Paolo Valente | 70f2871 | 2013-05-09 19:10:02 +0200 | [diff] [blame] | 1 | /* |
| 2 | * BFQ: Hierarchical B-WF2Q+ scheduler. |
| 3 | * |
| 4 | * Based on ideas and code from CFQ: |
| 5 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
| 6 | * |
| 7 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> |
| 8 | * Paolo Valente <paolo.valente@unimore.it> |
| 9 | * |
| 10 | * Copyright (C) 2010 Paolo Valente <paolo.valente@unimore.it> |
| 11 | */ |
| 12 | |
| 13 | #ifdef CONFIG_CGROUP_BFQIO |
| 14 | #define for_each_entity(entity) \ |
| 15 | for (; entity != NULL; entity = entity->parent) |
| 16 | |
| 17 | #define for_each_entity_safe(entity, parent) \ |
| 18 | for (; entity && ({ parent = entity->parent; 1; }); entity = parent) |
| 19 | |
| 20 | static struct bfq_entity *bfq_lookup_next_entity(struct bfq_sched_data *sd, |
| 21 | int extract, |
| 22 | struct bfq_data *bfqd); |
| 23 | |
| 24 | static inline void bfq_update_budget(struct bfq_entity *next_in_service) |
| 25 | { |
| 26 | struct bfq_entity *bfqg_entity; |
| 27 | struct bfq_group *bfqg; |
| 28 | struct bfq_sched_data *group_sd; |
| 29 | |
| 30 | BUG_ON(next_in_service == NULL); |
| 31 | |
| 32 | group_sd = next_in_service->sched_data; |
| 33 | |
| 34 | bfqg = container_of(group_sd, struct bfq_group, sched_data); |
| 35 | /* |
| 36 | * bfq_group's my_entity field is not NULL only if the group |
| 37 | * is not the root group. We must not touch the root entity |
| 38 | * as it must never become an in-service entity. |
| 39 | */ |
| 40 | bfqg_entity = bfqg->my_entity; |
| 41 | if (bfqg_entity != NULL) |
| 42 | bfqg_entity->budget = next_in_service->budget; |
| 43 | } |
| 44 | |
| 45 | static int bfq_update_next_in_service(struct bfq_sched_data *sd) |
| 46 | { |
| 47 | struct bfq_entity *next_in_service; |
| 48 | |
| 49 | if (sd->in_service_entity != NULL) |
| 50 | /* will update/requeue at the end of service */ |
| 51 | return 0; |
| 52 | |
| 53 | /* |
| 54 | * NOTE: this can be improved in many ways, such as returning |
| 55 | * 1 (and thus propagating upwards the update) only when the |
| 56 | * budget changes, or caching the bfqq that will be scheduled |
| 57 | * next from this subtree. By now we worry more about |
| 58 | * correctness than about performance... |
| 59 | */ |
| 60 | next_in_service = bfq_lookup_next_entity(sd, 0, NULL); |
| 61 | sd->next_in_service = next_in_service; |
| 62 | |
| 63 | if (next_in_service != NULL) |
| 64 | bfq_update_budget(next_in_service); |
| 65 | |
| 66 | return 1; |
| 67 | } |
| 68 | |
| 69 | static inline void bfq_check_next_in_service(struct bfq_sched_data *sd, |
| 70 | struct bfq_entity *entity) |
| 71 | { |
| 72 | BUG_ON(sd->next_in_service != entity); |
| 73 | } |
| 74 | #else |
| 75 | #define for_each_entity(entity) \ |
| 76 | for (; entity != NULL; entity = NULL) |
| 77 | |
| 78 | #define for_each_entity_safe(entity, parent) \ |
| 79 | for (parent = NULL; entity != NULL; entity = parent) |
| 80 | |
| 81 | static inline int bfq_update_next_in_service(struct bfq_sched_data *sd) |
| 82 | { |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | static inline void bfq_check_next_in_service(struct bfq_sched_data *sd, |
| 87 | struct bfq_entity *entity) |
| 88 | { |
| 89 | } |
| 90 | |
| 91 | static inline void bfq_update_budget(struct bfq_entity *next_in_service) |
| 92 | { |
| 93 | } |
| 94 | #endif |
| 95 | |
| 96 | /* |
| 97 | * Shift for timestamp calculations. This actually limits the maximum |
| 98 | * service allowed in one timestamp delta (small shift values increase it), |
| 99 | * the maximum total weight that can be used for the queues in the system |
| 100 | * (big shift values increase it), and the period of virtual time |
| 101 | * wraparounds. |
| 102 | */ |
| 103 | #define WFQ_SERVICE_SHIFT 22 |
| 104 | |
| 105 | /** |
| 106 | * bfq_gt - compare two timestamps. |
| 107 | * @a: first ts. |
| 108 | * @b: second ts. |
| 109 | * |
| 110 | * Return @a > @b, dealing with wrapping correctly. |
| 111 | */ |
| 112 | static inline int bfq_gt(u64 a, u64 b) |
| 113 | { |
| 114 | return (s64)(a - b) > 0; |
| 115 | } |
| 116 | |
| 117 | static inline struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity) |
| 118 | { |
| 119 | struct bfq_queue *bfqq = NULL; |
| 120 | |
| 121 | BUG_ON(entity == NULL); |
| 122 | |
| 123 | if (entity->my_sched_data == NULL) |
| 124 | bfqq = container_of(entity, struct bfq_queue, entity); |
| 125 | |
| 126 | return bfqq; |
| 127 | } |
| 128 | |
| 129 | |
| 130 | /** |
| 131 | * bfq_delta - map service into the virtual time domain. |
| 132 | * @service: amount of service. |
| 133 | * @weight: scale factor (weight of an entity or weight sum). |
| 134 | */ |
| 135 | static inline u64 bfq_delta(unsigned long service, |
| 136 | unsigned long weight) |
| 137 | { |
| 138 | u64 d = (u64)service << WFQ_SERVICE_SHIFT; |
| 139 | |
| 140 | do_div(d, weight); |
| 141 | return d; |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * bfq_calc_finish - assign the finish time to an entity. |
| 146 | * @entity: the entity to act upon. |
| 147 | * @service: the service to be charged to the entity. |
| 148 | */ |
| 149 | static inline void bfq_calc_finish(struct bfq_entity *entity, |
| 150 | unsigned long service) |
| 151 | { |
| 152 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 153 | |
| 154 | BUG_ON(entity->weight == 0); |
| 155 | |
| 156 | entity->finish = entity->start + |
| 157 | bfq_delta(service, entity->weight); |
| 158 | |
| 159 | if (bfqq != NULL) { |
| 160 | bfq_log_bfqq(bfqq->bfqd, bfqq, |
| 161 | "calc_finish: serv %lu, w %d", |
| 162 | service, entity->weight); |
| 163 | bfq_log_bfqq(bfqq->bfqd, bfqq, |
| 164 | "calc_finish: start %llu, finish %llu, delta %llu", |
| 165 | entity->start, entity->finish, |
| 166 | bfq_delta(service, entity->weight)); |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | /** |
| 171 | * bfq_entity_of - get an entity from a node. |
| 172 | * @node: the node field of the entity. |
| 173 | * |
| 174 | * Convert a node pointer to the relative entity. This is used only |
| 175 | * to simplify the logic of some functions and not as the generic |
| 176 | * conversion mechanism because, e.g., in the tree walking functions, |
| 177 | * the check for a %NULL value would be redundant. |
| 178 | */ |
| 179 | static inline struct bfq_entity *bfq_entity_of(struct rb_node *node) |
| 180 | { |
| 181 | struct bfq_entity *entity = NULL; |
| 182 | |
| 183 | if (node != NULL) |
| 184 | entity = rb_entry(node, struct bfq_entity, rb_node); |
| 185 | |
| 186 | return entity; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * bfq_extract - remove an entity from a tree. |
| 191 | * @root: the tree root. |
| 192 | * @entity: the entity to remove. |
| 193 | */ |
| 194 | static inline void bfq_extract(struct rb_root *root, |
| 195 | struct bfq_entity *entity) |
| 196 | { |
| 197 | BUG_ON(entity->tree != root); |
| 198 | |
| 199 | entity->tree = NULL; |
| 200 | rb_erase(&entity->rb_node, root); |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * bfq_idle_extract - extract an entity from the idle tree. |
| 205 | * @st: the service tree of the owning @entity. |
| 206 | * @entity: the entity being removed. |
| 207 | */ |
| 208 | static void bfq_idle_extract(struct bfq_service_tree *st, |
| 209 | struct bfq_entity *entity) |
| 210 | { |
| 211 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 212 | struct rb_node *next; |
| 213 | |
| 214 | BUG_ON(entity->tree != &st->idle); |
| 215 | |
| 216 | if (entity == st->first_idle) { |
| 217 | next = rb_next(&entity->rb_node); |
| 218 | st->first_idle = bfq_entity_of(next); |
| 219 | } |
| 220 | |
| 221 | if (entity == st->last_idle) { |
| 222 | next = rb_prev(&entity->rb_node); |
| 223 | st->last_idle = bfq_entity_of(next); |
| 224 | } |
| 225 | |
| 226 | bfq_extract(&st->idle, entity); |
| 227 | |
| 228 | if (bfqq != NULL) |
| 229 | list_del(&bfqq->bfqq_list); |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * bfq_insert - generic tree insertion. |
| 234 | * @root: tree root. |
| 235 | * @entity: entity to insert. |
| 236 | * |
| 237 | * This is used for the idle and the active tree, since they are both |
| 238 | * ordered by finish time. |
| 239 | */ |
| 240 | static void bfq_insert(struct rb_root *root, struct bfq_entity *entity) |
| 241 | { |
| 242 | struct bfq_entity *entry; |
| 243 | struct rb_node **node = &root->rb_node; |
| 244 | struct rb_node *parent = NULL; |
| 245 | |
| 246 | BUG_ON(entity->tree != NULL); |
| 247 | |
| 248 | while (*node != NULL) { |
| 249 | parent = *node; |
| 250 | entry = rb_entry(parent, struct bfq_entity, rb_node); |
| 251 | |
| 252 | if (bfq_gt(entry->finish, entity->finish)) |
| 253 | node = &parent->rb_left; |
| 254 | else |
| 255 | node = &parent->rb_right; |
| 256 | } |
| 257 | |
| 258 | rb_link_node(&entity->rb_node, parent, node); |
| 259 | rb_insert_color(&entity->rb_node, root); |
| 260 | |
| 261 | entity->tree = root; |
| 262 | } |
| 263 | |
| 264 | /** |
| 265 | * bfq_update_min - update the min_start field of a entity. |
| 266 | * @entity: the entity to update. |
| 267 | * @node: one of its children. |
| 268 | * |
| 269 | * This function is called when @entity may store an invalid value for |
| 270 | * min_start due to updates to the active tree. The function assumes |
| 271 | * that the subtree rooted at @node (which may be its left or its right |
| 272 | * child) has a valid min_start value. |
| 273 | */ |
| 274 | static inline void bfq_update_min(struct bfq_entity *entity, |
| 275 | struct rb_node *node) |
| 276 | { |
| 277 | struct bfq_entity *child; |
| 278 | |
| 279 | if (node != NULL) { |
| 280 | child = rb_entry(node, struct bfq_entity, rb_node); |
| 281 | if (bfq_gt(entity->min_start, child->min_start)) |
| 282 | entity->min_start = child->min_start; |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | /** |
| 287 | * bfq_update_active_node - recalculate min_start. |
| 288 | * @node: the node to update. |
| 289 | * |
| 290 | * @node may have changed position or one of its children may have moved, |
| 291 | * this function updates its min_start value. The left and right subtrees |
| 292 | * are assumed to hold a correct min_start value. |
| 293 | */ |
| 294 | static inline void bfq_update_active_node(struct rb_node *node) |
| 295 | { |
| 296 | struct bfq_entity *entity = rb_entry(node, struct bfq_entity, rb_node); |
| 297 | |
| 298 | entity->min_start = entity->start; |
| 299 | bfq_update_min(entity, node->rb_right); |
| 300 | bfq_update_min(entity, node->rb_left); |
| 301 | } |
| 302 | |
| 303 | /** |
| 304 | * bfq_update_active_tree - update min_start for the whole active tree. |
| 305 | * @node: the starting node. |
| 306 | * |
| 307 | * @node must be the deepest modified node after an update. This function |
| 308 | * updates its min_start using the values held by its children, assuming |
| 309 | * that they did not change, and then updates all the nodes that may have |
| 310 | * changed in the path to the root. The only nodes that may have changed |
| 311 | * are the ones in the path or their siblings. |
| 312 | */ |
| 313 | static void bfq_update_active_tree(struct rb_node *node) |
| 314 | { |
| 315 | struct rb_node *parent; |
| 316 | |
| 317 | up: |
| 318 | bfq_update_active_node(node); |
| 319 | |
| 320 | parent = rb_parent(node); |
| 321 | if (parent == NULL) |
| 322 | return; |
| 323 | |
| 324 | if (node == parent->rb_left && parent->rb_right != NULL) |
| 325 | bfq_update_active_node(parent->rb_right); |
| 326 | else if (parent->rb_left != NULL) |
| 327 | bfq_update_active_node(parent->rb_left); |
| 328 | |
| 329 | node = parent; |
| 330 | goto up; |
| 331 | } |
| 332 | |
| 333 | static void bfq_weights_tree_add(struct bfq_data *bfqd, |
| 334 | struct bfq_entity *entity, |
| 335 | struct rb_root *root); |
| 336 | |
| 337 | static void bfq_weights_tree_remove(struct bfq_data *bfqd, |
| 338 | struct bfq_entity *entity, |
| 339 | struct rb_root *root); |
| 340 | |
| 341 | |
| 342 | /** |
| 343 | * bfq_active_insert - insert an entity in the active tree of its |
| 344 | * group/device. |
| 345 | * @st: the service tree of the entity. |
| 346 | * @entity: the entity being inserted. |
| 347 | * |
| 348 | * The active tree is ordered by finish time, but an extra key is kept |
| 349 | * per each node, containing the minimum value for the start times of |
| 350 | * its children (and the node itself), so it's possible to search for |
| 351 | * the eligible node with the lowest finish time in logarithmic time. |
| 352 | */ |
| 353 | static void bfq_active_insert(struct bfq_service_tree *st, |
| 354 | struct bfq_entity *entity) |
| 355 | { |
| 356 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 357 | struct rb_node *node = &entity->rb_node; |
| 358 | #ifdef CONFIG_CGROUP_BFQIO |
| 359 | struct bfq_sched_data *sd = NULL; |
| 360 | struct bfq_group *bfqg = NULL; |
| 361 | struct bfq_data *bfqd = NULL; |
| 362 | #endif |
| 363 | |
| 364 | bfq_insert(&st->active, entity); |
| 365 | |
| 366 | if (node->rb_left != NULL) |
| 367 | node = node->rb_left; |
| 368 | else if (node->rb_right != NULL) |
| 369 | node = node->rb_right; |
| 370 | |
| 371 | bfq_update_active_tree(node); |
| 372 | |
| 373 | #ifdef CONFIG_CGROUP_BFQIO |
| 374 | sd = entity->sched_data; |
| 375 | bfqg = container_of(sd, struct bfq_group, sched_data); |
| 376 | BUG_ON(!bfqg); |
| 377 | bfqd = (struct bfq_data *)bfqg->bfqd; |
| 378 | #endif |
| 379 | if (bfqq != NULL) |
| 380 | list_add(&bfqq->bfqq_list, &bfqq->bfqd->active_list); |
| 381 | #ifdef CONFIG_CGROUP_BFQIO |
| 382 | else { /* bfq_group */ |
| 383 | BUG_ON(!bfqd); |
| 384 | bfq_weights_tree_add(bfqd, entity, &bfqd->group_weights_tree); |
| 385 | } |
| 386 | if (bfqg != bfqd->root_group) { |
| 387 | BUG_ON(!bfqg); |
| 388 | BUG_ON(!bfqd); |
| 389 | bfqg->active_entities++; |
| 390 | if (bfqg->active_entities == 2) |
| 391 | bfqd->active_numerous_groups++; |
| 392 | } |
| 393 | #endif |
| 394 | } |
| 395 | |
| 396 | /** |
| 397 | * bfq_ioprio_to_weight - calc a weight from an ioprio. |
| 398 | * @ioprio: the ioprio value to convert. |
| 399 | */ |
| 400 | static inline unsigned short bfq_ioprio_to_weight(int ioprio) |
| 401 | { |
| 402 | BUG_ON(ioprio < 0 || ioprio >= IOPRIO_BE_NR); |
| 403 | return IOPRIO_BE_NR - ioprio; |
| 404 | } |
| 405 | |
| 406 | /** |
| 407 | * bfq_weight_to_ioprio - calc an ioprio from a weight. |
| 408 | * @weight: the weight value to convert. |
| 409 | * |
| 410 | * To preserve as mush as possible the old only-ioprio user interface, |
| 411 | * 0 is used as an escape ioprio value for weights (numerically) equal or |
| 412 | * larger than IOPRIO_BE_NR |
| 413 | */ |
| 414 | static inline unsigned short bfq_weight_to_ioprio(int weight) |
| 415 | { |
| 416 | BUG_ON(weight < BFQ_MIN_WEIGHT || weight > BFQ_MAX_WEIGHT); |
| 417 | return IOPRIO_BE_NR - weight < 0 ? 0 : IOPRIO_BE_NR - weight; |
| 418 | } |
| 419 | |
| 420 | static inline void bfq_get_entity(struct bfq_entity *entity) |
| 421 | { |
| 422 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 423 | |
| 424 | if (bfqq != NULL) { |
| 425 | atomic_inc(&bfqq->ref); |
| 426 | bfq_log_bfqq(bfqq->bfqd, bfqq, "get_entity: %p %d", |
| 427 | bfqq, atomic_read(&bfqq->ref)); |
| 428 | } |
| 429 | } |
| 430 | |
| 431 | /** |
| 432 | * bfq_find_deepest - find the deepest node that an extraction can modify. |
| 433 | * @node: the node being removed. |
| 434 | * |
| 435 | * Do the first step of an extraction in an rb tree, looking for the |
| 436 | * node that will replace @node, and returning the deepest node that |
| 437 | * the following modifications to the tree can touch. If @node is the |
| 438 | * last node in the tree return %NULL. |
| 439 | */ |
| 440 | static struct rb_node *bfq_find_deepest(struct rb_node *node) |
| 441 | { |
| 442 | struct rb_node *deepest; |
| 443 | |
| 444 | if (node->rb_right == NULL && node->rb_left == NULL) |
| 445 | deepest = rb_parent(node); |
| 446 | else if (node->rb_right == NULL) |
| 447 | deepest = node->rb_left; |
| 448 | else if (node->rb_left == NULL) |
| 449 | deepest = node->rb_right; |
| 450 | else { |
| 451 | deepest = rb_next(node); |
| 452 | if (deepest->rb_right != NULL) |
| 453 | deepest = deepest->rb_right; |
| 454 | else if (rb_parent(deepest) != node) |
| 455 | deepest = rb_parent(deepest); |
| 456 | } |
| 457 | |
| 458 | return deepest; |
| 459 | } |
| 460 | |
| 461 | /** |
| 462 | * bfq_active_extract - remove an entity from the active tree. |
| 463 | * @st: the service_tree containing the tree. |
| 464 | * @entity: the entity being removed. |
| 465 | */ |
| 466 | static void bfq_active_extract(struct bfq_service_tree *st, |
| 467 | struct bfq_entity *entity) |
| 468 | { |
| 469 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 470 | struct rb_node *node; |
| 471 | #ifdef CONFIG_CGROUP_BFQIO |
| 472 | struct bfq_sched_data *sd = NULL; |
| 473 | struct bfq_group *bfqg = NULL; |
| 474 | struct bfq_data *bfqd = NULL; |
| 475 | #endif |
| 476 | |
| 477 | node = bfq_find_deepest(&entity->rb_node); |
| 478 | bfq_extract(&st->active, entity); |
| 479 | |
| 480 | if (node != NULL) |
| 481 | bfq_update_active_tree(node); |
| 482 | |
| 483 | #ifdef CONFIG_CGROUP_BFQIO |
| 484 | sd = entity->sched_data; |
| 485 | bfqg = container_of(sd, struct bfq_group, sched_data); |
| 486 | BUG_ON(!bfqg); |
| 487 | bfqd = (struct bfq_data *)bfqg->bfqd; |
| 488 | #endif |
| 489 | if (bfqq != NULL) |
| 490 | list_del(&bfqq->bfqq_list); |
| 491 | #ifdef CONFIG_CGROUP_BFQIO |
| 492 | else { /* bfq_group */ |
| 493 | BUG_ON(!bfqd); |
| 494 | bfq_weights_tree_remove(bfqd, entity, |
| 495 | &bfqd->group_weights_tree); |
| 496 | } |
| 497 | if (bfqg != bfqd->root_group) { |
| 498 | BUG_ON(!bfqg); |
| 499 | BUG_ON(!bfqd); |
| 500 | BUG_ON(!bfqg->active_entities); |
| 501 | bfqg->active_entities--; |
| 502 | if (bfqg->active_entities == 1) { |
| 503 | BUG_ON(!bfqd->active_numerous_groups); |
| 504 | bfqd->active_numerous_groups--; |
| 505 | } |
| 506 | } |
| 507 | #endif |
| 508 | } |
| 509 | |
| 510 | /** |
| 511 | * bfq_idle_insert - insert an entity into the idle tree. |
| 512 | * @st: the service tree containing the tree. |
| 513 | * @entity: the entity to insert. |
| 514 | */ |
| 515 | static void bfq_idle_insert(struct bfq_service_tree *st, |
| 516 | struct bfq_entity *entity) |
| 517 | { |
| 518 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 519 | struct bfq_entity *first_idle = st->first_idle; |
| 520 | struct bfq_entity *last_idle = st->last_idle; |
| 521 | |
| 522 | if (first_idle == NULL || bfq_gt(first_idle->finish, entity->finish)) |
| 523 | st->first_idle = entity; |
| 524 | if (last_idle == NULL || bfq_gt(entity->finish, last_idle->finish)) |
| 525 | st->last_idle = entity; |
| 526 | |
| 527 | bfq_insert(&st->idle, entity); |
| 528 | |
| 529 | if (bfqq != NULL) |
| 530 | list_add(&bfqq->bfqq_list, &bfqq->bfqd->idle_list); |
| 531 | } |
| 532 | |
| 533 | /** |
| 534 | * bfq_forget_entity - remove an entity from the wfq trees. |
| 535 | * @st: the service tree. |
| 536 | * @entity: the entity being removed. |
| 537 | * |
| 538 | * Update the device status and forget everything about @entity, putting |
| 539 | * the device reference to it, if it is a queue. Entities belonging to |
| 540 | * groups are not refcounted. |
| 541 | */ |
| 542 | static void bfq_forget_entity(struct bfq_service_tree *st, |
| 543 | struct bfq_entity *entity) |
| 544 | { |
| 545 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 546 | struct bfq_sched_data *sd; |
| 547 | |
| 548 | BUG_ON(!entity->on_st); |
| 549 | |
| 550 | entity->on_st = 0; |
| 551 | st->wsum -= entity->weight; |
| 552 | if (bfqq != NULL) { |
| 553 | sd = entity->sched_data; |
| 554 | bfq_log_bfqq(bfqq->bfqd, bfqq, "forget_entity: %p %d", |
| 555 | bfqq, atomic_read(&bfqq->ref)); |
| 556 | bfq_put_queue(bfqq); |
| 557 | } |
| 558 | } |
| 559 | |
| 560 | /** |
| 561 | * bfq_put_idle_entity - release the idle tree ref of an entity. |
| 562 | * @st: service tree for the entity. |
| 563 | * @entity: the entity being released. |
| 564 | */ |
| 565 | static void bfq_put_idle_entity(struct bfq_service_tree *st, |
| 566 | struct bfq_entity *entity) |
| 567 | { |
| 568 | bfq_idle_extract(st, entity); |
| 569 | bfq_forget_entity(st, entity); |
| 570 | } |
| 571 | |
| 572 | /** |
| 573 | * bfq_forget_idle - update the idle tree if necessary. |
| 574 | * @st: the service tree to act upon. |
| 575 | * |
| 576 | * To preserve the global O(log N) complexity we only remove one entry here; |
| 577 | * as the idle tree will not grow indefinitely this can be done safely. |
| 578 | */ |
| 579 | static void bfq_forget_idle(struct bfq_service_tree *st) |
| 580 | { |
| 581 | struct bfq_entity *first_idle = st->first_idle; |
| 582 | struct bfq_entity *last_idle = st->last_idle; |
| 583 | |
| 584 | if (RB_EMPTY_ROOT(&st->active) && last_idle != NULL && |
| 585 | !bfq_gt(last_idle->finish, st->vtime)) { |
| 586 | /* |
| 587 | * Forget the whole idle tree, increasing the vtime past |
| 588 | * the last finish time of idle entities. |
| 589 | */ |
| 590 | st->vtime = last_idle->finish; |
| 591 | } |
| 592 | |
| 593 | if (first_idle != NULL && !bfq_gt(first_idle->finish, st->vtime)) |
| 594 | bfq_put_idle_entity(st, first_idle); |
| 595 | } |
| 596 | |
| 597 | static struct bfq_service_tree * |
| 598 | __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st, |
| 599 | struct bfq_entity *entity) |
| 600 | { |
| 601 | struct bfq_service_tree *new_st = old_st; |
| 602 | |
| 603 | if (entity->ioprio_changed) { |
| 604 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
| 605 | unsigned short prev_weight, new_weight; |
| 606 | struct bfq_data *bfqd = NULL; |
| 607 | struct rb_root *root; |
| 608 | #ifdef CONFIG_CGROUP_BFQIO |
| 609 | struct bfq_sched_data *sd; |
| 610 | struct bfq_group *bfqg; |
| 611 | #endif |
| 612 | |
| 613 | if (bfqq != NULL) |
| 614 | bfqd = bfqq->bfqd; |
| 615 | #ifdef CONFIG_CGROUP_BFQIO |
| 616 | else { |
| 617 | sd = entity->my_sched_data; |
| 618 | bfqg = container_of(sd, struct bfq_group, sched_data); |
| 619 | BUG_ON(!bfqg); |
| 620 | bfqd = (struct bfq_data *)bfqg->bfqd; |
| 621 | BUG_ON(!bfqd); |
| 622 | } |
| 623 | #endif |
| 624 | |
| 625 | BUG_ON(old_st->wsum < entity->weight); |
| 626 | old_st->wsum -= entity->weight; |
| 627 | |
| 628 | if (entity->new_weight != entity->orig_weight) { |
| 629 | if (entity->new_weight < BFQ_MIN_WEIGHT || |
| 630 | entity->new_weight > BFQ_MAX_WEIGHT) { |
| 631 | printk(KERN_CRIT "update_weight_prio: " |
| 632 | "new_weight %d\n", |
| 633 | entity->new_weight); |
| 634 | BUG(); |
| 635 | } |
| 636 | entity->orig_weight = entity->new_weight; |
| 637 | entity->ioprio = |
| 638 | bfq_weight_to_ioprio(entity->orig_weight); |
| 639 | } |
| 640 | |
| 641 | entity->ioprio_class = entity->new_ioprio_class; |
| 642 | entity->ioprio_changed = 0; |
| 643 | |
| 644 | /* |
| 645 | * NOTE: here we may be changing the weight too early, |
| 646 | * this will cause unfairness. The correct approach |
| 647 | * would have required additional complexity to defer |
| 648 | * weight changes to the proper time instants (i.e., |
| 649 | * when entity->finish <= old_st->vtime). |
| 650 | */ |
| 651 | new_st = bfq_entity_service_tree(entity); |
| 652 | |
| 653 | prev_weight = entity->weight; |
| 654 | new_weight = entity->orig_weight * |
| 655 | (bfqq != NULL ? bfqq->wr_coeff : 1); |
| 656 | /* |
| 657 | * If the weight of the entity changes, remove the entity |
| 658 | * from its old weight counter (if there is a counter |
| 659 | * associated with the entity), and add it to the counter |
| 660 | * associated with its new weight. |
| 661 | */ |
| 662 | if (prev_weight != new_weight) { |
| 663 | root = bfqq ? &bfqd->queue_weights_tree : |
| 664 | &bfqd->group_weights_tree; |
| 665 | bfq_weights_tree_remove(bfqd, entity, root); |
| 666 | } |
| 667 | entity->weight = new_weight; |
| 668 | /* |
| 669 | * Add the entity to its weights tree only if it is |
| 670 | * not associated with a weight-raised queue. |
| 671 | */ |
| 672 | if (prev_weight != new_weight && |
| 673 | (bfqq ? bfqq->wr_coeff == 1 : 1)) |
| 674 | /* If we get here, root has been initialized. */ |
| 675 | bfq_weights_tree_add(bfqd, entity, root); |
| 676 | |
| 677 | new_st->wsum += entity->weight; |
| 678 | |
| 679 | if (new_st != old_st) |
| 680 | entity->start = new_st->vtime; |
| 681 | } |
| 682 | |
| 683 | return new_st; |
| 684 | } |
| 685 | |
| 686 | /** |
| 687 | * bfq_bfqq_served - update the scheduler status after selection for |
| 688 | * service. |
| 689 | * @bfqq: the queue being served. |
| 690 | * @served: bytes to transfer. |
| 691 | * |
| 692 | * NOTE: this can be optimized, as the timestamps of upper level entities |
| 693 | * are synchronized every time a new bfqq is selected for service. By now, |
| 694 | * we keep it to better check consistency. |
| 695 | */ |
| 696 | static void bfq_bfqq_served(struct bfq_queue *bfqq, unsigned long served) |
| 697 | { |
| 698 | struct bfq_entity *entity = &bfqq->entity; |
| 699 | struct bfq_service_tree *st; |
| 700 | |
| 701 | for_each_entity(entity) { |
| 702 | st = bfq_entity_service_tree(entity); |
| 703 | |
| 704 | entity->service += served; |
| 705 | BUG_ON(entity->service > entity->budget); |
| 706 | BUG_ON(st->wsum == 0); |
| 707 | |
| 708 | st->vtime += bfq_delta(served, st->wsum); |
| 709 | bfq_forget_idle(st); |
| 710 | } |
| 711 | bfq_log_bfqq(bfqq->bfqd, bfqq, "bfqq_served %lu secs", served); |
| 712 | } |
| 713 | |
| 714 | /** |
| 715 | * bfq_bfqq_charge_full_budget - set the service to the entity budget. |
| 716 | * @bfqq: the queue that needs a service update. |
| 717 | * |
| 718 | * When it's not possible to be fair in the service domain, because |
| 719 | * a queue is not consuming its budget fast enough (the meaning of |
| 720 | * fast depends on the timeout parameter), we charge it a full |
| 721 | * budget. In this way we should obtain a sort of time-domain |
| 722 | * fairness among all the seeky/slow queues. |
| 723 | */ |
| 724 | static inline void bfq_bfqq_charge_full_budget(struct bfq_queue *bfqq) |
| 725 | { |
| 726 | struct bfq_entity *entity = &bfqq->entity; |
| 727 | |
| 728 | bfq_log_bfqq(bfqq->bfqd, bfqq, "charge_full_budget"); |
| 729 | |
| 730 | bfq_bfqq_served(bfqq, entity->budget - entity->service); |
| 731 | } |
| 732 | |
| 733 | /** |
| 734 | * __bfq_activate_entity - activate an entity. |
| 735 | * @entity: the entity being activated. |
| 736 | * |
| 737 | * Called whenever an entity is activated, i.e., it is not active and one |
| 738 | * of its children receives a new request, or has to be reactivated due to |
| 739 | * budget exhaustion. It uses the current budget of the entity (and the |
| 740 | * service received if @entity is active) of the queue to calculate its |
| 741 | * timestamps. |
| 742 | */ |
| 743 | static void __bfq_activate_entity(struct bfq_entity *entity) |
| 744 | { |
| 745 | struct bfq_sched_data *sd = entity->sched_data; |
| 746 | struct bfq_service_tree *st = bfq_entity_service_tree(entity); |
| 747 | |
| 748 | if (entity == sd->in_service_entity) { |
| 749 | BUG_ON(entity->tree != NULL); |
| 750 | /* |
| 751 | * If we are requeueing the current entity we have |
| 752 | * to take care of not charging to it service it has |
| 753 | * not received. |
| 754 | */ |
| 755 | bfq_calc_finish(entity, entity->service); |
| 756 | entity->start = entity->finish; |
| 757 | sd->in_service_entity = NULL; |
| 758 | } else if (entity->tree == &st->active) { |
| 759 | /* |
| 760 | * Requeueing an entity due to a change of some |
| 761 | * next_in_service entity below it. We reuse the |
| 762 | * old start time. |
| 763 | */ |
| 764 | bfq_active_extract(st, entity); |
| 765 | } else if (entity->tree == &st->idle) { |
| 766 | /* |
| 767 | * Must be on the idle tree, bfq_idle_extract() will |
| 768 | * check for that. |
| 769 | */ |
| 770 | bfq_idle_extract(st, entity); |
| 771 | entity->start = bfq_gt(st->vtime, entity->finish) ? |
| 772 | st->vtime : entity->finish; |
| 773 | } else { |
| 774 | /* |
| 775 | * The finish time of the entity may be invalid, and |
| 776 | * it is in the past for sure, otherwise the queue |
| 777 | * would have been on the idle tree. |
| 778 | */ |
| 779 | entity->start = st->vtime; |
| 780 | st->wsum += entity->weight; |
| 781 | bfq_get_entity(entity); |
| 782 | |
| 783 | BUG_ON(entity->on_st); |
| 784 | entity->on_st = 1; |
| 785 | } |
| 786 | |
| 787 | st = __bfq_entity_update_weight_prio(st, entity); |
| 788 | bfq_calc_finish(entity, entity->budget); |
| 789 | bfq_active_insert(st, entity); |
| 790 | } |
| 791 | |
| 792 | /** |
| 793 | * bfq_activate_entity - activate an entity and its ancestors if necessary. |
| 794 | * @entity: the entity to activate. |
| 795 | * |
| 796 | * Activate @entity and all the entities on the path from it to the root. |
| 797 | */ |
| 798 | static void bfq_activate_entity(struct bfq_entity *entity) |
| 799 | { |
| 800 | struct bfq_sched_data *sd; |
| 801 | |
| 802 | for_each_entity(entity) { |
| 803 | __bfq_activate_entity(entity); |
| 804 | |
| 805 | sd = entity->sched_data; |
| 806 | if (!bfq_update_next_in_service(sd)) |
| 807 | /* |
| 808 | * No need to propagate the activation to the |
| 809 | * upper entities, as they will be updated when |
| 810 | * the in-service entity is rescheduled. |
| 811 | */ |
| 812 | break; |
| 813 | } |
| 814 | } |
| 815 | |
| 816 | /** |
| 817 | * __bfq_deactivate_entity - deactivate an entity from its service tree. |
| 818 | * @entity: the entity to deactivate. |
| 819 | * @requeue: if false, the entity will not be put into the idle tree. |
| 820 | * |
| 821 | * Deactivate an entity, independently from its previous state. If the |
| 822 | * entity was not on a service tree just return, otherwise if it is on |
| 823 | * any scheduler tree, extract it from that tree, and if necessary |
| 824 | * and if the caller did not specify @requeue, put it on the idle tree. |
| 825 | * |
| 826 | * Return %1 if the caller should update the entity hierarchy, i.e., |
| 827 | * if the entity was in service or if it was the next_in_service for |
| 828 | * its sched_data; return %0 otherwise. |
| 829 | */ |
| 830 | static int __bfq_deactivate_entity(struct bfq_entity *entity, int requeue) |
| 831 | { |
| 832 | struct bfq_sched_data *sd = entity->sched_data; |
| 833 | struct bfq_service_tree *st = bfq_entity_service_tree(entity); |
| 834 | int was_in_service = entity == sd->in_service_entity; |
| 835 | int ret = 0; |
| 836 | |
| 837 | if (!entity->on_st) |
| 838 | return 0; |
| 839 | |
| 840 | BUG_ON(was_in_service && entity->tree != NULL); |
| 841 | |
| 842 | if (was_in_service) { |
| 843 | bfq_calc_finish(entity, entity->service); |
| 844 | sd->in_service_entity = NULL; |
| 845 | } else if (entity->tree == &st->active) |
| 846 | bfq_active_extract(st, entity); |
| 847 | else if (entity->tree == &st->idle) |
| 848 | bfq_idle_extract(st, entity); |
| 849 | else if (entity->tree != NULL) |
| 850 | BUG(); |
| 851 | |
| 852 | if (was_in_service || sd->next_in_service == entity) |
| 853 | ret = bfq_update_next_in_service(sd); |
| 854 | |
| 855 | if (!requeue || !bfq_gt(entity->finish, st->vtime)) |
| 856 | bfq_forget_entity(st, entity); |
| 857 | else |
| 858 | bfq_idle_insert(st, entity); |
| 859 | |
| 860 | BUG_ON(sd->in_service_entity == entity); |
| 861 | BUG_ON(sd->next_in_service == entity); |
| 862 | |
| 863 | return ret; |
| 864 | } |
| 865 | |
| 866 | /** |
| 867 | * bfq_deactivate_entity - deactivate an entity. |
| 868 | * @entity: the entity to deactivate. |
| 869 | * @requeue: true if the entity can be put on the idle tree |
| 870 | */ |
| 871 | static void bfq_deactivate_entity(struct bfq_entity *entity, int requeue) |
| 872 | { |
| 873 | struct bfq_sched_data *sd; |
| 874 | struct bfq_entity *parent; |
| 875 | |
| 876 | for_each_entity_safe(entity, parent) { |
| 877 | sd = entity->sched_data; |
| 878 | |
| 879 | if (!__bfq_deactivate_entity(entity, requeue)) |
| 880 | /* |
| 881 | * The parent entity is still backlogged, and |
| 882 | * we don't need to update it as it is still |
| 883 | * in service. |
| 884 | */ |
| 885 | break; |
| 886 | |
| 887 | if (sd->next_in_service != NULL) |
| 888 | /* |
| 889 | * The parent entity is still backlogged and |
| 890 | * the budgets on the path towards the root |
| 891 | * need to be updated. |
| 892 | */ |
| 893 | goto update; |
| 894 | |
| 895 | /* |
| 896 | * If we reach there the parent is no more backlogged and |
| 897 | * we want to propagate the dequeue upwards. |
| 898 | */ |
| 899 | requeue = 1; |
| 900 | } |
| 901 | |
| 902 | return; |
| 903 | |
| 904 | update: |
| 905 | entity = parent; |
| 906 | for_each_entity(entity) { |
| 907 | __bfq_activate_entity(entity); |
| 908 | |
| 909 | sd = entity->sched_data; |
| 910 | if (!bfq_update_next_in_service(sd)) |
| 911 | break; |
| 912 | } |
| 913 | } |
| 914 | |
| 915 | /** |
| 916 | * bfq_update_vtime - update vtime if necessary. |
| 917 | * @st: the service tree to act upon. |
| 918 | * |
| 919 | * If necessary update the service tree vtime to have at least one |
| 920 | * eligible entity, skipping to its start time. Assumes that the |
| 921 | * active tree of the device is not empty. |
| 922 | * |
| 923 | * NOTE: this hierarchical implementation updates vtimes quite often, |
| 924 | * we may end up with reactivated processes getting timestamps after a |
| 925 | * vtime skip done because we needed a ->first_active entity on some |
| 926 | * intermediate node. |
| 927 | */ |
| 928 | static void bfq_update_vtime(struct bfq_service_tree *st) |
| 929 | { |
| 930 | struct bfq_entity *entry; |
| 931 | struct rb_node *node = st->active.rb_node; |
| 932 | |
| 933 | entry = rb_entry(node, struct bfq_entity, rb_node); |
| 934 | if (bfq_gt(entry->min_start, st->vtime)) { |
| 935 | st->vtime = entry->min_start; |
| 936 | bfq_forget_idle(st); |
| 937 | } |
| 938 | } |
| 939 | |
| 940 | /** |
| 941 | * bfq_first_active_entity - find the eligible entity with |
| 942 | * the smallest finish time |
| 943 | * @st: the service tree to select from. |
| 944 | * |
| 945 | * This function searches the first schedulable entity, starting from the |
| 946 | * root of the tree and going on the left every time on this side there is |
| 947 | * a subtree with at least one eligible (start >= vtime) entity. The path on |
| 948 | * the right is followed only if a) the left subtree contains no eligible |
| 949 | * entities and b) no eligible entity has been found yet. |
| 950 | */ |
| 951 | static struct bfq_entity *bfq_first_active_entity(struct bfq_service_tree *st) |
| 952 | { |
| 953 | struct bfq_entity *entry, *first = NULL; |
| 954 | struct rb_node *node = st->active.rb_node; |
| 955 | |
| 956 | while (node != NULL) { |
| 957 | entry = rb_entry(node, struct bfq_entity, rb_node); |
| 958 | left: |
| 959 | if (!bfq_gt(entry->start, st->vtime)) |
| 960 | first = entry; |
| 961 | |
| 962 | BUG_ON(bfq_gt(entry->min_start, st->vtime)); |
| 963 | |
| 964 | if (node->rb_left != NULL) { |
| 965 | entry = rb_entry(node->rb_left, |
| 966 | struct bfq_entity, rb_node); |
| 967 | if (!bfq_gt(entry->min_start, st->vtime)) { |
| 968 | node = node->rb_left; |
| 969 | goto left; |
| 970 | } |
| 971 | } |
| 972 | if (first != NULL) |
| 973 | break; |
| 974 | node = node->rb_right; |
| 975 | } |
| 976 | |
| 977 | BUG_ON(first == NULL && !RB_EMPTY_ROOT(&st->active)); |
| 978 | return first; |
| 979 | } |
| 980 | |
| 981 | /** |
| 982 | * __bfq_lookup_next_entity - return the first eligible entity in @st. |
| 983 | * @st: the service tree. |
| 984 | * |
| 985 | * Update the virtual time in @st and return the first eligible entity |
| 986 | * it contains. |
| 987 | */ |
| 988 | static struct bfq_entity *__bfq_lookup_next_entity(struct bfq_service_tree *st, |
| 989 | bool force) |
| 990 | { |
| 991 | struct bfq_entity *entity, *new_next_in_service = NULL; |
| 992 | |
| 993 | if (RB_EMPTY_ROOT(&st->active)) |
| 994 | return NULL; |
| 995 | |
| 996 | bfq_update_vtime(st); |
| 997 | entity = bfq_first_active_entity(st); |
| 998 | BUG_ON(bfq_gt(entity->start, st->vtime)); |
| 999 | |
| 1000 | /* |
| 1001 | * If the chosen entity does not match with the sched_data's |
| 1002 | * next_in_service and we are forcedly serving the IDLE priority |
| 1003 | * class tree, bubble up budget update. |
| 1004 | */ |
| 1005 | if (unlikely(force && entity != entity->sched_data->next_in_service)) { |
| 1006 | new_next_in_service = entity; |
| 1007 | for_each_entity(new_next_in_service) |
| 1008 | bfq_update_budget(new_next_in_service); |
| 1009 | } |
| 1010 | |
| 1011 | return entity; |
| 1012 | } |
| 1013 | |
| 1014 | /** |
| 1015 | * bfq_lookup_next_entity - return the first eligible entity in @sd. |
| 1016 | * @sd: the sched_data. |
| 1017 | * @extract: if true the returned entity will be also extracted from @sd. |
| 1018 | * |
| 1019 | * NOTE: since we cache the next_in_service entity at each level of the |
| 1020 | * hierarchy, the complexity of the lookup can be decreased with |
| 1021 | * absolutely no effort just returning the cached next_in_service value; |
| 1022 | * we prefer to do full lookups to test the consistency of * the data |
| 1023 | * structures. |
| 1024 | */ |
| 1025 | static struct bfq_entity *bfq_lookup_next_entity(struct bfq_sched_data *sd, |
| 1026 | int extract, |
| 1027 | struct bfq_data *bfqd) |
| 1028 | { |
| 1029 | struct bfq_service_tree *st = sd->service_tree; |
| 1030 | struct bfq_entity *entity; |
| 1031 | int i = 0; |
| 1032 | |
| 1033 | BUG_ON(sd->in_service_entity != NULL); |
| 1034 | |
| 1035 | if (bfqd != NULL && |
| 1036 | jiffies - bfqd->bfq_class_idle_last_service > BFQ_CL_IDLE_TIMEOUT) { |
| 1037 | entity = __bfq_lookup_next_entity(st + BFQ_IOPRIO_CLASSES - 1, |
| 1038 | true); |
| 1039 | if (entity != NULL) { |
| 1040 | i = BFQ_IOPRIO_CLASSES - 1; |
| 1041 | bfqd->bfq_class_idle_last_service = jiffies; |
| 1042 | sd->next_in_service = entity; |
| 1043 | } |
| 1044 | } |
| 1045 | for (; i < BFQ_IOPRIO_CLASSES; i++) { |
| 1046 | entity = __bfq_lookup_next_entity(st + i, false); |
| 1047 | if (entity != NULL) { |
| 1048 | if (extract) { |
Diogo Ferreira | 8c73c36 | 2016-11-23 14:46:50 +0000 | [diff] [blame] | 1049 | if (sd->next_in_service != entity) { |
| 1050 | entity = __bfq_lookup_next_entity(st + i, true); |
| 1051 | } |
Paolo Valente | 70f2871 | 2013-05-09 19:10:02 +0200 | [diff] [blame] | 1052 | bfq_check_next_in_service(sd, entity); |
| 1053 | bfq_active_extract(st + i, entity); |
| 1054 | sd->in_service_entity = entity; |
| 1055 | sd->next_in_service = NULL; |
| 1056 | } |
| 1057 | break; |
| 1058 | } |
| 1059 | } |
| 1060 | |
| 1061 | return entity; |
| 1062 | } |
| 1063 | |
| 1064 | /* |
| 1065 | * Get next queue for service. |
| 1066 | */ |
| 1067 | static struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd) |
| 1068 | { |
| 1069 | struct bfq_entity *entity = NULL; |
| 1070 | struct bfq_sched_data *sd; |
| 1071 | struct bfq_queue *bfqq; |
| 1072 | |
| 1073 | BUG_ON(bfqd->in_service_queue != NULL); |
| 1074 | |
| 1075 | if (bfqd->busy_queues == 0) |
| 1076 | return NULL; |
| 1077 | |
| 1078 | sd = &bfqd->root_group->sched_data; |
| 1079 | for (; sd != NULL; sd = entity->my_sched_data) { |
| 1080 | entity = bfq_lookup_next_entity(sd, 1, bfqd); |
| 1081 | BUG_ON(entity == NULL); |
| 1082 | entity->service = 0; |
| 1083 | } |
| 1084 | |
| 1085 | bfqq = bfq_entity_to_bfqq(entity); |
| 1086 | BUG_ON(bfqq == NULL); |
| 1087 | |
| 1088 | return bfqq; |
| 1089 | } |
| 1090 | |
Paolo Valente | 70f2871 | 2013-05-09 19:10:02 +0200 | [diff] [blame] | 1091 | static void __bfq_bfqd_reset_in_service(struct bfq_data *bfqd) |
| 1092 | { |
| 1093 | if (bfqd->in_service_bic != NULL) { |
| 1094 | put_io_context(bfqd->in_service_bic->icq.ioc); |
| 1095 | bfqd->in_service_bic = NULL; |
| 1096 | } |
| 1097 | |
| 1098 | bfqd->in_service_queue = NULL; |
| 1099 | del_timer(&bfqd->idle_slice_timer); |
| 1100 | } |
| 1101 | |
| 1102 | static void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
| 1103 | int requeue) |
| 1104 | { |
| 1105 | struct bfq_entity *entity = &bfqq->entity; |
| 1106 | |
| 1107 | if (bfqq == bfqd->in_service_queue) |
| 1108 | __bfq_bfqd_reset_in_service(bfqd); |
| 1109 | |
| 1110 | bfq_deactivate_entity(entity, requeue); |
| 1111 | } |
| 1112 | |
| 1113 | static void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq) |
| 1114 | { |
| 1115 | struct bfq_entity *entity = &bfqq->entity; |
| 1116 | |
| 1117 | bfq_activate_entity(entity); |
| 1118 | } |
| 1119 | |
| 1120 | /* |
| 1121 | * Called when the bfqq no longer has requests pending, remove it from |
| 1122 | * the service tree. |
| 1123 | */ |
| 1124 | static void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
| 1125 | int requeue) |
| 1126 | { |
| 1127 | BUG_ON(!bfq_bfqq_busy(bfqq)); |
| 1128 | BUG_ON(!RB_EMPTY_ROOT(&bfqq->sort_list)); |
| 1129 | |
| 1130 | bfq_log_bfqq(bfqd, bfqq, "del from busy"); |
| 1131 | |
| 1132 | bfq_clear_bfqq_busy(bfqq); |
| 1133 | |
| 1134 | BUG_ON(bfqd->busy_queues == 0); |
| 1135 | bfqd->busy_queues--; |
| 1136 | |
| 1137 | if (!bfqq->dispatched) { |
| 1138 | bfq_weights_tree_remove(bfqd, &bfqq->entity, |
| 1139 | &bfqd->queue_weights_tree); |
| 1140 | if (!blk_queue_nonrot(bfqd->queue)) { |
| 1141 | BUG_ON(!bfqd->busy_in_flight_queues); |
| 1142 | bfqd->busy_in_flight_queues--; |
| 1143 | if (bfq_bfqq_constantly_seeky(bfqq)) { |
| 1144 | BUG_ON(!bfqd-> |
| 1145 | const_seeky_busy_in_flight_queues); |
| 1146 | bfqd->const_seeky_busy_in_flight_queues--; |
| 1147 | } |
| 1148 | } |
| 1149 | } |
| 1150 | if (bfqq->wr_coeff > 1) |
| 1151 | bfqd->wr_busy_queues--; |
| 1152 | |
| 1153 | bfq_deactivate_bfqq(bfqd, bfqq, requeue); |
| 1154 | } |
| 1155 | |
| 1156 | /* |
| 1157 | * Called when an inactive queue receives a new request. |
| 1158 | */ |
| 1159 | static void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq) |
| 1160 | { |
| 1161 | BUG_ON(bfq_bfqq_busy(bfqq)); |
| 1162 | BUG_ON(bfqq == bfqd->in_service_queue); |
| 1163 | |
| 1164 | bfq_log_bfqq(bfqd, bfqq, "add to busy"); |
| 1165 | |
| 1166 | bfq_activate_bfqq(bfqd, bfqq); |
| 1167 | |
| 1168 | bfq_mark_bfqq_busy(bfqq); |
| 1169 | bfqd->busy_queues++; |
| 1170 | |
| 1171 | if (!bfqq->dispatched) { |
| 1172 | if (bfqq->wr_coeff == 1) |
| 1173 | bfq_weights_tree_add(bfqd, &bfqq->entity, |
| 1174 | &bfqd->queue_weights_tree); |
| 1175 | if (!blk_queue_nonrot(bfqd->queue)) { |
| 1176 | bfqd->busy_in_flight_queues++; |
| 1177 | if (bfq_bfqq_constantly_seeky(bfqq)) |
| 1178 | bfqd->const_seeky_busy_in_flight_queues++; |
| 1179 | } |
| 1180 | } |
| 1181 | if (bfqq->wr_coeff > 1) |
| 1182 | bfqd->wr_busy_queues++; |
| 1183 | } |