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a497ee34 | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
ea25da48 PV |
2 | /* |
3 | * Header file for the BFQ I/O scheduler: data structures and | |
4 | * prototypes of interface functions among BFQ components. | |
ea25da48 PV |
5 | */ |
6 | #ifndef _BFQ_H | |
7 | #define _BFQ_H | |
8 | ||
9 | #include <linux/blktrace_api.h> | |
10 | #include <linux/hrtimer.h> | |
ea25da48 | 11 | |
1d156646 TH |
12 | #include "blk-cgroup-rwstat.h" |
13 | ||
ea25da48 PV |
14 | #define BFQ_IOPRIO_CLASSES 3 |
15 | #define BFQ_CL_IDLE_TIMEOUT (HZ/5) | |
16 | ||
17 | #define BFQ_MIN_WEIGHT 1 | |
18 | #define BFQ_MAX_WEIGHT 1000 | |
19 | #define BFQ_WEIGHT_CONVERSION_COEFF 10 | |
20 | ||
21 | #define BFQ_DEFAULT_QUEUE_IOPRIO 4 | |
22 | ||
23 | #define BFQ_WEIGHT_LEGACY_DFL 100 | |
24 | #define BFQ_DEFAULT_GRP_IOPRIO 0 | |
25 | #define BFQ_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE | |
26 | ||
582f04e1 | 27 | #define MAX_BFQQ_NAME_LENGTH 16 |
1e66413c | 28 | |
ea25da48 PV |
29 | /* |
30 | * Soft real-time applications are extremely more latency sensitive | |
31 | * than interactive ones. Over-raise the weight of the former to | |
32 | * privilege them against the latter. | |
33 | */ | |
34 | #define BFQ_SOFTRT_WEIGHT_FACTOR 100 | |
35 | ||
36 | struct bfq_entity; | |
37 | ||
38 | /** | |
39 | * struct bfq_service_tree - per ioprio_class service tree. | |
40 | * | |
41 | * Each service tree represents a B-WF2Q+ scheduler on its own. Each | |
42 | * ioprio_class has its own independent scheduler, and so its own | |
43 | * bfq_service_tree. All the fields are protected by the queue lock | |
44 | * of the containing bfqd. | |
45 | */ | |
46 | struct bfq_service_tree { | |
47 | /* tree for active entities (i.e., those backlogged) */ | |
48 | struct rb_root active; | |
38c91407 | 49 | /* tree for idle entities (i.e., not backlogged, with V < F_i)*/ |
ea25da48 PV |
50 | struct rb_root idle; |
51 | ||
52 | /* idle entity with minimum F_i */ | |
53 | struct bfq_entity *first_idle; | |
54 | /* idle entity with maximum F_i */ | |
55 | struct bfq_entity *last_idle; | |
56 | ||
57 | /* scheduler virtual time */ | |
58 | u64 vtime; | |
59 | /* scheduler weight sum; active and idle entities contribute to it */ | |
60 | unsigned long wsum; | |
61 | }; | |
62 | ||
63 | /** | |
64 | * struct bfq_sched_data - multi-class scheduler. | |
65 | * | |
66 | * bfq_sched_data is the basic scheduler queue. It supports three | |
67 | * ioprio_classes, and can be used either as a toplevel queue or as an | |
46d556e6 | 68 | * intermediate queue in a hierarchical setup. |
ea25da48 PV |
69 | * |
70 | * The supported ioprio_classes are the same as in CFQ, in descending | |
71 | * priority order, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE. | |
72 | * Requests from higher priority queues are served before all the | |
73 | * requests from lower priority queues; among requests of the same | |
74 | * queue requests are served according to B-WF2Q+. | |
46d556e6 PV |
75 | * |
76 | * The schedule is implemented by the service trees, plus the field | |
77 | * @next_in_service, which points to the entity on the active trees | |
78 | * that will be served next, if 1) no changes in the schedule occurs | |
79 | * before the current in-service entity is expired, 2) the in-service | |
80 | * queue becomes idle when it expires, and 3) if the entity pointed by | |
81 | * in_service_entity is not a queue, then the in-service child entity | |
82 | * of the entity pointed by in_service_entity becomes idle on | |
83 | * expiration. This peculiar definition allows for the following | |
84 | * optimization, not yet exploited: while a given entity is still in | |
85 | * service, we already know which is the best candidate for next | |
636b8fe8 | 86 | * service among the other active entities in the same parent |
46d556e6 PV |
87 | * entity. We can then quickly compare the timestamps of the |
88 | * in-service entity with those of such best candidate. | |
89 | * | |
90 | * All fields are protected by the lock of the containing bfqd. | |
ea25da48 PV |
91 | */ |
92 | struct bfq_sched_data { | |
93 | /* entity in service */ | |
94 | struct bfq_entity *in_service_entity; | |
95 | /* head-of-line entity (see comments above) */ | |
96 | struct bfq_entity *next_in_service; | |
97 | /* array of service trees, one per ioprio_class */ | |
98 | struct bfq_service_tree service_tree[BFQ_IOPRIO_CLASSES]; | |
99 | /* last time CLASS_IDLE was served */ | |
100 | unsigned long bfq_class_idle_last_service; | |
101 | ||
102 | }; | |
103 | ||
104 | /** | |
2d29c9f8 | 105 | * struct bfq_weight_counter - counter of the number of all active queues |
ea25da48 PV |
106 | * with a given weight. |
107 | */ | |
108 | struct bfq_weight_counter { | |
2d29c9f8 FM |
109 | unsigned int weight; /* weight of the queues this counter refers to */ |
110 | unsigned int num_active; /* nr of active queues with this weight */ | |
ea25da48 | 111 | /* |
2d29c9f8 | 112 | * Weights tree member (see bfq_data's @queue_weights_tree) |
ea25da48 PV |
113 | */ |
114 | struct rb_node weights_node; | |
115 | }; | |
116 | ||
117 | /** | |
118 | * struct bfq_entity - schedulable entity. | |
119 | * | |
120 | * A bfq_entity is used to represent either a bfq_queue (leaf node in the | |
121 | * cgroup hierarchy) or a bfq_group into the upper level scheduler. Each | |
122 | * entity belongs to the sched_data of the parent group in the cgroup | |
123 | * hierarchy. Non-leaf entities have also their own sched_data, stored | |
124 | * in @my_sched_data. | |
125 | * | |
126 | * Each entity stores independently its priority values; this would | |
127 | * allow different weights on different devices, but this | |
128 | * functionality is not exported to userspace by now. Priorities and | |
129 | * weights are updated lazily, first storing the new values into the | |
130 | * new_* fields, then setting the @prio_changed flag. As soon as | |
131 | * there is a transition in the entity state that allows the priority | |
132 | * update to take place the effective and the requested priority | |
133 | * values are synchronized. | |
134 | * | |
135 | * Unless cgroups are used, the weight value is calculated from the | |
136 | * ioprio to export the same interface as CFQ. When dealing with | |
636b8fe8 | 137 | * "well-behaved" queues (i.e., queues that do not spend too much |
ea25da48 PV |
138 | * time to consume their budget and have true sequential behavior, and |
139 | * when there are no external factors breaking anticipation) the | |
140 | * relative weights at each level of the cgroups hierarchy should be | |
141 | * guaranteed. All the fields are protected by the queue lock of the | |
142 | * containing bfqd. | |
143 | */ | |
144 | struct bfq_entity { | |
145 | /* service_tree member */ | |
146 | struct rb_node rb_node; | |
ea25da48 PV |
147 | |
148 | /* | |
149 | * Flag, true if the entity is on a tree (either the active or | |
150 | * the idle one of its service_tree) or is in service. | |
151 | */ | |
33a16a98 | 152 | bool on_st_or_in_serv; |
ea25da48 PV |
153 | |
154 | /* B-WF2Q+ start and finish timestamps [sectors/weight] */ | |
155 | u64 start, finish; | |
156 | ||
157 | /* tree the entity is enqueued into; %NULL if not on a tree */ | |
158 | struct rb_root *tree; | |
159 | ||
160 | /* | |
161 | * minimum start time of the (active) subtree rooted at this | |
162 | * entity; used for O(log N) lookups into active trees | |
163 | */ | |
164 | u64 min_start; | |
165 | ||
166 | /* amount of service received during the last service slot */ | |
167 | int service; | |
168 | ||
169 | /* budget, used also to calculate F_i: F_i = S_i + @budget / @weight */ | |
170 | int budget; | |
171 | ||
98f04499 JK |
172 | /* Number of requests allocated in the subtree of this entity */ |
173 | int allocated; | |
174 | ||
795fe54c FZ |
175 | /* device weight, if non-zero, it overrides the default weight of |
176 | * bfq_group_data */ | |
177 | int dev_weight; | |
ea25da48 PV |
178 | /* weight of the queue */ |
179 | int weight; | |
180 | /* next weight if a change is in progress */ | |
181 | int new_weight; | |
182 | ||
183 | /* original weight, used to implement weight boosting */ | |
184 | int orig_weight; | |
185 | ||
186 | /* parent entity, for hierarchical scheduling */ | |
187 | struct bfq_entity *parent; | |
188 | ||
189 | /* | |
190 | * For non-leaf nodes in the hierarchy, the associated | |
191 | * scheduler queue, %NULL on leaf nodes. | |
192 | */ | |
193 | struct bfq_sched_data *my_sched_data; | |
194 | /* the scheduler queue this entity belongs to */ | |
195 | struct bfq_sched_data *sched_data; | |
196 | ||
197 | /* flag, set to request a weight, ioprio or ioprio_class change */ | |
198 | int prio_changed; | |
ba7aeae5 PV |
199 | |
200 | /* flag, set if the entity is counted in groups_with_pending_reqs */ | |
201 | bool in_groups_with_pending_reqs; | |
430a67f9 PV |
202 | |
203 | /* last child queue of entity created (for non-leaf entities) */ | |
204 | struct bfq_queue *last_bfqq_created; | |
ea25da48 PV |
205 | }; |
206 | ||
207 | struct bfq_group; | |
208 | ||
209 | /** | |
210 | * struct bfq_ttime - per process thinktime stats. | |
211 | */ | |
212 | struct bfq_ttime { | |
213 | /* completion time of the last request */ | |
214 | u64 last_end_request; | |
215 | ||
216 | /* total process thinktime */ | |
217 | u64 ttime_total; | |
218 | /* number of thinktime samples */ | |
219 | unsigned long ttime_samples; | |
220 | /* average process thinktime */ | |
221 | u64 ttime_mean; | |
222 | }; | |
223 | ||
224 | /** | |
225 | * struct bfq_queue - leaf schedulable entity. | |
226 | * | |
227 | * A bfq_queue is a leaf request queue; it can be associated with an | |
228 | * io_context or more, if it is async or shared between cooperating | |
229 | * processes. @cgroup holds a reference to the cgroup, to be sure that it | |
230 | * does not disappear while a bfqq still references it (mostly to avoid | |
231 | * races between request issuing and task migration followed by cgroup | |
232 | * destruction). | |
233 | * All the fields are protected by the queue lock of the containing bfqd. | |
234 | */ | |
235 | struct bfq_queue { | |
236 | /* reference counter */ | |
237 | int ref; | |
430a67f9 PV |
238 | /* counter of references from other queues for delayed stable merge */ |
239 | int stable_ref; | |
ea25da48 PV |
240 | /* parent bfq_data */ |
241 | struct bfq_data *bfqd; | |
242 | ||
243 | /* current ioprio and ioprio class */ | |
244 | unsigned short ioprio, ioprio_class; | |
245 | /* next ioprio and ioprio class if a change is in progress */ | |
246 | unsigned short new_ioprio, new_ioprio_class; | |
247 | ||
2341d662 PV |
248 | /* last total-service-time sample, see bfq_update_inject_limit() */ |
249 | u64 last_serv_time_ns; | |
250 | /* limit for request injection */ | |
251 | unsigned int inject_limit; | |
252 | /* last time the inject limit has been decreased, in jiffies */ | |
253 | unsigned long decrease_time_jif; | |
254 | ||
ea25da48 PV |
255 | /* |
256 | * Shared bfq_queue if queue is cooperating with one or more | |
257 | * other queues. | |
258 | */ | |
259 | struct bfq_queue *new_bfqq; | |
260 | /* request-position tree member (see bfq_group's @rq_pos_tree) */ | |
261 | struct rb_node pos_node; | |
262 | /* request-position tree root (see bfq_group's @rq_pos_tree) */ | |
263 | struct rb_root *pos_root; | |
264 | ||
265 | /* sorted list of pending requests */ | |
266 | struct rb_root sort_list; | |
267 | /* if fifo isn't expired, next request to serve */ | |
268 | struct request *next_rq; | |
269 | /* number of sync and async requests queued */ | |
270 | int queued[2]; | |
ea25da48 PV |
271 | /* number of pending metadata requests */ |
272 | int meta_pending; | |
273 | /* fifo list of requests in sort_list */ | |
274 | struct list_head fifo; | |
275 | ||
276 | /* entity representing this queue in the scheduler */ | |
277 | struct bfq_entity entity; | |
278 | ||
2d29c9f8 FM |
279 | /* pointer to the weight counter associated with this entity */ |
280 | struct bfq_weight_counter *weight_counter; | |
281 | ||
ea25da48 PV |
282 | /* maximum budget allowed from the feedback mechanism */ |
283 | int max_budget; | |
284 | /* budget expiration (in jiffies) */ | |
285 | unsigned long budget_timeout; | |
286 | ||
287 | /* number of requests on the dispatch list or inside driver */ | |
288 | int dispatched; | |
289 | ||
290 | /* status flags */ | |
291 | unsigned long flags; | |
292 | ||
293 | /* node for active/idle bfqq list inside parent bfqd */ | |
294 | struct list_head bfqq_list; | |
295 | ||
296 | /* associated @bfq_ttime struct */ | |
297 | struct bfq_ttime ttime; | |
298 | ||
eb2fd80f PV |
299 | /* when bfqq started to do I/O within the last observation window */ |
300 | u64 io_start_time; | |
301 | /* how long bfqq has remained empty during the last observ. window */ | |
302 | u64 tot_idle_time; | |
303 | ||
ea25da48 PV |
304 | /* bit vector: a 1 for each seeky requests in history */ |
305 | u32 seek_history; | |
306 | ||
307 | /* node for the device's burst list */ | |
308 | struct hlist_node burst_list_node; | |
309 | ||
310 | /* position of the last request enqueued */ | |
311 | sector_t last_request_pos; | |
312 | ||
313 | /* Number of consecutive pairs of request completion and | |
314 | * arrival, such that the queue becomes idle after the | |
315 | * completion, but the next request arrives within an idle | |
316 | * time slice; used only if the queue's IO_bound flag has been | |
317 | * cleared. | |
318 | */ | |
319 | unsigned int requests_within_timer; | |
320 | ||
321 | /* pid of the process owning the queue, used for logging purposes */ | |
322 | pid_t pid; | |
323 | ||
324 | /* | |
325 | * Pointer to the bfq_io_cq owning the bfq_queue, set to %NULL | |
326 | * if the queue is shared. | |
327 | */ | |
328 | struct bfq_io_cq *bic; | |
329 | ||
330 | /* current maximum weight-raising time for this queue */ | |
331 | unsigned long wr_cur_max_time; | |
332 | /* | |
333 | * Minimum time instant such that, only if a new request is | |
334 | * enqueued after this time instant in an idle @bfq_queue with | |
335 | * no outstanding requests, then the task associated with the | |
336 | * queue it is deemed as soft real-time (see the comments on | |
337 | * the function bfq_bfqq_softrt_next_start()) | |
338 | */ | |
339 | unsigned long soft_rt_next_start; | |
340 | /* | |
341 | * Start time of the current weight-raising period if | |
342 | * the @bfq-queue is being weight-raised, otherwise | |
343 | * finish time of the last weight-raising period. | |
344 | */ | |
345 | unsigned long last_wr_start_finish; | |
346 | /* factor by which the weight of this queue is multiplied */ | |
347 | unsigned int wr_coeff; | |
348 | /* | |
349 | * Time of the last transition of the @bfq_queue from idle to | |
350 | * backlogged. | |
351 | */ | |
352 | unsigned long last_idle_bklogged; | |
353 | /* | |
354 | * Cumulative service received from the @bfq_queue since the | |
355 | * last transition from idle to backlogged. | |
356 | */ | |
357 | unsigned long service_from_backlogged; | |
8a8747dc PV |
358 | /* |
359 | * Cumulative service received from the @bfq_queue since its | |
360 | * last transition to weight-raised state. | |
361 | */ | |
362 | unsigned long service_from_wr; | |
ea25da48 PV |
363 | |
364 | /* | |
365 | * Value of wr start time when switching to soft rt | |
366 | */ | |
367 | unsigned long wr_start_at_switch_to_srt; | |
368 | ||
369 | unsigned long split_time; /* time of last split */ | |
7b8fa3b9 PV |
370 | |
371 | unsigned long first_IO_time; /* time of first I/O for this queue */ | |
d0edc247 | 372 | |
430a67f9 PV |
373 | unsigned long creation_time; /* when this queue is created */ |
374 | ||
d0edc247 PV |
375 | /* max service rate measured so far */ |
376 | u32 max_service_rate; | |
13a857a4 PV |
377 | |
378 | /* | |
379 | * Pointer to the waker queue for this queue, i.e., to the | |
380 | * queue Q such that this queue happens to get new I/O right | |
381 | * after some I/O request of Q is completed. For details, see | |
382 | * the comments on the choice of the queue for injection in | |
383 | * bfq_select_queue(). | |
384 | */ | |
385 | struct bfq_queue *waker_bfqq; | |
71217df3 PV |
386 | /* pointer to the curr. tentative waker queue, see bfq_check_waker() */ |
387 | struct bfq_queue *tentative_waker_bfqq; | |
388 | /* number of times the same tentative waker has been detected */ | |
389 | unsigned int num_waker_detections; | |
1f18b700 JK |
390 | /* time when we started considering this waker */ |
391 | u64 waker_detection_started; | |
71217df3 | 392 | |
13a857a4 PV |
393 | /* node for woken_list, see below */ |
394 | struct hlist_node woken_list_node; | |
395 | /* | |
396 | * Head of the list of the woken queues for this queue, i.e., | |
397 | * of the list of the queues for which this queue is a waker | |
398 | * queue. This list is used to reset the waker_bfqq pointer in | |
399 | * the woken queues when this queue exits. | |
400 | */ | |
401 | struct hlist_head woken_list; | |
ea25da48 PV |
402 | }; |
403 | ||
404 | /** | |
405 | * struct bfq_io_cq - per (request_queue, io_context) structure. | |
406 | */ | |
407 | struct bfq_io_cq { | |
408 | /* associated io_cq structure */ | |
409 | struct io_cq icq; /* must be the first member */ | |
410 | /* array of two process queues, the sync and the async */ | |
411 | struct bfq_queue *bfqq[2]; | |
412 | /* per (request_queue, blkcg) ioprio */ | |
413 | int ioprio; | |
414 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
415 | uint64_t blkcg_serial_nr; /* the current blkcg serial */ | |
416 | #endif | |
417 | /* | |
d5be3fef PV |
418 | * Snapshot of the has_short_time flag before merging; taken |
419 | * to remember its value while the queue is merged, so as to | |
420 | * be able to restore it in case of split. | |
ea25da48 | 421 | */ |
d5be3fef | 422 | bool saved_has_short_ttime; |
ea25da48 PV |
423 | /* |
424 | * Same purpose as the previous two fields for the I/O bound | |
425 | * classification of a queue. | |
426 | */ | |
427 | bool saved_IO_bound; | |
428 | ||
eb2fd80f PV |
429 | u64 saved_io_start_time; |
430 | u64 saved_tot_idle_time; | |
431 | ||
ea25da48 PV |
432 | /* |
433 | * Same purpose as the previous fields for the value of the | |
434 | * field keeping the queue's belonging to a large burst | |
435 | */ | |
436 | bool saved_in_large_burst; | |
437 | /* | |
438 | * True if the queue belonged to a burst list before its merge | |
439 | * with another cooperating queue. | |
440 | */ | |
441 | bool was_in_burst_list; | |
442 | ||
fffca087 FP |
443 | /* |
444 | * Save the weight when a merge occurs, to be able | |
445 | * to restore it in case of split. If the weight is not | |
446 | * correctly resumed when the queue is recycled, | |
447 | * then the weight of the recycled queue could differ | |
448 | * from the weight of the original queue. | |
449 | */ | |
450 | unsigned int saved_weight; | |
451 | ||
ea25da48 PV |
452 | /* |
453 | * Similar to previous fields: save wr information. | |
454 | */ | |
455 | unsigned long saved_wr_coeff; | |
456 | unsigned long saved_last_wr_start_finish; | |
e673914d | 457 | unsigned long saved_service_from_wr; |
ea25da48 PV |
458 | unsigned long saved_wr_start_at_switch_to_srt; |
459 | unsigned int saved_wr_cur_max_time; | |
460 | struct bfq_ttime saved_ttime; | |
5a5436b9 PV |
461 | |
462 | /* Save also injection state */ | |
463 | u64 saved_last_serv_time_ns; | |
464 | unsigned int saved_inject_limit; | |
465 | unsigned long saved_decrease_time_jif; | |
430a67f9 PV |
466 | |
467 | /* candidate queue for a stable merge (due to close creation time) */ | |
468 | struct bfq_queue *stable_merge_bfqq; | |
469 | ||
470 | bool stably_merged; /* non splittable if true */ | |
ea25da48 PV |
471 | }; |
472 | ||
ea25da48 PV |
473 | /** |
474 | * struct bfq_data - per-device data structure. | |
475 | * | |
476 | * All the fields are protected by @lock. | |
477 | */ | |
478 | struct bfq_data { | |
479 | /* device request queue */ | |
480 | struct request_queue *queue; | |
481 | /* dispatch queue */ | |
482 | struct list_head dispatch; | |
483 | ||
484 | /* root bfq_group for the device */ | |
485 | struct bfq_group *root_group; | |
486 | ||
487 | /* | |
488 | * rbtree of weight counters of @bfq_queues, sorted by | |
489 | * weight. Used to keep track of whether all @bfq_queues have | |
490 | * the same weight. The tree contains one counter for each | |
491 | * distinct weight associated to some active and not | |
492 | * weight-raised @bfq_queue (see the comments to the functions | |
493 | * bfq_weights_tree_[add|remove] for further details). | |
494 | */ | |
fb53ac6c | 495 | struct rb_root_cached queue_weights_tree; |
ba7aeae5 | 496 | |
ea25da48 | 497 | /* |
ba7aeae5 PV |
498 | * Number of groups with at least one descendant process that |
499 | * has at least one request waiting for completion. Note that | |
500 | * this accounts for also requests already dispatched, but not | |
501 | * yet completed. Therefore this number of groups may differ | |
502 | * (be larger) than the number of active groups, as a group is | |
503 | * considered active only if its corresponding entity has | |
504 | * descendant queues with at least one request queued. This | |
505 | * number is used to decide whether a scenario is symmetric. | |
506 | * For a detailed explanation see comments on the computation | |
507 | * of the variable asymmetric_scenario in the function | |
508 | * bfq_better_to_idle(). | |
509 | * | |
510 | * However, it is hard to compute this number exactly, for | |
511 | * groups with multiple descendant processes. Consider a group | |
512 | * that is inactive, i.e., that has no descendant process with | |
513 | * pending I/O inside BFQ queues. Then suppose that | |
514 | * num_groups_with_pending_reqs is still accounting for this | |
515 | * group, because the group has descendant processes with some | |
516 | * I/O request still in flight. num_groups_with_pending_reqs | |
517 | * should be decremented when the in-flight request of the | |
518 | * last descendant process is finally completed (assuming that | |
519 | * nothing else has changed for the group in the meantime, in | |
520 | * terms of composition of the group and active/inactive state of child | |
521 | * groups and processes). To accomplish this, an additional | |
522 | * pending-request counter must be added to entities, and must | |
523 | * be updated correctly. To avoid this additional field and operations, | |
524 | * we resort to the following tradeoff between simplicity and | |
525 | * accuracy: for an inactive group that is still counted in | |
526 | * num_groups_with_pending_reqs, we decrement | |
527 | * num_groups_with_pending_reqs when the first descendant | |
528 | * process of the group remains with no request waiting for | |
529 | * completion. | |
530 | * | |
531 | * Even this simpler decrement strategy requires a little | |
532 | * carefulness: to avoid multiple decrements, we flag a group, | |
533 | * more precisely an entity representing a group, as still | |
534 | * counted in num_groups_with_pending_reqs when it becomes | |
535 | * inactive. Then, when the first descendant queue of the | |
536 | * entity remains with no request waiting for completion, | |
537 | * num_groups_with_pending_reqs is decremented, and this flag | |
538 | * is reset. After this flag is reset for the entity, | |
539 | * num_groups_with_pending_reqs won't be decremented any | |
540 | * longer in case a new descendant queue of the entity remains | |
541 | * with no request waiting for completion. | |
ea25da48 | 542 | */ |
ba7aeae5 | 543 | unsigned int num_groups_with_pending_reqs; |
ea25da48 PV |
544 | |
545 | /* | |
73d58118 PV |
546 | * Per-class (RT, BE, IDLE) number of bfq_queues containing |
547 | * requests (including the queue in service, even if it is | |
548 | * idling). | |
ea25da48 | 549 | */ |
73d58118 | 550 | unsigned int busy_queues[3]; |
ea25da48 PV |
551 | /* number of weight-raised busy @bfq_queues */ |
552 | int wr_busy_queues; | |
553 | /* number of queued requests */ | |
554 | int queued; | |
555 | /* number of requests dispatched and waiting for completion */ | |
556 | int rq_in_driver; | |
557 | ||
8cacc5ab PV |
558 | /* true if the device is non rotational and performs queueing */ |
559 | bool nonrot_with_queueing; | |
560 | ||
ea25da48 PV |
561 | /* |
562 | * Maximum number of requests in driver in the last | |
563 | * @hw_tag_samples completed requests. | |
564 | */ | |
565 | int max_rq_in_driver; | |
566 | /* number of samples used to calculate hw_tag */ | |
567 | int hw_tag_samples; | |
568 | /* flag set to one if the driver is showing a queueing behavior */ | |
569 | int hw_tag; | |
570 | ||
571 | /* number of budgets assigned */ | |
572 | int budgets_assigned; | |
573 | ||
574 | /* | |
575 | * Timer set when idling (waiting) for the next request from | |
576 | * the queue in service. | |
577 | */ | |
578 | struct hrtimer idle_slice_timer; | |
579 | ||
580 | /* bfq_queue in service */ | |
581 | struct bfq_queue *in_service_queue; | |
582 | ||
583 | /* on-disk position of the last served request */ | |
584 | sector_t last_position; | |
585 | ||
058fdecc PV |
586 | /* position of the last served request for the in-service queue */ |
587 | sector_t in_serv_last_pos; | |
588 | ||
ea25da48 PV |
589 | /* time of last request completion (ns) */ |
590 | u64 last_completion; | |
591 | ||
13a857a4 PV |
592 | /* bfqq owning the last completed rq */ |
593 | struct bfq_queue *last_completed_rq_bfqq; | |
594 | ||
430a67f9 PV |
595 | /* last bfqq created, among those in the root group */ |
596 | struct bfq_queue *last_bfqq_created; | |
597 | ||
2341d662 PV |
598 | /* time of last transition from empty to non-empty (ns) */ |
599 | u64 last_empty_occupied_ns; | |
600 | ||
601 | /* | |
602 | * Flag set to activate the sampling of the total service time | |
603 | * of a just-arrived first I/O request (see | |
604 | * bfq_update_inject_limit()). This will cause the setting of | |
605 | * waited_rq when the request is finally dispatched. | |
606 | */ | |
607 | bool wait_dispatch; | |
608 | /* | |
609 | * If set, then bfq_update_inject_limit() is invoked when | |
610 | * waited_rq is eventually completed. | |
611 | */ | |
612 | struct request *waited_rq; | |
613 | /* | |
614 | * True if some request has been injected during the last service hole. | |
615 | */ | |
616 | bool rqs_injected; | |
617 | ||
ea25da48 PV |
618 | /* time of first rq dispatch in current observation interval (ns) */ |
619 | u64 first_dispatch; | |
620 | /* time of last rq dispatch in current observation interval (ns) */ | |
621 | u64 last_dispatch; | |
622 | ||
623 | /* beginning of the last budget */ | |
624 | ktime_t last_budget_start; | |
625 | /* beginning of the last idle slice */ | |
626 | ktime_t last_idling_start; | |
2341d662 | 627 | unsigned long last_idling_start_jiffies; |
ea25da48 PV |
628 | |
629 | /* number of samples in current observation interval */ | |
630 | int peak_rate_samples; | |
631 | /* num of samples of seq dispatches in current observation interval */ | |
632 | u32 sequential_samples; | |
633 | /* total num of sectors transferred in current observation interval */ | |
634 | u64 tot_sectors_dispatched; | |
635 | /* max rq size seen during current observation interval (sectors) */ | |
636 | u32 last_rq_max_size; | |
637 | /* time elapsed from first dispatch in current observ. interval (us) */ | |
638 | u64 delta_from_first; | |
639 | /* | |
640 | * Current estimate of the device peak rate, measured in | |
bc56e2ca | 641 | * [(sectors/usec) / 2^BFQ_RATE_SHIFT]. The left-shift by |
ea25da48 PV |
642 | * BFQ_RATE_SHIFT is performed to increase precision in |
643 | * fixed-point calculations. | |
644 | */ | |
645 | u32 peak_rate; | |
646 | ||
647 | /* maximum budget allotted to a bfq_queue before rescheduling */ | |
648 | int bfq_max_budget; | |
649 | ||
650 | /* list of all the bfq_queues active on the device */ | |
651 | struct list_head active_list; | |
652 | /* list of all the bfq_queues idle on the device */ | |
653 | struct list_head idle_list; | |
654 | ||
655 | /* | |
656 | * Timeout for async/sync requests; when it fires, requests | |
657 | * are served in fifo order. | |
658 | */ | |
659 | u64 bfq_fifo_expire[2]; | |
660 | /* weight of backward seeks wrt forward ones */ | |
661 | unsigned int bfq_back_penalty; | |
662 | /* maximum allowed backward seek */ | |
663 | unsigned int bfq_back_max; | |
664 | /* maximum idling time */ | |
665 | u32 bfq_slice_idle; | |
666 | ||
667 | /* user-configured max budget value (0 for auto-tuning) */ | |
668 | int bfq_user_max_budget; | |
669 | /* | |
670 | * Timeout for bfq_queues to consume their budget; used to | |
671 | * prevent seeky queues from imposing long latencies to | |
672 | * sequential or quasi-sequential ones (this also implies that | |
673 | * seeky queues cannot receive guarantees in the service | |
674 | * domain; after a timeout they are charged for the time they | |
675 | * have been in service, to preserve fairness among them, but | |
676 | * without service-domain guarantees). | |
677 | */ | |
678 | unsigned int bfq_timeout; | |
679 | ||
ea25da48 PV |
680 | /* |
681 | * Force device idling whenever needed to provide accurate | |
682 | * service guarantees, without caring about throughput | |
683 | * issues. CAVEAT: this may even increase latencies, in case | |
684 | * of useless idling for processes that did stop doing I/O. | |
685 | */ | |
686 | bool strict_guarantees; | |
687 | ||
688 | /* | |
689 | * Last time at which a queue entered the current burst of | |
690 | * queues being activated shortly after each other; for more | |
691 | * details about this and the following parameters related to | |
692 | * a burst of activations, see the comments on the function | |
693 | * bfq_handle_burst. | |
694 | */ | |
695 | unsigned long last_ins_in_burst; | |
696 | /* | |
697 | * Reference time interval used to decide whether a queue has | |
698 | * been activated shortly after @last_ins_in_burst. | |
699 | */ | |
700 | unsigned long bfq_burst_interval; | |
701 | /* number of queues in the current burst of queue activations */ | |
702 | int burst_size; | |
703 | ||
704 | /* common parent entity for the queues in the burst */ | |
705 | struct bfq_entity *burst_parent_entity; | |
706 | /* Maximum burst size above which the current queue-activation | |
707 | * burst is deemed as 'large'. | |
708 | */ | |
709 | unsigned long bfq_large_burst_thresh; | |
710 | /* true if a large queue-activation burst is in progress */ | |
711 | bool large_burst; | |
712 | /* | |
713 | * Head of the burst list (as for the above fields, more | |
714 | * details in the comments on the function bfq_handle_burst). | |
715 | */ | |
716 | struct hlist_head burst_list; | |
717 | ||
718 | /* if set to true, low-latency heuristics are enabled */ | |
719 | bool low_latency; | |
720 | /* | |
721 | * Maximum factor by which the weight of a weight-raised queue | |
722 | * is multiplied. | |
723 | */ | |
724 | unsigned int bfq_wr_coeff; | |
725 | /* maximum duration of a weight-raising period (jiffies) */ | |
726 | unsigned int bfq_wr_max_time; | |
727 | ||
728 | /* Maximum weight-raising duration for soft real-time processes */ | |
729 | unsigned int bfq_wr_rt_max_time; | |
730 | /* | |
731 | * Minimum idle period after which weight-raising may be | |
732 | * reactivated for a queue (in jiffies). | |
733 | */ | |
734 | unsigned int bfq_wr_min_idle_time; | |
735 | /* | |
736 | * Minimum period between request arrivals after which | |
737 | * weight-raising may be reactivated for an already busy async | |
738 | * queue (in jiffies). | |
739 | */ | |
740 | unsigned long bfq_wr_min_inter_arr_async; | |
741 | ||
742 | /* Max service-rate for a soft real-time queue, in sectors/sec */ | |
743 | unsigned int bfq_wr_max_softrt_rate; | |
744 | /* | |
e24f1c24 PV |
745 | * Cached value of the product ref_rate*ref_wr_duration, used |
746 | * for computing the maximum duration of weight raising | |
747 | * automatically. | |
ea25da48 | 748 | */ |
e24f1c24 | 749 | u64 rate_dur_prod; |
ea25da48 PV |
750 | |
751 | /* fallback dummy bfqq for extreme OOM conditions */ | |
752 | struct bfq_queue oom_bfqq; | |
753 | ||
754 | spinlock_t lock; | |
755 | ||
756 | /* | |
757 | * bic associated with the task issuing current bio for | |
758 | * merging. This and the next field are used as a support to | |
759 | * be able to perform the bic lookup, needed by bio-merge | |
760 | * functions, before the scheduler lock is taken, and thus | |
761 | * avoid taking the request-queue lock while the scheduler | |
762 | * lock is being held. | |
763 | */ | |
764 | struct bfq_io_cq *bio_bic; | |
765 | /* bfqq associated with the task issuing current bio for merging */ | |
766 | struct bfq_queue *bio_bfqq; | |
a52a69ea | 767 | |
a52a69ea PV |
768 | /* |
769 | * Depth limits used in bfq_limit_depth (see comments on the | |
770 | * function) | |
771 | */ | |
772 | unsigned int word_depths[2][2]; | |
44dfa279 | 773 | unsigned int full_depth_shift; |
ea25da48 PV |
774 | }; |
775 | ||
776 | enum bfqq_state_flags { | |
777 | BFQQF_just_created = 0, /* queue just allocated */ | |
778 | BFQQF_busy, /* has requests or is in service */ | |
779 | BFQQF_wait_request, /* waiting for a request */ | |
780 | BFQQF_non_blocking_wait_rq, /* | |
781 | * waiting for a request | |
782 | * without idling the device | |
783 | */ | |
784 | BFQQF_fifo_expire, /* FIFO checked in this slice */ | |
d5be3fef | 785 | BFQQF_has_short_ttime, /* queue has a short think time */ |
ea25da48 PV |
786 | BFQQF_sync, /* synchronous queue */ |
787 | BFQQF_IO_bound, /* | |
788 | * bfqq has timed-out at least once | |
789 | * having consumed at most 2/10 of | |
790 | * its budget | |
791 | */ | |
792 | BFQQF_in_large_burst, /* | |
793 | * bfqq activated in a large burst, | |
794 | * see comments to bfq_handle_burst. | |
795 | */ | |
796 | BFQQF_softrt_update, /* | |
797 | * may need softrt-next-start | |
798 | * update | |
799 | */ | |
800 | BFQQF_coop, /* bfqq is shared */ | |
13a857a4 | 801 | BFQQF_split_coop, /* shared bfqq will be split */ |
ea25da48 PV |
802 | }; |
803 | ||
804 | #define BFQ_BFQQ_FNS(name) \ | |
805 | void bfq_mark_bfqq_##name(struct bfq_queue *bfqq); \ | |
806 | void bfq_clear_bfqq_##name(struct bfq_queue *bfqq); \ | |
807 | int bfq_bfqq_##name(const struct bfq_queue *bfqq); | |
808 | ||
809 | BFQ_BFQQ_FNS(just_created); | |
810 | BFQ_BFQQ_FNS(busy); | |
811 | BFQ_BFQQ_FNS(wait_request); | |
812 | BFQ_BFQQ_FNS(non_blocking_wait_rq); | |
813 | BFQ_BFQQ_FNS(fifo_expire); | |
d5be3fef | 814 | BFQ_BFQQ_FNS(has_short_ttime); |
ea25da48 PV |
815 | BFQ_BFQQ_FNS(sync); |
816 | BFQ_BFQQ_FNS(IO_bound); | |
817 | BFQ_BFQQ_FNS(in_large_burst); | |
818 | BFQ_BFQQ_FNS(coop); | |
819 | BFQ_BFQQ_FNS(split_coop); | |
820 | BFQ_BFQQ_FNS(softrt_update); | |
821 | #undef BFQ_BFQQ_FNS | |
822 | ||
823 | /* Expiration reasons. */ | |
824 | enum bfqq_expiration { | |
825 | BFQQE_TOO_IDLE = 0, /* | |
826 | * queue has been idling for | |
827 | * too long | |
828 | */ | |
829 | BFQQE_BUDGET_TIMEOUT, /* budget took too long to be used */ | |
830 | BFQQE_BUDGET_EXHAUSTED, /* budget consumed */ | |
831 | BFQQE_NO_MORE_REQUESTS, /* the queue has no more requests */ | |
832 | BFQQE_PREEMPTED /* preemption in progress */ | |
833 | }; | |
834 | ||
c0ce79dc CH |
835 | struct bfq_stat { |
836 | struct percpu_counter cpu_cnt; | |
837 | atomic64_t aux_cnt; | |
838 | }; | |
839 | ||
ea25da48 | 840 | struct bfqg_stats { |
fd41e603 TH |
841 | /* basic stats */ |
842 | struct blkg_rwstat bytes; | |
843 | struct blkg_rwstat ios; | |
8060c47b | 844 | #ifdef CONFIG_BFQ_CGROUP_DEBUG |
ea25da48 PV |
845 | /* number of ios merged */ |
846 | struct blkg_rwstat merged; | |
847 | /* total time spent on device in ns, may not be accurate w/ queueing */ | |
848 | struct blkg_rwstat service_time; | |
849 | /* total time spent waiting in scheduler queue in ns */ | |
850 | struct blkg_rwstat wait_time; | |
851 | /* number of IOs queued up */ | |
852 | struct blkg_rwstat queued; | |
853 | /* total disk time and nr sectors dispatched by this group */ | |
c0ce79dc | 854 | struct bfq_stat time; |
ea25da48 | 855 | /* sum of number of ios queued across all samples */ |
c0ce79dc | 856 | struct bfq_stat avg_queue_size_sum; |
ea25da48 | 857 | /* count of samples taken for average */ |
c0ce79dc | 858 | struct bfq_stat avg_queue_size_samples; |
ea25da48 | 859 | /* how many times this group has been removed from service tree */ |
c0ce79dc | 860 | struct bfq_stat dequeue; |
ea25da48 | 861 | /* total time spent waiting for it to be assigned a timeslice. */ |
c0ce79dc | 862 | struct bfq_stat group_wait_time; |
ea25da48 | 863 | /* time spent idling for this blkcg_gq */ |
c0ce79dc | 864 | struct bfq_stat idle_time; |
ea25da48 | 865 | /* total time with empty current active q with other requests queued */ |
c0ce79dc | 866 | struct bfq_stat empty_time; |
ea25da48 | 867 | /* fields after this shouldn't be cleared on stat reset */ |
84c7afce OS |
868 | u64 start_group_wait_time; |
869 | u64 start_idle_time; | |
870 | u64 start_empty_time; | |
ea25da48 | 871 | uint16_t flags; |
8060c47b | 872 | #endif /* CONFIG_BFQ_CGROUP_DEBUG */ |
ea25da48 PV |
873 | }; |
874 | ||
875 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
876 | ||
877 | /* | |
878 | * struct bfq_group_data - per-blkcg storage for the blkio subsystem. | |
879 | * | |
880 | * @ps: @blkcg_policy_storage that this structure inherits | |
881 | * @weight: weight of the bfq_group | |
882 | */ | |
883 | struct bfq_group_data { | |
884 | /* must be the first member */ | |
885 | struct blkcg_policy_data pd; | |
886 | ||
887 | unsigned int weight; | |
888 | }; | |
889 | ||
890 | /** | |
891 | * struct bfq_group - per (device, cgroup) data structure. | |
892 | * @entity: schedulable entity to insert into the parent group sched_data. | |
893 | * @sched_data: own sched_data, to contain child entities (they may be | |
894 | * both bfq_queues and bfq_groups). | |
895 | * @bfqd: the bfq_data for the device this group acts upon. | |
896 | * @async_bfqq: array of async queues for all the tasks belonging to | |
897 | * the group, one queue per ioprio value per ioprio_class, | |
898 | * except for the idle class that has only one queue. | |
899 | * @async_idle_bfqq: async queue for the idle class (ioprio is ignored). | |
900 | * @my_entity: pointer to @entity, %NULL for the toplevel group; used | |
901 | * to avoid too many special cases during group creation/ | |
902 | * migration. | |
903 | * @stats: stats for this bfqg. | |
904 | * @active_entities: number of active entities belonging to the group; | |
905 | * unused for the root group. Used to know whether there | |
906 | * are groups with more than one active @bfq_entity | |
907 | * (see the comments to the function | |
908 | * bfq_bfqq_may_idle()). | |
909 | * @rq_pos_tree: rbtree sorted by next_request position, used when | |
910 | * determining if two or more queues have interleaving | |
911 | * requests (see bfq_find_close_cooperator()). | |
912 | * | |
913 | * Each (device, cgroup) pair has its own bfq_group, i.e., for each cgroup | |
914 | * there is a set of bfq_groups, each one collecting the lower-level | |
915 | * entities belonging to the group that are acting on the same device. | |
916 | * | |
917 | * Locking works as follows: | |
918 | * o @bfqd is protected by the queue lock, RCU is used to access it | |
919 | * from the readers. | |
920 | * o All the other fields are protected by the @bfqd queue lock. | |
921 | */ | |
922 | struct bfq_group { | |
923 | /* must be the first member */ | |
924 | struct blkg_policy_data pd; | |
925 | ||
8f9bebc3 PV |
926 | /* cached path for this blkg (see comments in bfq_bic_update_cgroup) */ |
927 | char blkg_path[128]; | |
928 | ||
929 | /* reference counter (see comments in bfq_bic_update_cgroup) */ | |
930 | int ref; | |
931 | ||
ea25da48 PV |
932 | struct bfq_entity entity; |
933 | struct bfq_sched_data sched_data; | |
934 | ||
935 | void *bfqd; | |
936 | ||
202bc942 | 937 | struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS]; |
ea25da48 PV |
938 | struct bfq_queue *async_idle_bfqq; |
939 | ||
940 | struct bfq_entity *my_entity; | |
941 | ||
942 | int active_entities; | |
943 | ||
944 | struct rb_root rq_pos_tree; | |
945 | ||
946 | struct bfqg_stats stats; | |
947 | }; | |
948 | ||
949 | #else | |
950 | struct bfq_group { | |
4d8340d0 | 951 | struct bfq_entity entity; |
ea25da48 PV |
952 | struct bfq_sched_data sched_data; |
953 | ||
202bc942 | 954 | struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS]; |
ea25da48 PV |
955 | struct bfq_queue *async_idle_bfqq; |
956 | ||
957 | struct rb_root rq_pos_tree; | |
958 | }; | |
959 | #endif | |
960 | ||
ea25da48 PV |
961 | /* --------------- main algorithm interface ----------------- */ |
962 | ||
963 | #define BFQ_SERVICE_TREE_INIT ((struct bfq_service_tree) \ | |
964 | { RB_ROOT, RB_ROOT, NULL, NULL, 0, 0 }) | |
965 | ||
966 | extern const int bfq_timeout; | |
967 | ||
968 | struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync); | |
969 | void bic_set_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq, bool is_sync); | |
970 | struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic); | |
ea25da48 | 971 | void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq); |
2d29c9f8 | 972 | void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
fb53ac6c | 973 | struct rb_root_cached *root); |
0471559c | 974 | void __bfq_weights_tree_remove(struct bfq_data *bfqd, |
2d29c9f8 | 975 | struct bfq_queue *bfqq, |
fb53ac6c | 976 | struct rb_root_cached *root); |
0471559c PV |
977 | void bfq_weights_tree_remove(struct bfq_data *bfqd, |
978 | struct bfq_queue *bfqq); | |
ea25da48 PV |
979 | void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
980 | bool compensate, enum bfqq_expiration reason); | |
981 | void bfq_put_queue(struct bfq_queue *bfqq); | |
982 | void bfq_end_wr_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); | |
c8997736 | 983 | void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq); |
ea25da48 PV |
984 | void bfq_schedule_dispatch(struct bfq_data *bfqd); |
985 | void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); | |
986 | ||
987 | /* ------------ end of main algorithm interface -------------- */ | |
988 | ||
989 | /* ---------------- cgroups-support interface ---------------- */ | |
990 | ||
fd41e603 | 991 | void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq); |
ea25da48 PV |
992 | void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq, |
993 | unsigned int op); | |
994 | void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op); | |
995 | void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op); | |
84c7afce OS |
996 | void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns, |
997 | u64 io_start_time_ns, unsigned int op); | |
ea25da48 PV |
998 | void bfqg_stats_update_dequeue(struct bfq_group *bfqg); |
999 | void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg); | |
1000 | void bfqg_stats_update_idle_time(struct bfq_group *bfqg); | |
1001 | void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg); | |
1002 | void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg); | |
1003 | void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, | |
1004 | struct bfq_group *bfqg); | |
1005 | ||
1006 | void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg); | |
1007 | void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio); | |
1008 | void bfq_end_wr_async(struct bfq_data *bfqd); | |
1009 | struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, | |
1010 | struct blkcg *blkcg); | |
1011 | struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg); | |
1012 | struct bfq_group *bfqq_group(struct bfq_queue *bfqq); | |
1013 | struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node); | |
8f9bebc3 | 1014 | void bfqg_and_blkg_put(struct bfq_group *bfqg); |
ea25da48 PV |
1015 | |
1016 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
659b3394 JA |
1017 | extern struct cftype bfq_blkcg_legacy_files[]; |
1018 | extern struct cftype bfq_blkg_files[]; | |
ea25da48 PV |
1019 | extern struct blkcg_policy blkcg_policy_bfq; |
1020 | #endif | |
1021 | ||
1022 | /* ------------- end of cgroups-support interface ------------- */ | |
1023 | ||
1024 | /* - interface of the internal hierarchical B-WF2Q+ scheduler - */ | |
1025 | ||
1026 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
1027 | /* both next loops stop at one of the child entities of the root group */ | |
1028 | #define for_each_entity(entity) \ | |
1029 | for (; entity ; entity = entity->parent) | |
1030 | ||
1031 | /* | |
1032 | * For each iteration, compute parent in advance, so as to be safe if | |
1033 | * entity is deallocated during the iteration. Such a deallocation may | |
1034 | * happen as a consequence of a bfq_put_queue that frees the bfq_queue | |
1035 | * containing entity. | |
1036 | */ | |
1037 | #define for_each_entity_safe(entity, parent) \ | |
1038 | for (; entity && ({ parent = entity->parent; 1; }); entity = parent) | |
1039 | ||
1040 | #else /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1041 | /* | |
1042 | * Next two macros are fake loops when cgroups support is not | |
1043 | * enabled. I fact, in such a case, there is only one level to go up | |
1044 | * (to reach the root group). | |
1045 | */ | |
1046 | #define for_each_entity(entity) \ | |
1047 | for (; entity ; entity = NULL) | |
1048 | ||
1049 | #define for_each_entity_safe(entity, parent) \ | |
1050 | for (parent = NULL; entity ; entity = parent) | |
1051 | #endif /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1052 | ||
ea25da48 | 1053 | struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity); |
73d58118 | 1054 | unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd); |
ea25da48 PV |
1055 | struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity); |
1056 | struct bfq_entity *bfq_entity_of(struct rb_node *node); | |
1057 | unsigned short bfq_ioprio_to_weight(int ioprio); | |
1058 | void bfq_put_idle_entity(struct bfq_service_tree *st, | |
1059 | struct bfq_entity *entity); | |
1060 | struct bfq_service_tree * | |
1061 | __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st, | |
431b17f9 PV |
1062 | struct bfq_entity *entity, |
1063 | bool update_class_too); | |
ea25da48 PV |
1064 | void bfq_bfqq_served(struct bfq_queue *bfqq, int served); |
1065 | void bfq_bfqq_charge_time(struct bfq_data *bfqd, struct bfq_queue *bfqq, | |
1066 | unsigned long time_ms); | |
1067 | bool __bfq_deactivate_entity(struct bfq_entity *entity, | |
1068 | bool ins_into_idle_tree); | |
1069 | bool next_queue_may_preempt(struct bfq_data *bfqd); | |
1070 | struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd); | |
eed47d19 | 1071 | bool __bfq_bfqd_reset_in_service(struct bfq_data *bfqd); |
ea25da48 PV |
1072 | void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1073 | bool ins_into_idle_tree, bool expiration); | |
1074 | void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq); | |
80294c3b PV |
1075 | void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1076 | bool expiration); | |
ea25da48 PV |
1077 | void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1078 | bool expiration); | |
1079 | void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq); | |
1080 | ||
1081 | /* --------------- end of interface of B-WF2Q+ ---------------- */ | |
1082 | ||
1083 | /* Logging facilities. */ | |
582f04e1 | 1084 | static inline void bfq_bfqq_name(struct bfq_queue *bfqq, char *str, int len) |
1e66413c | 1085 | { |
582f04e1 JK |
1086 | char type = bfq_bfqq_sync(bfqq) ? 'S' : 'A'; |
1087 | ||
1088 | if (bfqq->pid != -1) | |
1089 | snprintf(str, len, "bfq%d%c", bfqq->pid, type); | |
1e66413c | 1090 | else |
582f04e1 | 1091 | snprintf(str, len, "bfqSHARED-%c", type); |
1e66413c FP |
1092 | } |
1093 | ||
ea25da48 PV |
1094 | #ifdef CONFIG_BFQ_GROUP_IOSCHED |
1095 | struct bfq_group *bfqq_group(struct bfq_queue *bfqq); | |
1096 | ||
1097 | #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ | |
582f04e1 | 1098 | char pid_str[MAX_BFQQ_NAME_LENGTH]; \ |
40d47c15 DM |
1099 | if (likely(!blk_trace_note_message_enabled((bfqd)->queue))) \ |
1100 | break; \ | |
582f04e1 | 1101 | bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH); \ |
35fe6d76 SL |
1102 | blk_add_cgroup_trace_msg((bfqd)->queue, \ |
1103 | bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \ | |
582f04e1 | 1104 | "%s " fmt, pid_str, ##args); \ |
ea25da48 PV |
1105 | } while (0) |
1106 | ||
35fe6d76 SL |
1107 | #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do { \ |
1108 | blk_add_cgroup_trace_msg((bfqd)->queue, \ | |
1109 | bfqg_to_blkg(bfqg)->blkcg, fmt, ##args); \ | |
1110 | } while (0) | |
ea25da48 PV |
1111 | |
1112 | #else /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1113 | ||
1e66413c | 1114 | #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ |
582f04e1 | 1115 | char pid_str[MAX_BFQQ_NAME_LENGTH]; \ |
40d47c15 DM |
1116 | if (likely(!blk_trace_note_message_enabled((bfqd)->queue))) \ |
1117 | break; \ | |
582f04e1 JK |
1118 | bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH); \ |
1119 | blk_add_trace_msg((bfqd)->queue, "%s " fmt, pid_str, ##args); \ | |
1e66413c | 1120 | } while (0) |
ea25da48 PV |
1121 | #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do {} while (0) |
1122 | ||
1123 | #endif /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1124 | ||
1125 | #define bfq_log(bfqd, fmt, args...) \ | |
1126 | blk_add_trace_msg((bfqd)->queue, "bfq " fmt, ##args) | |
1127 | ||
1128 | #endif /* _BFQ_H */ |