |
| 293 | { |
| 294 | struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); |
| 295 | struct bio *bio; |
| 296 | |
| 297 | if (list_empty(queued)) |
| 298 | return NULL; |
| 299 | |
| 300 | bio = bio_list_pop(&qn->bios); |
| 301 | WARN_ON_ONCE(!bio); |
| 302 | |
| 303 | if (bio_list_empty(&qn->bios)) { |
| 304 | list_del_init(&qn->node); |
| 305 | if (tg_to_put) |
| 306 | *tg_to_put = qn->tg; |
| 307 | else |
| 308 | blkg_put(tg_to_blkg(qn->tg)); |
| 309 | } else { |
| 310 | list_move_tail(&qn->node, queued); |
| 311 | } |
| 312 | |
| 313 | return bio; |
| 314 | } |
| 315 | |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 316 | /* init a service_queue, assumes the caller zeroed it */ |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 317 | static void throtl_service_queue_init(struct throtl_service_queue *sq) |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 318 | { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 319 | INIT_LIST_HEAD(&sq->queued[0]); |
| 320 | INIT_LIST_HEAD(&sq->queued[1]); |
Tejun Heo | 49a2f1e | 2013-05-14 13:52:34 -0700 | [diff] [blame] | 321 | sq->pending_tree = RB_ROOT; |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 322 | setup_timer(&sq->pending_timer, throtl_pending_timer_fn, |
| 323 | (unsigned long)sq); |
| 324 | } |
| 325 | |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 326 | static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node) |
| 327 | { |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 328 | struct throtl_grp *tg; |
Tejun Heo | 24bdb8e | 2015-08-18 14:55:22 -0700 | [diff] [blame] | 329 | int rw; |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 330 | |
| 331 | tg = kzalloc_node(sizeof(*tg), gfp, node); |
| 332 | if (!tg) |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 333 | return NULL; |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 334 | |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 335 | throtl_service_queue_init(&tg->service_queue); |
| 336 | |
| 337 | for (rw = READ; rw <= WRITE; rw++) { |
| 338 | throtl_qnode_init(&tg->qnode_on_self[rw], tg); |
| 339 | throtl_qnode_init(&tg->qnode_on_parent[rw], tg); |
| 340 | } |
| 341 | |
| 342 | RB_CLEAR_NODE(&tg->rb_node); |
| 343 | tg->bps[READ] = -1; |
| 344 | tg->bps[WRITE] = -1; |
| 345 | tg->iops[READ] = -1; |
| 346 | tg->iops[WRITE] = -1; |
| 347 | |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 348 | return &tg->pd; |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 349 | } |
| 350 | |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 351 | static void throtl_pd_init(struct blkg_policy_data *pd) |
Vivek Goyal | a29a171 | 2011-05-19 15:38:19 -0400 | [diff] [blame] | 352 | { |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 353 | struct throtl_grp *tg = pd_to_tg(pd); |
| 354 | struct blkcg_gq *blkg = tg_to_blkg(tg); |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 355 | struct throtl_data *td = blkg->q->td; |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 356 | struct throtl_service_queue *sq = &tg->service_queue; |
Tejun Heo | cd1604f | 2012-03-05 13:15:06 -0800 | [diff] [blame] | 357 | |
Tejun Heo | 9138125 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 358 | /* |
Tejun Heo | aa6ec29 | 2014-07-09 10:08:08 -0400 | [diff] [blame] | 359 | * If on the default hierarchy, we switch to properly hierarchical |
Tejun Heo | 9138125 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 360 | * behavior where limits on a given throtl_grp are applied to the |
| 361 | * whole subtree rather than just the group itself. e.g. If 16M |
| 362 | * read_bps limit is set on the root group, the whole system can't |
| 363 | * exceed 16M for the device. |
| 364 | * |
Tejun Heo | aa6ec29 | 2014-07-09 10:08:08 -0400 | [diff] [blame] | 365 | * If not on the default hierarchy, the broken flat hierarchy |
Tejun Heo | 9138125 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 366 | * behavior is retained where all throtl_grps are treated as if |
| 367 | * they're all separate root groups right below throtl_data. |
| 368 | * Limits of a group don't interact with limits of other groups |
| 369 | * regardless of the position of the group in the hierarchy. |
| 370 | */ |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 371 | sq->parent_sq = &td->service_queue; |
Tejun Heo | aa6ec29 | 2014-07-09 10:08:08 -0400 | [diff] [blame] | 372 | if (cgroup_on_dfl(blkg->blkcg->css.cgroup) && blkg->parent) |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 373 | sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 374 | tg->td = td; |
Tejun Heo | 8a3d261 | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 375 | } |
| 376 | |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 377 | /* |
| 378 | * Set has_rules[] if @tg or any of its parents have limits configured. |
| 379 | * This doesn't require walking up to the top of the hierarchy as the |
| 380 | * parent's has_rules[] is guaranteed to be correct. |
| 381 | */ |
| 382 | static void tg_update_has_rules(struct throtl_grp *tg) |
| 383 | { |
| 384 | struct throtl_grp *parent_tg = sq_to_tg(tg->service_queue.parent_sq); |
| 385 | int rw; |
| 386 | |
| 387 | for (rw = READ; rw <= WRITE; rw++) |
| 388 | tg->has_rules[rw] = (parent_tg && parent_tg->has_rules[rw]) || |
| 389 | (tg->bps[rw] != -1 || tg->iops[rw] != -1); |
| 390 | } |
| 391 | |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 392 | static void throtl_pd_online(struct blkg_policy_data *pd) |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 393 | { |
| 394 | /* |
| 395 | * We don't want new groups to escape the limits of its ancestors. |
| 396 | * Update has_rules[] after a new group is brought online. |
| 397 | */ |
Tejun Heo | a9520cd | 2015-08-18 14:55:14 -0700 | [diff] [blame] | 398 | tg_update_has_rules(pd_to_tg(pd)); |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 399 | } |
| 400 | |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 401 | static void throtl_pd_free(struct blkg_policy_data *pd) |
| 402 | { |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 403 | struct throtl_grp *tg = pd_to_tg(pd); |
| 404 | |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 405 | del_timer_sync(&tg->service_queue.pending_timer); |
Tejun Heo | 4fb7203 | 2015-08-18 14:55:12 -0700 | [diff] [blame] | 406 | kfree(tg); |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 407 | } |
| 408 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 409 | static struct throtl_grp * |
| 410 | throtl_rb_first(struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 411 | { |
| 412 | /* Service tree is empty */ |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 413 | if (!parent_sq->nr_pending) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 414 | return NULL; |
| 415 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 416 | if (!parent_sq->first_pending) |
| 417 | parent_sq->first_pending = rb_first(&parent_sq->pending_tree); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 418 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 419 | if (parent_sq->first_pending) |
| 420 | return rb_entry_tg(parent_sq->first_pending); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 421 | |
| 422 | return NULL; |
| 423 | } |
| 424 | |
| 425 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 426 | { |
| 427 | rb_erase(n, root); |
| 428 | RB_CLEAR_NODE(n); |
| 429 | } |
| 430 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 431 | static void throtl_rb_erase(struct rb_node *n, |
| 432 | struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 433 | { |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 434 | if (parent_sq->first_pending == n) |
| 435 | parent_sq->first_pending = NULL; |
| 436 | rb_erase_init(n, &parent_sq->pending_tree); |
| 437 | --parent_sq->nr_pending; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 438 | } |
| 439 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 440 | static void update_min_dispatch_time(struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 441 | { |
| 442 | struct throtl_grp *tg; |
| 443 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 444 | tg = throtl_rb_first(parent_sq); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 445 | if (!tg) |
| 446 | return; |
| 447 | |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 448 | parent_sq->first_pending_disptime = tg->disptime; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 449 | } |
| 450 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 451 | static void tg_service_queue_add(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 452 | { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 453 | struct throtl_service_queue *parent_sq = tg->service_queue.parent_sq; |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 454 | struct rb_node **node = &parent_sq->pending_tree.rb_node; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 455 | struct rb_node *parent = NULL; |
| 456 | struct throtl_grp *__tg; |
| 457 | unsigned long key = tg->disptime; |
| 458 | int left = 1; |
| 459 | |
| 460 | while (*node != NULL) { |
| 461 | parent = *node; |
| 462 | __tg = rb_entry_tg(parent); |
| 463 | |
| 464 | if (time_before(key, __tg->disptime)) |
| 465 | node = &parent->rb_left; |
| 466 | else { |
| 467 | node = &parent->rb_right; |
| 468 | left = 0; |
| 469 | } |
| 470 | } |
| 471 | |
| 472 | if (left) |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 473 | parent_sq->first_pending = &tg->rb_node; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 474 | |
| 475 | rb_link_node(&tg->rb_node, parent, node); |
Tejun Heo | 0049af7 | 2013-05-14 13:52:33 -0700 | [diff] [blame] | 476 | rb_insert_color(&tg->rb_node, &parent_sq->pending_tree); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 477 | } |
| 478 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 479 | static void __throtl_enqueue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 480 | { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 481 | tg_service_queue_add(tg); |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 482 | tg->flags |= THROTL_TG_PENDING; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 483 | tg->service_queue.parent_sq->nr_pending++; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 484 | } |
| 485 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 486 | static void throtl_enqueue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 487 | { |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 488 | if (!(tg->flags & THROTL_TG_PENDING)) |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 489 | __throtl_enqueue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 490 | } |
| 491 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 492 | static void __throtl_dequeue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 493 | { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 494 | throtl_rb_erase(&tg->rb_node, tg->service_queue.parent_sq); |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 495 | tg->flags &= ~THROTL_TG_PENDING; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 496 | } |
| 497 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 498 | static void throtl_dequeue_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 499 | { |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 500 | if (tg->flags & THROTL_TG_PENDING) |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 501 | __throtl_dequeue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 502 | } |
| 503 | |
Tejun Heo | a9131a2 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 504 | /* Call with queue lock held */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 505 | static void throtl_schedule_pending_timer(struct throtl_service_queue *sq, |
| 506 | unsigned long expires) |
Tejun Heo | a9131a2 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 507 | { |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 508 | mod_timer(&sq->pending_timer, expires); |
| 509 | throtl_log(sq, "schedule timer. delay=%lu jiffies=%lu", |
| 510 | expires - jiffies, jiffies); |
Tejun Heo | a9131a2 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 511 | } |
| 512 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 513 | /** |
| 514 | * throtl_schedule_next_dispatch - schedule the next dispatch cycle |
| 515 | * @sq: the service_queue to schedule dispatch for |
| 516 | * @force: force scheduling |
| 517 | * |
| 518 | * Arm @sq->pending_timer so that the next dispatch cycle starts on the |
| 519 | * dispatch time of the first pending child. Returns %true if either timer |
| 520 | * is armed or there's no pending child left. %false if the current |
| 521 | * dispatch window is still open and the caller should continue |
| 522 | * dispatching. |
| 523 | * |
| 524 | * If @force is %true, the dispatch timer is always scheduled and this |
| 525 | * function is guaranteed to return %true. This is to be used when the |
| 526 | * caller can't dispatch itself and needs to invoke pending_timer |
| 527 | * unconditionally. Note that forced scheduling is likely to induce short |
| 528 | * delay before dispatch starts even if @sq->first_pending_disptime is not |
| 529 | * in the future and thus shouldn't be used in hot paths. |
| 530 | */ |
| 531 | static bool throtl_schedule_next_dispatch(struct throtl_service_queue *sq, |
| 532 | bool force) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 533 | { |
Tejun Heo | 6a52560 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 534 | /* any pending children left? */ |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 535 | if (!sq->nr_pending) |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 536 | return true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 537 | |
Tejun Heo | c9e0332 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 538 | update_min_dispatch_time(sq); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 539 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 540 | /* is the next dispatch time in the future? */ |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 541 | if (force || time_after(sq->first_pending_disptime, jiffies)) { |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 542 | throtl_schedule_pending_timer(sq, sq->first_pending_disptime); |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 543 | return true; |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 544 | } |
| 545 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 546 | /* tell the caller to continue dispatching */ |
| 547 | return false; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 548 | } |
| 549 | |
Vivek Goyal | 32ee5bc | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 550 | static inline void throtl_start_new_slice_with_credit(struct throtl_grp *tg, |
| 551 | bool rw, unsigned long start) |
| 552 | { |
| 553 | tg->bytes_disp[rw] = 0; |
| 554 | tg->io_disp[rw] = 0; |
| 555 | |
| 556 | /* |
| 557 | * Previous slice has expired. We must have trimmed it after last |
| 558 | * bio dispatch. That means since start of last slice, we never used |
| 559 | * that bandwidth. Do try to make use of that bandwidth while giving |
| 560 | * credit. |
| 561 | */ |
| 562 | if (time_after_eq(start, tg->slice_start[rw])) |
| 563 | tg->slice_start[rw] = start; |
| 564 | |
| 565 | tg->slice_end[rw] = jiffies + throtl_slice; |
| 566 | throtl_log(&tg->service_queue, |
| 567 | "[%c] new slice with credit start=%lu end=%lu jiffies=%lu", |
| 568 | rw == READ ? 'R' : 'W', tg->slice_start[rw], |
| 569 | tg->slice_end[rw], jiffies); |
| 570 | } |
| 571 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 572 | 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] | 573 | { |
| 574 | tg->bytes_disp[rw] = 0; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 575 | tg->io_disp[rw] = 0; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 576 | tg->slice_start[rw] = jiffies; |
| 577 | tg->slice_end[rw] = jiffies + throtl_slice; |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 578 | throtl_log(&tg->service_queue, |
| 579 | "[%c] new slice start=%lu end=%lu jiffies=%lu", |
| 580 | rw == READ ? 'R' : 'W', tg->slice_start[rw], |
| 581 | tg->slice_end[rw], jiffies); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 582 | } |
| 583 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 584 | static inline void throtl_set_slice_end(struct throtl_grp *tg, bool rw, |
| 585 | unsigned long jiffy_end) |
Vivek Goyal | d1ae8ff | 2010-12-01 19:34:46 +0100 | [diff] [blame] | 586 | { |
| 587 | tg->slice_end[rw] = roundup(jiffy_end, throtl_slice); |
| 588 | } |
| 589 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 590 | static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw, |
| 591 | unsigned long jiffy_end) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 592 | { |
| 593 | tg->slice_end[rw] = roundup(jiffy_end, throtl_slice); |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 594 | throtl_log(&tg->service_queue, |
| 595 | "[%c] extend slice start=%lu end=%lu jiffies=%lu", |
| 596 | rw == READ ? 'R' : 'W', tg->slice_start[rw], |
| 597 | tg->slice_end[rw], jiffies); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 598 | } |
| 599 | |
| 600 | /* Determine if previously allocated or extended slice is complete or not */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 601 | static bool throtl_slice_used(struct throtl_grp *tg, bool rw) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 602 | { |
| 603 | 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] | 604 | return false; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 605 | |
| 606 | return 1; |
| 607 | } |
| 608 | |
| 609 | /* Trim the used slices and adjust slice start accordingly */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 610 | static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 611 | { |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 612 | unsigned long nr_slices, time_elapsed, io_trim; |
| 613 | u64 bytes_trim, tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 614 | |
| 615 | BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw])); |
| 616 | |
| 617 | /* |
| 618 | * If bps are unlimited (-1), then time slice don't get |
| 619 | * renewed. Don't try to trim the slice if slice is used. A new |
| 620 | * slice will start when appropriate. |
| 621 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 622 | if (throtl_slice_used(tg, rw)) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 623 | return; |
| 624 | |
Vivek Goyal | d1ae8ff | 2010-12-01 19:34:46 +0100 | [diff] [blame] | 625 | /* |
| 626 | * A bio has been dispatched. Also adjust slice_end. It might happen |
| 627 | * that initially cgroup limit was very low resulting in high |
| 628 | * slice_end, but later limit was bumped up and bio was dispached |
| 629 | * sooner, then we need to reduce slice_end. A high bogus slice_end |
| 630 | * is bad because it does not allow new slice to start. |
| 631 | */ |
| 632 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 633 | throtl_set_slice_end(tg, rw, jiffies + throtl_slice); |
Vivek Goyal | d1ae8ff | 2010-12-01 19:34:46 +0100 | [diff] [blame] | 634 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 635 | time_elapsed = jiffies - tg->slice_start[rw]; |
| 636 | |
| 637 | nr_slices = time_elapsed / throtl_slice; |
| 638 | |
| 639 | if (!nr_slices) |
| 640 | return; |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 641 | tmp = tg->bps[rw] * throtl_slice * nr_slices; |
| 642 | do_div(tmp, HZ); |
| 643 | bytes_trim = tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 644 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 645 | io_trim = (tg->iops[rw] * throtl_slice * nr_slices)/HZ; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 646 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 647 | if (!bytes_trim && !io_trim) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 648 | return; |
| 649 | |
| 650 | if (tg->bytes_disp[rw] >= bytes_trim) |
| 651 | tg->bytes_disp[rw] -= bytes_trim; |
| 652 | else |
| 653 | tg->bytes_disp[rw] = 0; |
| 654 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 655 | if (tg->io_disp[rw] >= io_trim) |
| 656 | tg->io_disp[rw] -= io_trim; |
| 657 | else |
| 658 | tg->io_disp[rw] = 0; |
| 659 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 660 | tg->slice_start[rw] += nr_slices * throtl_slice; |
| 661 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 662 | throtl_log(&tg->service_queue, |
| 663 | "[%c] trim slice nr=%lu bytes=%llu io=%lu start=%lu end=%lu jiffies=%lu", |
| 664 | rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim, |
| 665 | tg->slice_start[rw], tg->slice_end[rw], jiffies); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 666 | } |
| 667 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 668 | static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, |
| 669 | unsigned long *wait) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 670 | { |
| 671 | bool rw = bio_data_dir(bio); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 672 | unsigned int io_allowed; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 673 | unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; |
Vivek Goyal | c49c06e | 2010-10-01 21:16:42 +0200 | [diff] [blame] | 674 | u64 tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 675 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 676 | jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw]; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 677 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 678 | /* Slice has just started. Consider one slice interval */ |
| 679 | if (!jiffy_elapsed) |
| 680 | jiffy_elapsed_rnd = throtl_slice; |
| 681 | |
| 682 | jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, throtl_slice); |
| 683 | |
Vivek Goyal | c49c06e | 2010-10-01 21:16:42 +0200 | [diff] [blame] | 684 | /* |
| 685 | * jiffy_elapsed_rnd should not be a big value as minimum iops can be |
| 686 | * 1 then at max jiffy elapsed should be equivalent of 1 second as we |
| 687 | * will allow dispatch after 1 second and after that slice should |
| 688 | * have been trimmed. |
| 689 | */ |
| 690 | |
| 691 | tmp = (u64)tg->iops[rw] * jiffy_elapsed_rnd; |
| 692 | do_div(tmp, HZ); |
| 693 | |
| 694 | if (tmp > UINT_MAX) |
| 695 | io_allowed = UINT_MAX; |
| 696 | else |
| 697 | io_allowed = tmp; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 698 | |
| 699 | if (tg->io_disp[rw] + 1 <= io_allowed) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 700 | if (wait) |
| 701 | *wait = 0; |
Fabian Frederick | 5cf8c22 | 2014-05-02 18:28:17 +0200 | [diff] [blame] | 702 | return true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 703 | } |
| 704 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 705 | /* Calc approx time to dispatch */ |
| 706 | jiffy_wait = ((tg->io_disp[rw] + 1) * HZ)/tg->iops[rw] + 1; |
| 707 | |
| 708 | if (jiffy_wait > jiffy_elapsed) |
| 709 | jiffy_wait = jiffy_wait - jiffy_elapsed; |
| 710 | else |
| 711 | jiffy_wait = 1; |
| 712 | |
| 713 | if (wait) |
| 714 | *wait = jiffy_wait; |
| 715 | return 0; |
| 716 | } |
| 717 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 718 | static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, |
| 719 | unsigned long *wait) |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 720 | { |
| 721 | bool rw = bio_data_dir(bio); |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 722 | u64 bytes_allowed, extra_bytes, tmp; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 723 | unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 724 | |
| 725 | jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw]; |
| 726 | |
| 727 | /* Slice has just started. Consider one slice interval */ |
| 728 | if (!jiffy_elapsed) |
| 729 | jiffy_elapsed_rnd = throtl_slice; |
| 730 | |
| 731 | jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, throtl_slice); |
| 732 | |
Vivek Goyal | 5e901a2 | 2010-10-01 21:16:38 +0200 | [diff] [blame] | 733 | tmp = tg->bps[rw] * jiffy_elapsed_rnd; |
| 734 | do_div(tmp, HZ); |
Vivek Goyal | 3aad5d3 | 2010-10-01 14:51:14 +0200 | [diff] [blame] | 735 | bytes_allowed = tmp; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 736 | |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 737 | if (tg->bytes_disp[rw] + bio->bi_iter.bi_size <= bytes_allowed) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 738 | if (wait) |
| 739 | *wait = 0; |
Fabian Frederick | 5cf8c22 | 2014-05-02 18:28:17 +0200 | [diff] [blame] | 740 | return true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 741 | } |
| 742 | |
| 743 | /* Calc approx time to dispatch */ |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 744 | extra_bytes = tg->bytes_disp[rw] + bio->bi_iter.bi_size - bytes_allowed; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 745 | jiffy_wait = div64_u64(extra_bytes * HZ, tg->bps[rw]); |
| 746 | |
| 747 | if (!jiffy_wait) |
| 748 | jiffy_wait = 1; |
| 749 | |
| 750 | /* |
| 751 | * This wait time is without taking into consideration the rounding |
| 752 | * up we did. Add that time also. |
| 753 | */ |
| 754 | jiffy_wait = jiffy_wait + (jiffy_elapsed_rnd - jiffy_elapsed); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 755 | if (wait) |
| 756 | *wait = jiffy_wait; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 757 | return 0; |
| 758 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 759 | |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 760 | /* |
| 761 | * Returns whether one can dispatch a bio or not. Also returns approx number |
| 762 | * of jiffies to wait before this bio is with-in IO rate and can be dispatched |
| 763 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 764 | static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, |
| 765 | unsigned long *wait) |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 766 | { |
| 767 | bool rw = bio_data_dir(bio); |
| 768 | unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0; |
| 769 | |
| 770 | /* |
| 771 | * Currently whole state machine of group depends on first bio |
| 772 | * queued in the group bio list. So one should not be calling |
| 773 | * this function with a different bio if there are other bios |
| 774 | * queued. |
| 775 | */ |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 776 | BUG_ON(tg->service_queue.nr_queued[rw] && |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 777 | bio != throtl_peek_queued(&tg->service_queue.queued[rw])); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 778 | |
| 779 | /* If tg->bps = -1, then BW is unlimited */ |
| 780 | if (tg->bps[rw] == -1 && tg->iops[rw] == -1) { |
| 781 | if (wait) |
| 782 | *wait = 0; |
Fabian Frederick | 5cf8c22 | 2014-05-02 18:28:17 +0200 | [diff] [blame] | 783 | return true; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 784 | } |
| 785 | |
| 786 | /* |
| 787 | * If previous slice expired, start a new one otherwise renew/extend |
| 788 | * existing slice to make sure it is at least throtl_slice interval |
| 789 | * long since now. |
| 790 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 791 | if (throtl_slice_used(tg, rw)) |
| 792 | throtl_start_new_slice(tg, rw); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 793 | else { |
| 794 | if (time_before(tg->slice_end[rw], jiffies + throtl_slice)) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 795 | throtl_extend_slice(tg, rw, jiffies + throtl_slice); |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 796 | } |
| 797 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 798 | if (tg_with_in_bps_limit(tg, bio, &bps_wait) && |
| 799 | tg_with_in_iops_limit(tg, bio, &iops_wait)) { |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 800 | if (wait) |
| 801 | *wait = 0; |
| 802 | return 1; |
| 803 | } |
| 804 | |
| 805 | max_wait = max(bps_wait, iops_wait); |
| 806 | |
| 807 | if (wait) |
| 808 | *wait = max_wait; |
| 809 | |
| 810 | if (time_before(tg->slice_end[rw], jiffies + max_wait)) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 811 | throtl_extend_slice(tg, rw, jiffies + max_wait); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 812 | |
| 813 | return 0; |
| 814 | } |
| 815 | |
| 816 | static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio) |
| 817 | { |
| 818 | bool rw = bio_data_dir(bio); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 819 | |
| 820 | /* Charge the bio to the group */ |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 821 | tg->bytes_disp[rw] += bio->bi_iter.bi_size; |
Vivek Goyal | 8e89d13 | 2010-09-15 17:06:37 -0400 | [diff] [blame] | 822 | tg->io_disp[rw]++; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 823 | |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 824 | /* |
| 825 | * REQ_THROTTLED is used to prevent the same bio to be throttled |
| 826 | * more than once as a throttled bio will go through blk-throtl the |
| 827 | * second time when it eventually gets issued. Set it when a bio |
| 828 | * is being charged to a tg. |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 829 | */ |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 830 | if (!(bio->bi_rw & REQ_THROTTLED)) |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 831 | bio->bi_rw |= REQ_THROTTLED; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 832 | } |
| 833 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 834 | /** |
| 835 | * throtl_add_bio_tg - add a bio to the specified throtl_grp |
| 836 | * @bio: bio to add |
| 837 | * @qn: qnode to use |
| 838 | * @tg: the target throtl_grp |
| 839 | * |
| 840 | * Add @bio to @tg's service_queue using @qn. If @qn is not specified, |
| 841 | * tg->qnode_on_self[] is used. |
| 842 | */ |
| 843 | static void throtl_add_bio_tg(struct bio *bio, struct throtl_qnode *qn, |
| 844 | struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 845 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 846 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 847 | bool rw = bio_data_dir(bio); |
| 848 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 849 | if (!qn) |
| 850 | qn = &tg->qnode_on_self[rw]; |
| 851 | |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 852 | /* |
| 853 | * If @tg doesn't currently have any bios queued in the same |
| 854 | * direction, queueing @bio can change when @tg should be |
| 855 | * dispatched. Mark that @tg was empty. This is automatically |
| 856 | * cleaered on the next tg_update_disptime(). |
| 857 | */ |
| 858 | if (!sq->nr_queued[rw]) |
| 859 | tg->flags |= THROTL_TG_WAS_EMPTY; |
| 860 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 861 | throtl_qnode_add_bio(bio, qn, &sq->queued[rw]); |
| 862 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 863 | sq->nr_queued[rw]++; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 864 | throtl_enqueue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 865 | } |
| 866 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 867 | static void tg_update_disptime(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 868 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 869 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 870 | unsigned long read_wait = -1, write_wait = -1, min_wait = -1, disptime; |
| 871 | struct bio *bio; |
| 872 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 873 | if ((bio = throtl_peek_queued(&sq->queued[READ]))) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 874 | tg_may_dispatch(tg, bio, &read_wait); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 875 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 876 | if ((bio = throtl_peek_queued(&sq->queued[WRITE]))) |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 877 | tg_may_dispatch(tg, bio, &write_wait); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 878 | |
| 879 | min_wait = min(read_wait, write_wait); |
| 880 | disptime = jiffies + min_wait; |
| 881 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 882 | /* Update dispatch time */ |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 883 | throtl_dequeue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 884 | tg->disptime = disptime; |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 885 | throtl_enqueue_tg(tg); |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 886 | |
| 887 | /* see throtl_add_bio_tg() */ |
| 888 | tg->flags &= ~THROTL_TG_WAS_EMPTY; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 889 | } |
| 890 | |
Vivek Goyal | 32ee5bc | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 891 | static void start_parent_slice_with_credit(struct throtl_grp *child_tg, |
| 892 | struct throtl_grp *parent_tg, bool rw) |
| 893 | { |
| 894 | if (throtl_slice_used(parent_tg, rw)) { |
| 895 | throtl_start_new_slice_with_credit(parent_tg, rw, |
| 896 | child_tg->slice_start[rw]); |
| 897 | } |
| 898 | |
| 899 | } |
| 900 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 901 | static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 902 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 903 | struct throtl_service_queue *sq = &tg->service_queue; |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 904 | struct throtl_service_queue *parent_sq = sq->parent_sq; |
| 905 | struct throtl_grp *parent_tg = sq_to_tg(parent_sq); |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 906 | struct throtl_grp *tg_to_put = NULL; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 907 | struct bio *bio; |
| 908 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 909 | /* |
| 910 | * @bio is being transferred from @tg to @parent_sq. Popping a bio |
| 911 | * from @tg may put its reference and @parent_sq might end up |
| 912 | * getting released prematurely. Remember the tg to put and put it |
| 913 | * after @bio is transferred to @parent_sq. |
| 914 | */ |
| 915 | bio = throtl_pop_queued(&sq->queued[rw], &tg_to_put); |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 916 | sq->nr_queued[rw]--; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 917 | |
| 918 | throtl_charge_bio(tg, bio); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 919 | |
| 920 | /* |
| 921 | * If our parent is another tg, we just need to transfer @bio to |
| 922 | * the parent using throtl_add_bio_tg(). If our parent is |
| 923 | * @td->service_queue, @bio is ready to be issued. Put it on its |
| 924 | * bio_lists[] and decrease total number queued. The caller is |
| 925 | * responsible for issuing these bios. |
| 926 | */ |
| 927 | if (parent_tg) { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 928 | throtl_add_bio_tg(bio, &tg->qnode_on_parent[rw], parent_tg); |
Vivek Goyal | 32ee5bc | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 929 | start_parent_slice_with_credit(tg, parent_tg, rw); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 930 | } else { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 931 | throtl_qnode_add_bio(bio, &tg->qnode_on_parent[rw], |
| 932 | &parent_sq->queued[rw]); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 933 | BUG_ON(tg->td->nr_queued[rw] <= 0); |
| 934 | tg->td->nr_queued[rw]--; |
| 935 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 936 | |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 937 | throtl_trim_slice(tg, rw); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 938 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 939 | if (tg_to_put) |
| 940 | blkg_put(tg_to_blkg(tg_to_put)); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 941 | } |
| 942 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 943 | static int throtl_dispatch_tg(struct throtl_grp *tg) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 944 | { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 945 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 946 | unsigned int nr_reads = 0, nr_writes = 0; |
| 947 | unsigned int max_nr_reads = throtl_grp_quantum*3/4; |
Vivek Goyal | c2f6805 | 2010-11-15 19:32:42 +0100 | [diff] [blame] | 948 | unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 949 | struct bio *bio; |
| 950 | |
| 951 | /* Try to dispatch 75% READS and 25% WRITES */ |
| 952 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 953 | while ((bio = throtl_peek_queued(&sq->queued[READ])) && |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 954 | tg_may_dispatch(tg, bio, NULL)) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 955 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 956 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 957 | nr_reads++; |
| 958 | |
| 959 | if (nr_reads >= max_nr_reads) |
| 960 | break; |
| 961 | } |
| 962 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 963 | while ((bio = throtl_peek_queued(&sq->queued[WRITE])) && |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 964 | tg_may_dispatch(tg, bio, NULL)) { |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 965 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 966 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 967 | nr_writes++; |
| 968 | |
| 969 | if (nr_writes >= max_nr_writes) |
| 970 | break; |
| 971 | } |
| 972 | |
| 973 | return nr_reads + nr_writes; |
| 974 | } |
| 975 | |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 976 | static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 977 | { |
| 978 | unsigned int nr_disp = 0; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 979 | |
| 980 | while (1) { |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 981 | struct throtl_grp *tg = throtl_rb_first(parent_sq); |
| 982 | struct throtl_service_queue *sq = &tg->service_queue; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 983 | |
| 984 | if (!tg) |
| 985 | break; |
| 986 | |
| 987 | if (time_before(jiffies, tg->disptime)) |
| 988 | break; |
| 989 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 990 | throtl_dequeue_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 991 | |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 992 | nr_disp += throtl_dispatch_tg(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 993 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 994 | if (sq->nr_queued[0] || sq->nr_queued[1]) |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 995 | tg_update_disptime(tg); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 996 | |
| 997 | if (nr_disp >= throtl_quantum) |
| 998 | break; |
| 999 | } |
| 1000 | |
| 1001 | return nr_disp; |
| 1002 | } |
| 1003 | |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1004 | /** |
| 1005 | * throtl_pending_timer_fn - timer function for service_queue->pending_timer |
| 1006 | * @arg: the throtl_service_queue being serviced |
| 1007 | * |
| 1008 | * This timer is armed when a child throtl_grp with active bio's become |
| 1009 | * pending and queued on the service_queue's pending_tree and expires when |
| 1010 | * the first child throtl_grp should be dispatched. This function |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1011 | * dispatches bio's from the children throtl_grps to the parent |
| 1012 | * service_queue. |
| 1013 | * |
| 1014 | * If the parent's parent is another throtl_grp, dispatching is propagated |
| 1015 | * by either arming its pending_timer or repeating dispatch directly. If |
| 1016 | * the top-level service_tree is reached, throtl_data->dispatch_work is |
| 1017 | * kicked so that the ready bio's are issued. |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1018 | */ |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1019 | static void throtl_pending_timer_fn(unsigned long arg) |
| 1020 | { |
| 1021 | struct throtl_service_queue *sq = (void *)arg; |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1022 | struct throtl_grp *tg = sq_to_tg(sq); |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1023 | struct throtl_data *td = sq_to_td(sq); |
Tejun Heo | cb76199 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1024 | struct request_queue *q = td->queue; |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1025 | struct throtl_service_queue *parent_sq; |
| 1026 | bool dispatched; |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1027 | int ret; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1028 | |
| 1029 | spin_lock_irq(q->queue_lock); |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1030 | again: |
| 1031 | parent_sq = sq->parent_sq; |
| 1032 | dispatched = false; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1033 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1034 | while (true) { |
| 1035 | throtl_log(sq, "dispatch nr_queued=%u read=%u write=%u", |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1036 | sq->nr_queued[READ] + sq->nr_queued[WRITE], |
| 1037 | sq->nr_queued[READ], sq->nr_queued[WRITE]); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1038 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1039 | ret = throtl_select_dispatch(sq); |
| 1040 | if (ret) { |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1041 | throtl_log(sq, "bios disp=%u", ret); |
| 1042 | dispatched = true; |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1043 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1044 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1045 | if (throtl_schedule_next_dispatch(sq, false)) |
| 1046 | break; |
| 1047 | |
| 1048 | /* this dispatch windows is still open, relax and repeat */ |
| 1049 | spin_unlock_irq(q->queue_lock); |
| 1050 | cpu_relax(); |
| 1051 | spin_lock_irq(q->queue_lock); |
| 1052 | } |
Tejun Heo | 6a52560 | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1053 | |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1054 | if (!dispatched) |
| 1055 | goto out_unlock; |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1056 | |
Tejun Heo | 2e48a53 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1057 | if (parent_sq) { |
| 1058 | /* @parent_sq is another throl_grp, propagate dispatch */ |
| 1059 | if (tg->flags & THROTL_TG_WAS_EMPTY) { |
| 1060 | tg_update_disptime(tg); |
| 1061 | if (!throtl_schedule_next_dispatch(parent_sq, false)) { |
| 1062 | /* window is already open, repeat dispatching */ |
| 1063 | sq = parent_sq; |
| 1064 | tg = sq_to_tg(sq); |
| 1065 | goto again; |
| 1066 | } |
| 1067 | } |
| 1068 | } else { |
| 1069 | /* reached the top-level, queue issueing */ |
| 1070 | queue_work(kthrotld_workqueue, &td->dispatch_work); |
| 1071 | } |
| 1072 | out_unlock: |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1073 | spin_unlock_irq(q->queue_lock); |
| 1074 | } |
| 1075 | |
| 1076 | /** |
| 1077 | * blk_throtl_dispatch_work_fn - work function for throtl_data->dispatch_work |
| 1078 | * @work: work item being executed |
| 1079 | * |
| 1080 | * This function is queued for execution when bio's reach the bio_lists[] |
| 1081 | * of throtl_data->service_queue. Those bio's are ready and issued by this |
| 1082 | * function. |
| 1083 | */ |
Fabian Frederick | 8876e14 | 2014-04-17 21:41:16 +0200 | [diff] [blame] | 1084 | static void blk_throtl_dispatch_work_fn(struct work_struct *work) |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1085 | { |
| 1086 | struct throtl_data *td = container_of(work, struct throtl_data, |
| 1087 | dispatch_work); |
| 1088 | struct throtl_service_queue *td_sq = &td->service_queue; |
| 1089 | struct request_queue *q = td->queue; |
| 1090 | struct bio_list bio_list_on_stack; |
| 1091 | struct bio *bio; |
| 1092 | struct blk_plug plug; |
| 1093 | int rw; |
| 1094 | |
| 1095 | bio_list_init(&bio_list_on_stack); |
| 1096 | |
| 1097 | spin_lock_irq(q->queue_lock); |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1098 | for (rw = READ; rw <= WRITE; rw++) |
| 1099 | while ((bio = throtl_pop_queued(&td_sq->queued[rw], NULL))) |
| 1100 | bio_list_add(&bio_list_on_stack, bio); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1101 | spin_unlock_irq(q->queue_lock); |
| 1102 | |
Tejun Heo | 6e1a570 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1103 | if (!bio_list_empty(&bio_list_on_stack)) { |
Vivek Goyal | 69d60eb | 2011-03-09 08:27:37 +0100 | [diff] [blame] | 1104 | blk_start_plug(&plug); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1105 | while((bio = bio_list_pop(&bio_list_on_stack))) |
| 1106 | generic_make_request(bio); |
Vivek Goyal | 69d60eb | 2011-03-09 08:27:37 +0100 | [diff] [blame] | 1107 | blk_finish_plug(&plug); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1108 | } |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1109 | } |
| 1110 | |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1111 | static u64 tg_prfill_conf_u64(struct seq_file *sf, struct blkg_policy_data *pd, |
| 1112 | int off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1113 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1114 | struct throtl_grp *tg = pd_to_tg(pd); |
| 1115 | u64 v = *(u64 *)((void *)tg + off); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1116 | |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1117 | if (v == -1) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1118 | return 0; |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1119 | return __blkg_prfill_u64(sf, pd, v); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1120 | } |
| 1121 | |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1122 | static u64 tg_prfill_conf_uint(struct seq_file *sf, struct blkg_policy_data *pd, |
| 1123 | int off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1124 | { |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1125 | struct throtl_grp *tg = pd_to_tg(pd); |
| 1126 | unsigned int v = *(unsigned int *)((void *)tg + off); |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1127 | |
| 1128 | if (v == -1) |
| 1129 | return 0; |
Tejun Heo | f95a04a | 2012-04-16 13:57:26 -0700 | [diff] [blame] | 1130 | return __blkg_prfill_u64(sf, pd, v); |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1131 | } |
| 1132 | |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1133 | static int tg_print_conf_u64(struct seq_file *sf, void *v) |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1134 | { |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1135 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_u64, |
| 1136 | &blkcg_policy_throtl, seq_cft(sf)->private, false); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1137 | return 0; |
| 1138 | } |
| 1139 | |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1140 | static int tg_print_conf_uint(struct seq_file *sf, void *v) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1141 | { |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1142 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_uint, |
| 1143 | &blkcg_policy_throtl, seq_cft(sf)->private, false); |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1144 | return 0; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1145 | } |
| 1146 | |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1147 | static void tg_conf_updated(struct throtl_grp *tg) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1148 | { |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1149 | struct throtl_service_queue *sq = &tg->service_queue; |
Tejun Heo | 492eb21 | 2013-08-08 20:11:25 -0400 | [diff] [blame] | 1150 | struct cgroup_subsys_state *pos_css; |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1151 | struct blkcg_gq *blkg; |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1152 | |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1153 | throtl_log(&tg->service_queue, |
| 1154 | "limit change rbps=%llu wbps=%llu riops=%u wiops=%u", |
| 1155 | tg->bps[READ], tg->bps[WRITE], |
| 1156 | tg->iops[READ], tg->iops[WRITE]); |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1157 | |
| 1158 | /* |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1159 | * Update has_rules[] flags for the updated tg's subtree. A tg is |
| 1160 | * considered to have rules if either the tg itself or any of its |
| 1161 | * ancestors has rules. This identifies groups without any |
| 1162 | * restrictions in the whole hierarchy and allows them to bypass |
| 1163 | * blk-throttle. |
| 1164 | */ |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1165 | blkg_for_each_descendant_pre(blkg, pos_css, tg_to_blkg(tg)) |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1166 | tg_update_has_rules(blkg_to_tg(blkg)); |
| 1167 | |
| 1168 | /* |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1169 | * We're already holding queue_lock and know @tg is valid. Let's |
| 1170 | * apply the new config directly. |
| 1171 | * |
| 1172 | * Restart the slices for both READ and WRITES. It might happen |
| 1173 | * that a group's limit are dropped suddenly and we don't want to |
| 1174 | * account recently dispatched IO with new low rate. |
| 1175 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1176 | throtl_start_new_slice(tg, 0); |
| 1177 | throtl_start_new_slice(tg, 1); |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1178 | |
Tejun Heo | 5b2c16a | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1179 | if (tg->flags & THROTL_TG_PENDING) { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1180 | tg_update_disptime(tg); |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1181 | throtl_schedule_next_dispatch(sq->parent_sq, true); |
Tejun Heo | 632b449 | 2013-05-14 13:52:31 -0700 | [diff] [blame] | 1182 | } |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1183 | } |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1184 | |
Tejun Heo | 69948b0 | 2015-08-18 14:55:32 -0700 | [diff] [blame] | 1185 | static ssize_t tg_set_conf(struct kernfs_open_file *of, |
| 1186 | char *buf, size_t nbytes, loff_t off, bool is_u64) |
| 1187 | { |
| 1188 | struct blkcg *blkcg = css_to_blkcg(of_css(of)); |
| 1189 | struct blkg_conf_ctx ctx; |
| 1190 | struct throtl_grp *tg; |
| 1191 | int ret; |
| 1192 | u64 v; |
| 1193 | |
| 1194 | ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx); |
| 1195 | if (ret) |
| 1196 | return ret; |
| 1197 | |
| 1198 | ret = -EINVAL; |
| 1199 | if (sscanf(ctx.body, "%llu", &v) != 1) |
| 1200 | goto out_finish; |
| 1201 | if (!v) |
| 1202 | v = -1; |
| 1203 | |
| 1204 | tg = blkg_to_tg(ctx.blkg); |
| 1205 | |
| 1206 | if (is_u64) |
| 1207 | *(u64 *)((void *)tg + of_cft(of)->private) = v; |
| 1208 | else |
| 1209 | *(unsigned int *)((void *)tg + of_cft(of)->private) = v; |
| 1210 | |
| 1211 | tg_conf_updated(tg); |
Tejun Heo | 36aa9e5 | 2015-08-18 14:55:31 -0700 | [diff] [blame] | 1212 | ret = 0; |
| 1213 | out_finish: |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1214 | blkg_conf_finish(&ctx); |
Tejun Heo | 36aa9e5 | 2015-08-18 14:55:31 -0700 | [diff] [blame] | 1215 | return ret ?: nbytes; |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1216 | } |
| 1217 | |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1218 | static ssize_t tg_set_conf_u64(struct kernfs_open_file *of, |
| 1219 | char *buf, size_t nbytes, loff_t off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1220 | { |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1221 | return tg_set_conf(of, buf, nbytes, off, true); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1222 | } |
| 1223 | |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1224 | static ssize_t tg_set_conf_uint(struct kernfs_open_file *of, |
| 1225 | char *buf, size_t nbytes, loff_t off) |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1226 | { |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1227 | return tg_set_conf(of, buf, nbytes, off, false); |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1228 | } |
| 1229 | |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1230 | static struct cftype throtl_legacy_files[] = { |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1231 | { |
| 1232 | .name = "throttle.read_bps_device", |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1233 | .private = offsetof(struct throtl_grp, bps[READ]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1234 | .seq_show = tg_print_conf_u64, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1235 | .write = tg_set_conf_u64, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1236 | }, |
| 1237 | { |
| 1238 | .name = "throttle.write_bps_device", |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1239 | .private = offsetof(struct throtl_grp, bps[WRITE]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1240 | .seq_show = tg_print_conf_u64, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1241 | .write = tg_set_conf_u64, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1242 | }, |
| 1243 | { |
| 1244 | .name = "throttle.read_iops_device", |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1245 | .private = offsetof(struct throtl_grp, iops[READ]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1246 | .seq_show = tg_print_conf_uint, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1247 | .write = tg_set_conf_uint, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1248 | }, |
| 1249 | { |
| 1250 | .name = "throttle.write_iops_device", |
Tejun Heo | af133ce | 2012-04-01 14:38:44 -0700 | [diff] [blame] | 1251 | .private = offsetof(struct throtl_grp, iops[WRITE]), |
Tejun Heo | 2da8ca8 | 2013-12-05 12:28:04 -0500 | [diff] [blame] | 1252 | .seq_show = tg_print_conf_uint, |
Tejun Heo | 451af50 | 2014-05-13 12:16:21 -0400 | [diff] [blame] | 1253 | .write = tg_set_conf_uint, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1254 | }, |
| 1255 | { |
| 1256 | .name = "throttle.io_service_bytes", |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 1257 | .private = (unsigned long)&blkcg_policy_throtl, |
| 1258 | .seq_show = blkg_print_stat_bytes, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1259 | }, |
| 1260 | { |
| 1261 | .name = "throttle.io_serviced", |
Tejun Heo | 77ea733 | 2015-08-18 14:55:24 -0700 | [diff] [blame] | 1262 | .private = (unsigned long)&blkcg_policy_throtl, |
| 1263 | .seq_show = blkg_print_stat_ios, |
Tejun Heo | 60c2bc2 | 2012-04-01 14:38:43 -0700 | [diff] [blame] | 1264 | }, |
| 1265 | { } /* terminate */ |
| 1266 | }; |
| 1267 | |
Vivek Goyal | da52777 | 2011-03-02 19:05:33 -0500 | [diff] [blame] | 1268 | static void throtl_shutdown_wq(struct request_queue *q) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1269 | { |
| 1270 | struct throtl_data *td = q->td; |
| 1271 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1272 | cancel_work_sync(&td->dispatch_work); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1273 | } |
| 1274 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1275 | static struct blkcg_policy blkcg_policy_throtl = { |
Tejun Heo | 880f50e | 2015-08-18 14:55:30 -0700 | [diff] [blame] | 1276 | .legacy_cftypes = throtl_legacy_files, |
Tejun Heo | f9fcc2d | 2012-04-16 13:57:27 -0700 | [diff] [blame] | 1277 | |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 1278 | .pd_alloc_fn = throtl_pd_alloc, |
Tejun Heo | f9fcc2d | 2012-04-16 13:57:27 -0700 | [diff] [blame] | 1279 | .pd_init_fn = throtl_pd_init, |
Tejun Heo | 693e751 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1280 | .pd_online_fn = throtl_pd_online, |
Tejun Heo | 001bea7 | 2015-08-18 14:55:11 -0700 | [diff] [blame] | 1281 | .pd_free_fn = throtl_pd_free, |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1282 | }; |
| 1283 | |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 1284 | bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, |
| 1285 | struct bio *bio) |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1286 | { |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1287 | struct throtl_qnode *qn = NULL; |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 1288 | struct throtl_grp *tg = blkg_to_tg(blkg ?: q->root_blkg); |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1289 | struct throtl_service_queue *sq; |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1290 | bool rw = bio_data_dir(bio); |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 1291 | bool throttled = false; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1292 | |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 1293 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 1294 | |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1295 | /* see throtl_charge_bio() */ |
Tejun Heo | ae11889 | 2015-08-18 14:55:20 -0700 | [diff] [blame] | 1296 | if ((bio->bi_rw & REQ_THROTTLED) || !tg->has_rules[rw]) |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 1297 | goto out; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1298 | |
| 1299 | spin_lock_irq(q->queue_lock); |
Tejun Heo | c9589f0 | 2015-08-18 14:55:19 -0700 | [diff] [blame] | 1300 | |
| 1301 | if (unlikely(blk_queue_bypass(q))) |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 1302 | goto out_unlock; |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1303 | |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1304 | sq = &tg->service_queue; |
| 1305 | |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1306 | while (true) { |
| 1307 | /* throtl is FIFO - if bios are already queued, should queue */ |
| 1308 | if (sq->nr_queued[rw]) |
| 1309 | break; |
Vivek Goyal | de701c7 | 2011-03-07 21:09:32 +0100 | [diff] [blame] | 1310 | |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1311 | /* if above limits, break to queue */ |
| 1312 | if (!tg_may_dispatch(tg, bio, NULL)) |
| 1313 | break; |
| 1314 | |
| 1315 | /* within limits, let's charge and dispatch directly */ |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1316 | throtl_charge_bio(tg, bio); |
Vivek Goyal | 04521db | 2011-03-22 21:54:29 +0100 | [diff] [blame] | 1317 | |
| 1318 | /* |
| 1319 | * We need to trim slice even when bios are not being queued |
| 1320 | * otherwise it might happen that a bio is not queued for |
| 1321 | * a long time and slice keeps on extending and trim is not |
| 1322 | * called for a long time. Now if limits are reduced suddenly |
| 1323 | * we take into account all the IO dispatched so far at new |
| 1324 | * low rate and * newly queued IO gets a really long dispatch |
| 1325 | * time. |
| 1326 | * |
| 1327 | * So keep on trimming slice even if bio is not queued. |
| 1328 | */ |
Tejun Heo | 0f3457f | 2013-05-14 13:52:32 -0700 | [diff] [blame] | 1329 | throtl_trim_slice(tg, rw); |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1330 | |
| 1331 | /* |
| 1332 | * @bio passed through this layer without being throttled. |
| 1333 | * Climb up the ladder. If we''re already at the top, it |
| 1334 | * can be executed directly. |
| 1335 | */ |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1336 | qn = &tg->qnode_on_parent[rw]; |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1337 | sq = sq->parent_sq; |
| 1338 | tg = sq_to_tg(sq); |
| 1339 | if (!tg) |
| 1340 | goto out_unlock; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1341 | } |
| 1342 | |
Tejun Heo | 9e660ac | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1343 | /* out-of-limit, queue to @tg */ |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1344 | throtl_log(sq, "[%c] bio. bdisp=%llu sz=%u bps=%llu iodisp=%u iops=%u queued=%d/%d", |
| 1345 | rw == READ ? 'R' : 'W', |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 1346 | tg->bytes_disp[rw], bio->bi_iter.bi_size, tg->bps[rw], |
Tejun Heo | fda6f27 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1347 | tg->io_disp[rw], tg->iops[rw], |
| 1348 | sq->nr_queued[READ], sq->nr_queued[WRITE]); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1349 | |
Tejun Heo | 671058f | 2012-03-05 13:15:29 -0800 | [diff] [blame] | 1350 | bio_associate_current(bio); |
Tejun Heo | 6bc9c2b | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1351 | tg->td->nr_queued[rw]++; |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1352 | throtl_add_bio_tg(bio, qn, tg); |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 1353 | throttled = true; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1354 | |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1355 | /* |
| 1356 | * Update @tg's dispatch time and force schedule dispatch if @tg |
| 1357 | * was empty before @bio. The forced scheduling isn't likely to |
| 1358 | * cause undue delay as @bio is likely to be dispatched directly if |
| 1359 | * its @tg's disptime is not in the future. |
| 1360 | */ |
Tejun Heo | 0e9f416 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1361 | if (tg->flags & THROTL_TG_WAS_EMPTY) { |
Tejun Heo | 77216b0 | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1362 | tg_update_disptime(tg); |
Tejun Heo | 7f52f98 | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1363 | throtl_schedule_next_dispatch(tg->service_queue.parent_sq, true); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1364 | } |
| 1365 | |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 1366 | out_unlock: |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1367 | spin_unlock_irq(q->queue_lock); |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 1368 | out: |
Tejun Heo | 2a0f61e | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1369 | /* |
| 1370 | * As multiple blk-throtls may stack in the same issue path, we |
| 1371 | * don't want bios to leave with the flag set. Clear the flag if |
| 1372 | * being issued. |
| 1373 | */ |
| 1374 | if (!throttled) |
| 1375 | bio->bi_rw &= ~REQ_THROTTLED; |
Tejun Heo | bc16a4f | 2011-10-19 14:33:01 +0200 | [diff] [blame] | 1376 | return throttled; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1377 | } |
| 1378 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1379 | /* |
| 1380 | * Dispatch all bios from all children tg's queued on @parent_sq. On |
| 1381 | * return, @parent_sq is guaranteed to not have any active children tg's |
| 1382 | * and all bios from previously active tg's are on @parent_sq->bio_lists[]. |
| 1383 | */ |
| 1384 | static void tg_drain_bios(struct throtl_service_queue *parent_sq) |
| 1385 | { |
| 1386 | struct throtl_grp *tg; |
| 1387 | |
| 1388 | while ((tg = throtl_rb_first(parent_sq))) { |
| 1389 | struct throtl_service_queue *sq = &tg->service_queue; |
| 1390 | struct bio *bio; |
| 1391 | |
| 1392 | throtl_dequeue_tg(tg); |
| 1393 | |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1394 | while ((bio = throtl_peek_queued(&sq->queued[READ]))) |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1395 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1396 | while ((bio = throtl_peek_queued(&sq->queued[WRITE]))) |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1397 | tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
| 1398 | } |
| 1399 | } |
| 1400 | |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 1401 | /** |
| 1402 | * blk_throtl_drain - drain throttled bios |
| 1403 | * @q: request_queue to drain throttled bios for |
| 1404 | * |
| 1405 | * Dispatch all currently throttled bios on @q through ->make_request_fn(). |
| 1406 | */ |
| 1407 | void blk_throtl_drain(struct request_queue *q) |
| 1408 | __releases(q->queue_lock) __acquires(q->queue_lock) |
| 1409 | { |
| 1410 | struct throtl_data *td = q->td; |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1411 | struct blkcg_gq *blkg; |
Tejun Heo | 492eb21 | 2013-08-08 20:11:25 -0400 | [diff] [blame] | 1412 | struct cgroup_subsys_state *pos_css; |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 1413 | struct bio *bio; |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1414 | int rw; |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 1415 | |
Andi Kleen | 8bcb6c7 | 2012-03-30 12:33:28 +0200 | [diff] [blame] | 1416 | queue_lockdep_assert_held(q); |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1417 | rcu_read_lock(); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 1418 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1419 | /* |
| 1420 | * Drain each tg while doing post-order walk on the blkg tree, so |
| 1421 | * that all bios are propagated to td->service_queue. It'd be |
| 1422 | * better to walk service_queue tree directly but blkg walk is |
| 1423 | * easier. |
| 1424 | */ |
Tejun Heo | 492eb21 | 2013-08-08 20:11:25 -0400 | [diff] [blame] | 1425 | blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1426 | tg_drain_bios(&blkg_to_tg(blkg)->service_queue); |
Tejun Heo | 73f0d49 | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1427 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1428 | /* finally, transfer bios from top-level tg's into the td */ |
| 1429 | tg_drain_bios(&td->service_queue); |
| 1430 | |
| 1431 | rcu_read_unlock(); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 1432 | spin_unlock_irq(q->queue_lock); |
| 1433 | |
Tejun Heo | 2a12f0d | 2013-05-14 13:52:37 -0700 | [diff] [blame] | 1434 | /* all bios now should be in td->service_queue, issue them */ |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1435 | for (rw = READ; rw <= WRITE; rw++) |
Tejun Heo | c5cc207 | 2013-05-14 13:52:38 -0700 | [diff] [blame] | 1436 | while ((bio = throtl_pop_queued(&td->service_queue.queued[rw], |
| 1437 | NULL))) |
Tejun Heo | 651930b | 2013-05-14 13:52:35 -0700 | [diff] [blame] | 1438 | generic_make_request(bio); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 1439 | |
| 1440 | spin_lock_irq(q->queue_lock); |
| 1441 | } |
| 1442 | |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1443 | int blk_throtl_init(struct request_queue *q) |
| 1444 | { |
| 1445 | struct throtl_data *td; |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1446 | int ret; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1447 | |
| 1448 | td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node); |
| 1449 | if (!td) |
| 1450 | return -ENOMEM; |
| 1451 | |
Tejun Heo | 69df0ab | 2013-05-14 13:52:36 -0700 | [diff] [blame] | 1452 | INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); |
Tejun Heo | b2ce264 | 2015-08-18 14:55:13 -0700 | [diff] [blame] | 1453 | throtl_service_queue_init(&td->service_queue); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1454 | |
Tejun Heo | cd1604f | 2012-03-05 13:15:06 -0800 | [diff] [blame] | 1455 | q->td = td; |
Vivek Goyal | 29b1258 | 2011-05-19 15:38:24 -0400 | [diff] [blame] | 1456 | td->queue = q; |
Vivek Goyal | 02977e4 | 2010-10-01 14:49:48 +0200 | [diff] [blame] | 1457 | |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1458 | /* activate policy */ |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1459 | ret = blkcg_activate_policy(q, &blkcg_policy_throtl); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1460 | if (ret) |
Vivek Goyal | 29b1258 | 2011-05-19 15:38:24 -0400 | [diff] [blame] | 1461 | kfree(td); |
Tejun Heo | a2b1693 | 2012-04-13 13:11:33 -0700 | [diff] [blame] | 1462 | return ret; |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1463 | } |
| 1464 | |
| 1465 | void blk_throtl_exit(struct request_queue *q) |
| 1466 | { |
Tejun Heo | c875f4d | 2012-03-05 13:15:22 -0800 | [diff] [blame] | 1467 | BUG_ON(!q->td); |
Vivek Goyal | da52777 | 2011-03-02 19:05:33 -0500 | [diff] [blame] | 1468 | throtl_shutdown_wq(q); |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1469 | blkcg_deactivate_policy(q, &blkcg_policy_throtl); |
Tejun Heo | c9a929d | 2011-10-19 14:42:16 +0200 | [diff] [blame] | 1470 | kfree(q->td); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1471 | } |
| 1472 | |
| 1473 | static int __init throtl_init(void) |
| 1474 | { |
Vivek Goyal | 450adcb | 2011-03-01 13:40:54 -0500 | [diff] [blame] | 1475 | kthrotld_workqueue = alloc_workqueue("kthrotld", WQ_MEM_RECLAIM, 0); |
| 1476 | if (!kthrotld_workqueue) |
| 1477 | panic("Failed to create kthrotld\n"); |
| 1478 | |
Tejun Heo | 3c79839 | 2012-04-16 13:57:25 -0700 | [diff] [blame] | 1479 | return blkcg_policy_register(&blkcg_policy_throtl); |
Vivek Goyal | e43473b | 2010-09-15 17:06:35 -0400 | [diff] [blame] | 1480 | } |
| 1481 | |
| 1482 | module_init(throtl_init); |