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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 | ||
ea25da48 PV |
23 | #define BFQ_DEFAULT_GRP_IOPRIO 0 |
24 | #define BFQ_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE | |
25 | ||
582f04e1 | 26 | #define MAX_BFQQ_NAME_LENGTH 16 |
1e66413c | 27 | |
ea25da48 PV |
28 | /* |
29 | * Soft real-time applications are extremely more latency sensitive | |
30 | * than interactive ones. Over-raise the weight of the former to | |
31 | * privilege them against the latter. | |
32 | */ | |
33 | #define BFQ_SOFTRT_WEIGHT_FACTOR 100 | |
34 | ||
9778369a PV |
35 | /* |
36 | * Maximum number of actuators supported. This constant is used simply | |
37 | * to define the size of the static array that will contain | |
38 | * per-actuator data. The current value is hopefully a good upper | |
39 | * bound to the possible number of actuators of any actual drive. | |
40 | */ | |
41 | #define BFQ_MAX_ACTUATORS 8 | |
42 | ||
ea25da48 PV |
43 | struct bfq_entity; |
44 | ||
45 | /** | |
46 | * struct bfq_service_tree - per ioprio_class service tree. | |
47 | * | |
48 | * Each service tree represents a B-WF2Q+ scheduler on its own. Each | |
49 | * ioprio_class has its own independent scheduler, and so its own | |
50 | * bfq_service_tree. All the fields are protected by the queue lock | |
51 | * of the containing bfqd. | |
52 | */ | |
53 | struct bfq_service_tree { | |
54 | /* tree for active entities (i.e., those backlogged) */ | |
55 | struct rb_root active; | |
38c91407 | 56 | /* tree for idle entities (i.e., not backlogged, with V < F_i)*/ |
ea25da48 PV |
57 | struct rb_root idle; |
58 | ||
59 | /* idle entity with minimum F_i */ | |
60 | struct bfq_entity *first_idle; | |
61 | /* idle entity with maximum F_i */ | |
62 | struct bfq_entity *last_idle; | |
63 | ||
64 | /* scheduler virtual time */ | |
65 | u64 vtime; | |
66 | /* scheduler weight sum; active and idle entities contribute to it */ | |
67 | unsigned long wsum; | |
68 | }; | |
69 | ||
70 | /** | |
71 | * struct bfq_sched_data - multi-class scheduler. | |
72 | * | |
73 | * bfq_sched_data is the basic scheduler queue. It supports three | |
74 | * ioprio_classes, and can be used either as a toplevel queue or as an | |
46d556e6 | 75 | * intermediate queue in a hierarchical setup. |
ea25da48 PV |
76 | * |
77 | * The supported ioprio_classes are the same as in CFQ, in descending | |
78 | * priority order, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE. | |
79 | * Requests from higher priority queues are served before all the | |
80 | * requests from lower priority queues; among requests of the same | |
81 | * queue requests are served according to B-WF2Q+. | |
46d556e6 PV |
82 | * |
83 | * The schedule is implemented by the service trees, plus the field | |
84 | * @next_in_service, which points to the entity on the active trees | |
85 | * that will be served next, if 1) no changes in the schedule occurs | |
86 | * before the current in-service entity is expired, 2) the in-service | |
87 | * queue becomes idle when it expires, and 3) if the entity pointed by | |
88 | * in_service_entity is not a queue, then the in-service child entity | |
89 | * of the entity pointed by in_service_entity becomes idle on | |
90 | * expiration. This peculiar definition allows for the following | |
91 | * optimization, not yet exploited: while a given entity is still in | |
92 | * service, we already know which is the best candidate for next | |
636b8fe8 | 93 | * service among the other active entities in the same parent |
46d556e6 PV |
94 | * entity. We can then quickly compare the timestamps of the |
95 | * in-service entity with those of such best candidate. | |
96 | * | |
97 | * All fields are protected by the lock of the containing bfqd. | |
ea25da48 PV |
98 | */ |
99 | struct bfq_sched_data { | |
100 | /* entity in service */ | |
101 | struct bfq_entity *in_service_entity; | |
102 | /* head-of-line entity (see comments above) */ | |
103 | struct bfq_entity *next_in_service; | |
104 | /* array of service trees, one per ioprio_class */ | |
105 | struct bfq_service_tree service_tree[BFQ_IOPRIO_CLASSES]; | |
106 | /* last time CLASS_IDLE was served */ | |
107 | unsigned long bfq_class_idle_last_service; | |
108 | ||
109 | }; | |
110 | ||
111 | /** | |
2d29c9f8 | 112 | * struct bfq_weight_counter - counter of the number of all active queues |
ea25da48 PV |
113 | * with a given weight. |
114 | */ | |
115 | struct bfq_weight_counter { | |
2d29c9f8 FM |
116 | unsigned int weight; /* weight of the queues this counter refers to */ |
117 | unsigned int num_active; /* nr of active queues with this weight */ | |
ea25da48 | 118 | /* |
2d29c9f8 | 119 | * Weights tree member (see bfq_data's @queue_weights_tree) |
ea25da48 PV |
120 | */ |
121 | struct rb_node weights_node; | |
122 | }; | |
123 | ||
124 | /** | |
125 | * struct bfq_entity - schedulable entity. | |
126 | * | |
127 | * A bfq_entity is used to represent either a bfq_queue (leaf node in the | |
128 | * cgroup hierarchy) or a bfq_group into the upper level scheduler. Each | |
129 | * entity belongs to the sched_data of the parent group in the cgroup | |
130 | * hierarchy. Non-leaf entities have also their own sched_data, stored | |
131 | * in @my_sched_data. | |
132 | * | |
133 | * Each entity stores independently its priority values; this would | |
134 | * allow different weights on different devices, but this | |
135 | * functionality is not exported to userspace by now. Priorities and | |
136 | * weights are updated lazily, first storing the new values into the | |
137 | * new_* fields, then setting the @prio_changed flag. As soon as | |
138 | * there is a transition in the entity state that allows the priority | |
139 | * update to take place the effective and the requested priority | |
140 | * values are synchronized. | |
141 | * | |
142 | * Unless cgroups are used, the weight value is calculated from the | |
143 | * ioprio to export the same interface as CFQ. When dealing with | |
636b8fe8 | 144 | * "well-behaved" queues (i.e., queues that do not spend too much |
ea25da48 PV |
145 | * time to consume their budget and have true sequential behavior, and |
146 | * when there are no external factors breaking anticipation) the | |
147 | * relative weights at each level of the cgroups hierarchy should be | |
148 | * guaranteed. All the fields are protected by the queue lock of the | |
149 | * containing bfqd. | |
150 | */ | |
151 | struct bfq_entity { | |
152 | /* service_tree member */ | |
153 | struct rb_node rb_node; | |
ea25da48 PV |
154 | |
155 | /* | |
156 | * Flag, true if the entity is on a tree (either the active or | |
157 | * the idle one of its service_tree) or is in service. | |
158 | */ | |
33a16a98 | 159 | bool on_st_or_in_serv; |
ea25da48 PV |
160 | |
161 | /* B-WF2Q+ start and finish timestamps [sectors/weight] */ | |
162 | u64 start, finish; | |
163 | ||
164 | /* tree the entity is enqueued into; %NULL if not on a tree */ | |
165 | struct rb_root *tree; | |
166 | ||
167 | /* | |
168 | * minimum start time of the (active) subtree rooted at this | |
169 | * entity; used for O(log N) lookups into active trees | |
170 | */ | |
171 | u64 min_start; | |
172 | ||
173 | /* amount of service received during the last service slot */ | |
174 | int service; | |
175 | ||
176 | /* budget, used also to calculate F_i: F_i = S_i + @budget / @weight */ | |
177 | int budget; | |
178 | ||
98f04499 JK |
179 | /* Number of requests allocated in the subtree of this entity */ |
180 | int allocated; | |
181 | ||
795fe54c FZ |
182 | /* device weight, if non-zero, it overrides the default weight of |
183 | * bfq_group_data */ | |
184 | int dev_weight; | |
ea25da48 PV |
185 | /* weight of the queue */ |
186 | int weight; | |
187 | /* next weight if a change is in progress */ | |
188 | int new_weight; | |
189 | ||
190 | /* original weight, used to implement weight boosting */ | |
191 | int orig_weight; | |
192 | ||
193 | /* parent entity, for hierarchical scheduling */ | |
194 | struct bfq_entity *parent; | |
195 | ||
196 | /* | |
197 | * For non-leaf nodes in the hierarchy, the associated | |
198 | * scheduler queue, %NULL on leaf nodes. | |
199 | */ | |
200 | struct bfq_sched_data *my_sched_data; | |
201 | /* the scheduler queue this entity belongs to */ | |
202 | struct bfq_sched_data *sched_data; | |
203 | ||
204 | /* flag, set to request a weight, ioprio or ioprio_class change */ | |
205 | int prio_changed; | |
ba7aeae5 | 206 | |
1eb20620 | 207 | #ifdef CONFIG_BFQ_GROUP_IOSCHED |
ba7aeae5 PV |
208 | /* flag, set if the entity is counted in groups_with_pending_reqs */ |
209 | bool in_groups_with_pending_reqs; | |
1eb20620 | 210 | #endif |
430a67f9 PV |
211 | |
212 | /* last child queue of entity created (for non-leaf entities) */ | |
213 | struct bfq_queue *last_bfqq_created; | |
ea25da48 PV |
214 | }; |
215 | ||
216 | struct bfq_group; | |
217 | ||
218 | /** | |
219 | * struct bfq_ttime - per process thinktime stats. | |
220 | */ | |
221 | struct bfq_ttime { | |
222 | /* completion time of the last request */ | |
223 | u64 last_end_request; | |
224 | ||
225 | /* total process thinktime */ | |
226 | u64 ttime_total; | |
227 | /* number of thinktime samples */ | |
228 | unsigned long ttime_samples; | |
229 | /* average process thinktime */ | |
230 | u64 ttime_mean; | |
231 | }; | |
232 | ||
233 | /** | |
234 | * struct bfq_queue - leaf schedulable entity. | |
235 | * | |
236 | * A bfq_queue is a leaf request queue; it can be associated with an | |
9778369a PV |
237 | * io_context or more, if it is async or shared between cooperating |
238 | * processes. Besides, it contains I/O requests for only one actuator | |
239 | * (an io_context is associated with a different bfq_queue for each | |
240 | * actuator it generates I/O for). @cgroup holds a reference to the | |
241 | * cgroup, to be sure that it does not disappear while a bfqq still | |
242 | * references it (mostly to avoid races between request issuing and | |
243 | * task migration followed by cgroup destruction). All the fields are | |
244 | * protected by the queue lock of the containing bfqd. | |
ea25da48 PV |
245 | */ |
246 | struct bfq_queue { | |
247 | /* reference counter */ | |
248 | int ref; | |
430a67f9 PV |
249 | /* counter of references from other queues for delayed stable merge */ |
250 | int stable_ref; | |
ea25da48 PV |
251 | /* parent bfq_data */ |
252 | struct bfq_data *bfqd; | |
253 | ||
254 | /* current ioprio and ioprio class */ | |
255 | unsigned short ioprio, ioprio_class; | |
256 | /* next ioprio and ioprio class if a change is in progress */ | |
257 | unsigned short new_ioprio, new_ioprio_class; | |
258 | ||
2341d662 PV |
259 | /* last total-service-time sample, see bfq_update_inject_limit() */ |
260 | u64 last_serv_time_ns; | |
261 | /* limit for request injection */ | |
262 | unsigned int inject_limit; | |
263 | /* last time the inject limit has been decreased, in jiffies */ | |
264 | unsigned long decrease_time_jif; | |
265 | ||
ea25da48 PV |
266 | /* |
267 | * Shared bfq_queue if queue is cooperating with one or more | |
268 | * other queues. | |
269 | */ | |
270 | struct bfq_queue *new_bfqq; | |
271 | /* request-position tree member (see bfq_group's @rq_pos_tree) */ | |
272 | struct rb_node pos_node; | |
273 | /* request-position tree root (see bfq_group's @rq_pos_tree) */ | |
274 | struct rb_root *pos_root; | |
275 | ||
276 | /* sorted list of pending requests */ | |
277 | struct rb_root sort_list; | |
278 | /* if fifo isn't expired, next request to serve */ | |
279 | struct request *next_rq; | |
280 | /* number of sync and async requests queued */ | |
281 | int queued[2]; | |
ea25da48 PV |
282 | /* number of pending metadata requests */ |
283 | int meta_pending; | |
284 | /* fifo list of requests in sort_list */ | |
285 | struct list_head fifo; | |
286 | ||
287 | /* entity representing this queue in the scheduler */ | |
288 | struct bfq_entity entity; | |
289 | ||
2d29c9f8 FM |
290 | /* pointer to the weight counter associated with this entity */ |
291 | struct bfq_weight_counter *weight_counter; | |
292 | ||
ea25da48 PV |
293 | /* maximum budget allowed from the feedback mechanism */ |
294 | int max_budget; | |
295 | /* budget expiration (in jiffies) */ | |
296 | unsigned long budget_timeout; | |
297 | ||
298 | /* number of requests on the dispatch list or inside driver */ | |
299 | int dispatched; | |
300 | ||
301 | /* status flags */ | |
302 | unsigned long flags; | |
303 | ||
304 | /* node for active/idle bfqq list inside parent bfqd */ | |
305 | struct list_head bfqq_list; | |
306 | ||
307 | /* associated @bfq_ttime struct */ | |
308 | struct bfq_ttime ttime; | |
309 | ||
eb2fd80f PV |
310 | /* when bfqq started to do I/O within the last observation window */ |
311 | u64 io_start_time; | |
312 | /* how long bfqq has remained empty during the last observ. window */ | |
313 | u64 tot_idle_time; | |
314 | ||
ea25da48 PV |
315 | /* bit vector: a 1 for each seeky requests in history */ |
316 | u32 seek_history; | |
317 | ||
318 | /* node for the device's burst list */ | |
319 | struct hlist_node burst_list_node; | |
320 | ||
321 | /* position of the last request enqueued */ | |
322 | sector_t last_request_pos; | |
323 | ||
324 | /* Number of consecutive pairs of request completion and | |
325 | * arrival, such that the queue becomes idle after the | |
326 | * completion, but the next request arrives within an idle | |
327 | * time slice; used only if the queue's IO_bound flag has been | |
328 | * cleared. | |
329 | */ | |
330 | unsigned int requests_within_timer; | |
331 | ||
332 | /* pid of the process owning the queue, used for logging purposes */ | |
333 | pid_t pid; | |
334 | ||
335 | /* | |
336 | * Pointer to the bfq_io_cq owning the bfq_queue, set to %NULL | |
337 | * if the queue is shared. | |
338 | */ | |
339 | struct bfq_io_cq *bic; | |
340 | ||
341 | /* current maximum weight-raising time for this queue */ | |
342 | unsigned long wr_cur_max_time; | |
343 | /* | |
344 | * Minimum time instant such that, only if a new request is | |
345 | * enqueued after this time instant in an idle @bfq_queue with | |
346 | * no outstanding requests, then the task associated with the | |
347 | * queue it is deemed as soft real-time (see the comments on | |
348 | * the function bfq_bfqq_softrt_next_start()) | |
349 | */ | |
350 | unsigned long soft_rt_next_start; | |
351 | /* | |
352 | * Start time of the current weight-raising period if | |
353 | * the @bfq-queue is being weight-raised, otherwise | |
354 | * finish time of the last weight-raising period. | |
355 | */ | |
356 | unsigned long last_wr_start_finish; | |
357 | /* factor by which the weight of this queue is multiplied */ | |
358 | unsigned int wr_coeff; | |
359 | /* | |
360 | * Time of the last transition of the @bfq_queue from idle to | |
361 | * backlogged. | |
362 | */ | |
363 | unsigned long last_idle_bklogged; | |
364 | /* | |
365 | * Cumulative service received from the @bfq_queue since the | |
366 | * last transition from idle to backlogged. | |
367 | */ | |
368 | unsigned long service_from_backlogged; | |
8a8747dc PV |
369 | /* |
370 | * Cumulative service received from the @bfq_queue since its | |
371 | * last transition to weight-raised state. | |
372 | */ | |
373 | unsigned long service_from_wr; | |
ea25da48 PV |
374 | |
375 | /* | |
376 | * Value of wr start time when switching to soft rt | |
377 | */ | |
378 | unsigned long wr_start_at_switch_to_srt; | |
379 | ||
380 | unsigned long split_time; /* time of last split */ | |
7b8fa3b9 PV |
381 | |
382 | unsigned long first_IO_time; /* time of first I/O for this queue */ | |
430a67f9 PV |
383 | unsigned long creation_time; /* when this queue is created */ |
384 | ||
13a857a4 PV |
385 | /* |
386 | * Pointer to the waker queue for this queue, i.e., to the | |
387 | * queue Q such that this queue happens to get new I/O right | |
388 | * after some I/O request of Q is completed. For details, see | |
389 | * the comments on the choice of the queue for injection in | |
390 | * bfq_select_queue(). | |
391 | */ | |
392 | struct bfq_queue *waker_bfqq; | |
71217df3 PV |
393 | /* pointer to the curr. tentative waker queue, see bfq_check_waker() */ |
394 | struct bfq_queue *tentative_waker_bfqq; | |
395 | /* number of times the same tentative waker has been detected */ | |
396 | unsigned int num_waker_detections; | |
1f18b700 JK |
397 | /* time when we started considering this waker */ |
398 | u64 waker_detection_started; | |
71217df3 | 399 | |
13a857a4 PV |
400 | /* node for woken_list, see below */ |
401 | struct hlist_node woken_list_node; | |
402 | /* | |
403 | * Head of the list of the woken queues for this queue, i.e., | |
404 | * of the list of the queues for which this queue is a waker | |
405 | * queue. This list is used to reset the waker_bfqq pointer in | |
406 | * the woken queues when this queue exits. | |
407 | */ | |
408 | struct hlist_head woken_list; | |
9778369a PV |
409 | |
410 | /* index of the actuator this queue is associated with */ | |
411 | unsigned int actuator_idx; | |
ea25da48 PV |
412 | }; |
413 | ||
414 | /** | |
a6123047 PV |
415 | * struct bfq_data - bfqq data unique and persistent for associated bfq_io_cq |
416 | */ | |
417 | struct bfq_iocq_bfqq_data { | |
ea25da48 | 418 | /* |
d5be3fef | 419 | * Snapshot of the has_short_time flag before merging; taken |
fd571df0 | 420 | * to remember its values while the queue is merged, so as to |
d5be3fef | 421 | * be able to restore it in case of split. |
ea25da48 | 422 | */ |
d5be3fef | 423 | bool saved_has_short_ttime; |
ea25da48 PV |
424 | /* |
425 | * Same purpose as the previous two fields for the I/O bound | |
426 | * classification of a queue. | |
427 | */ | |
428 | bool saved_IO_bound; | |
429 | ||
eb2fd80f PV |
430 | u64 saved_io_start_time; |
431 | u64 saved_tot_idle_time; | |
432 | ||
ea25da48 | 433 | /* |
fd571df0 | 434 | * Same purpose as the previous fields for the values of the |
ea25da48 PV |
435 | * field keeping the queue's belonging to a large burst |
436 | */ | |
437 | bool saved_in_large_burst; | |
438 | /* | |
439 | * True if the queue belonged to a burst list before its merge | |
440 | * with another cooperating queue. | |
441 | */ | |
442 | bool was_in_burst_list; | |
443 | ||
fffca087 FP |
444 | /* |
445 | * Save the weight when a merge occurs, to be able | |
446 | * to restore it in case of split. If the weight is not | |
447 | * correctly resumed when the queue is recycled, | |
448 | * then the weight of the recycled queue could differ | |
449 | * from the weight of the original queue. | |
450 | */ | |
451 | unsigned int saved_weight; | |
452 | ||
ea25da48 PV |
453 | /* |
454 | * Similar to previous fields: save wr information. | |
455 | */ | |
456 | unsigned long saved_wr_coeff; | |
457 | unsigned long saved_last_wr_start_finish; | |
e673914d | 458 | unsigned long saved_service_from_wr; |
ea25da48 PV |
459 | unsigned long saved_wr_start_at_switch_to_srt; |
460 | unsigned int saved_wr_cur_max_time; | |
461 | struct bfq_ttime saved_ttime; | |
5a5436b9 PV |
462 | |
463 | /* Save also injection state */ | |
464 | u64 saved_last_serv_time_ns; | |
465 | unsigned int saved_inject_limit; | |
466 | unsigned long saved_decrease_time_jif; | |
430a67f9 PV |
467 | |
468 | /* candidate queue for a stable merge (due to close creation time) */ | |
469 | struct bfq_queue *stable_merge_bfqq; | |
470 | ||
471 | bool stably_merged; /* non splittable if true */ | |
a6123047 PV |
472 | }; |
473 | ||
474 | /** | |
475 | * struct bfq_io_cq - per (request_queue, io_context) structure. | |
476 | */ | |
477 | struct bfq_io_cq { | |
478 | /* associated io_cq structure */ | |
479 | struct io_cq icq; /* must be the first member */ | |
480 | /* | |
481 | * Matrix of associated process queues: first row for async | |
482 | * queues, second row sync queues. Each row contains one | |
483 | * column for each actuator. An I/O request generated by the | |
484 | * process is inserted into the queue pointed by bfqq[i][j] if | |
485 | * the request is to be served by the j-th actuator of the | |
486 | * drive, where i==0 or i==1, depending on whether the request | |
487 | * is async or sync. So there is a distinct queue for each | |
488 | * actuator. | |
489 | */ | |
490 | struct bfq_queue *bfqq[2][BFQ_MAX_ACTUATORS]; | |
491 | /* per (request_queue, blkcg) ioprio */ | |
492 | int ioprio; | |
493 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
494 | uint64_t blkcg_serial_nr; /* the current blkcg serial */ | |
495 | #endif | |
496 | ||
fd571df0 PV |
497 | /* |
498 | * Persistent data for associated synchronous process queues | |
499 | * (one queue per actuator, see field bfqq above). In | |
500 | * particular, each of these queues may undergo a merge. | |
501 | */ | |
502 | struct bfq_iocq_bfqq_data bfqq_data[BFQ_MAX_ACTUATORS]; | |
a6123047 | 503 | |
f9506673 | 504 | unsigned int requests; /* Number of requests this process has in flight */ |
ea25da48 PV |
505 | }; |
506 | ||
ea25da48 PV |
507 | /** |
508 | * struct bfq_data - per-device data structure. | |
509 | * | |
510 | * All the fields are protected by @lock. | |
511 | */ | |
512 | struct bfq_data { | |
513 | /* device request queue */ | |
514 | struct request_queue *queue; | |
515 | /* dispatch queue */ | |
516 | struct list_head dispatch; | |
517 | ||
518 | /* root bfq_group for the device */ | |
519 | struct bfq_group *root_group; | |
520 | ||
521 | /* | |
522 | * rbtree of weight counters of @bfq_queues, sorted by | |
523 | * weight. Used to keep track of whether all @bfq_queues have | |
524 | * the same weight. The tree contains one counter for each | |
525 | * distinct weight associated to some active and not | |
526 | * weight-raised @bfq_queue (see the comments to the functions | |
527 | * bfq_weights_tree_[add|remove] for further details). | |
528 | */ | |
fb53ac6c | 529 | struct rb_root_cached queue_weights_tree; |
ba7aeae5 | 530 | |
1eb20620 | 531 | #ifdef CONFIG_BFQ_GROUP_IOSCHED |
ea25da48 | 532 | /* |
71f8ca77 | 533 | * Number of groups with at least one process that |
ba7aeae5 PV |
534 | * has at least one request waiting for completion. Note that |
535 | * this accounts for also requests already dispatched, but not | |
536 | * yet completed. Therefore this number of groups may differ | |
537 | * (be larger) than the number of active groups, as a group is | |
538 | * considered active only if its corresponding entity has | |
71f8ca77 | 539 | * queues with at least one request queued. This |
ba7aeae5 PV |
540 | * number is used to decide whether a scenario is symmetric. |
541 | * For a detailed explanation see comments on the computation | |
542 | * of the variable asymmetric_scenario in the function | |
543 | * bfq_better_to_idle(). | |
544 | * | |
545 | * However, it is hard to compute this number exactly, for | |
71f8ca77 YK |
546 | * groups with multiple processes. Consider a group |
547 | * that is inactive, i.e., that has no process with | |
ba7aeae5 PV |
548 | * pending I/O inside BFQ queues. Then suppose that |
549 | * num_groups_with_pending_reqs is still accounting for this | |
71f8ca77 | 550 | * group, because the group has processes with some |
ba7aeae5 PV |
551 | * I/O request still in flight. num_groups_with_pending_reqs |
552 | * should be decremented when the in-flight request of the | |
71f8ca77 | 553 | * last process is finally completed (assuming that |
ba7aeae5 PV |
554 | * nothing else has changed for the group in the meantime, in |
555 | * terms of composition of the group and active/inactive state of child | |
556 | * groups and processes). To accomplish this, an additional | |
557 | * pending-request counter must be added to entities, and must | |
558 | * be updated correctly. To avoid this additional field and operations, | |
559 | * we resort to the following tradeoff between simplicity and | |
560 | * accuracy: for an inactive group that is still counted in | |
561 | * num_groups_with_pending_reqs, we decrement | |
71f8ca77 | 562 | * num_groups_with_pending_reqs when the first |
ba7aeae5 PV |
563 | * process of the group remains with no request waiting for |
564 | * completion. | |
565 | * | |
566 | * Even this simpler decrement strategy requires a little | |
567 | * carefulness: to avoid multiple decrements, we flag a group, | |
568 | * more precisely an entity representing a group, as still | |
569 | * counted in num_groups_with_pending_reqs when it becomes | |
71f8ca77 | 570 | * inactive. Then, when the first queue of the |
ba7aeae5 PV |
571 | * entity remains with no request waiting for completion, |
572 | * num_groups_with_pending_reqs is decremented, and this flag | |
573 | * is reset. After this flag is reset for the entity, | |
574 | * num_groups_with_pending_reqs won't be decremented any | |
71f8ca77 | 575 | * longer in case a new queue of the entity remains |
ba7aeae5 | 576 | * with no request waiting for completion. |
ea25da48 | 577 | */ |
ba7aeae5 | 578 | unsigned int num_groups_with_pending_reqs; |
1eb20620 | 579 | #endif |
ea25da48 PV |
580 | |
581 | /* | |
73d58118 PV |
582 | * Per-class (RT, BE, IDLE) number of bfq_queues containing |
583 | * requests (including the queue in service, even if it is | |
584 | * idling). | |
ea25da48 | 585 | */ |
73d58118 | 586 | unsigned int busy_queues[3]; |
ea25da48 PV |
587 | /* number of weight-raised busy @bfq_queues */ |
588 | int wr_busy_queues; | |
589 | /* number of queued requests */ | |
590 | int queued; | |
591 | /* number of requests dispatched and waiting for completion */ | |
2d31c684 DZ |
592 | int tot_rq_in_driver; |
593 | /* | |
594 | * number of requests dispatched and waiting for completion | |
595 | * for each actuator | |
596 | */ | |
597 | int rq_in_driver[BFQ_MAX_ACTUATORS]; | |
ea25da48 | 598 | |
8cacc5ab PV |
599 | /* true if the device is non rotational and performs queueing */ |
600 | bool nonrot_with_queueing; | |
601 | ||
ea25da48 PV |
602 | /* |
603 | * Maximum number of requests in driver in the last | |
604 | * @hw_tag_samples completed requests. | |
605 | */ | |
606 | int max_rq_in_driver; | |
607 | /* number of samples used to calculate hw_tag */ | |
608 | int hw_tag_samples; | |
609 | /* flag set to one if the driver is showing a queueing behavior */ | |
610 | int hw_tag; | |
611 | ||
612 | /* number of budgets assigned */ | |
613 | int budgets_assigned; | |
614 | ||
615 | /* | |
616 | * Timer set when idling (waiting) for the next request from | |
617 | * the queue in service. | |
618 | */ | |
619 | struct hrtimer idle_slice_timer; | |
620 | ||
621 | /* bfq_queue in service */ | |
622 | struct bfq_queue *in_service_queue; | |
623 | ||
624 | /* on-disk position of the last served request */ | |
625 | sector_t last_position; | |
626 | ||
058fdecc PV |
627 | /* position of the last served request for the in-service queue */ |
628 | sector_t in_serv_last_pos; | |
629 | ||
ea25da48 PV |
630 | /* time of last request completion (ns) */ |
631 | u64 last_completion; | |
632 | ||
13a857a4 PV |
633 | /* bfqq owning the last completed rq */ |
634 | struct bfq_queue *last_completed_rq_bfqq; | |
635 | ||
430a67f9 PV |
636 | /* last bfqq created, among those in the root group */ |
637 | struct bfq_queue *last_bfqq_created; | |
638 | ||
2341d662 PV |
639 | /* time of last transition from empty to non-empty (ns) */ |
640 | u64 last_empty_occupied_ns; | |
641 | ||
642 | /* | |
643 | * Flag set to activate the sampling of the total service time | |
644 | * of a just-arrived first I/O request (see | |
645 | * bfq_update_inject_limit()). This will cause the setting of | |
646 | * waited_rq when the request is finally dispatched. | |
647 | */ | |
648 | bool wait_dispatch; | |
649 | /* | |
650 | * If set, then bfq_update_inject_limit() is invoked when | |
651 | * waited_rq is eventually completed. | |
652 | */ | |
653 | struct request *waited_rq; | |
654 | /* | |
655 | * True if some request has been injected during the last service hole. | |
656 | */ | |
657 | bool rqs_injected; | |
658 | ||
ea25da48 PV |
659 | /* time of first rq dispatch in current observation interval (ns) */ |
660 | u64 first_dispatch; | |
661 | /* time of last rq dispatch in current observation interval (ns) */ | |
662 | u64 last_dispatch; | |
663 | ||
664 | /* beginning of the last budget */ | |
665 | ktime_t last_budget_start; | |
666 | /* beginning of the last idle slice */ | |
667 | ktime_t last_idling_start; | |
2341d662 | 668 | unsigned long last_idling_start_jiffies; |
ea25da48 PV |
669 | |
670 | /* number of samples in current observation interval */ | |
671 | int peak_rate_samples; | |
672 | /* num of samples of seq dispatches in current observation interval */ | |
673 | u32 sequential_samples; | |
674 | /* total num of sectors transferred in current observation interval */ | |
675 | u64 tot_sectors_dispatched; | |
676 | /* max rq size seen during current observation interval (sectors) */ | |
677 | u32 last_rq_max_size; | |
678 | /* time elapsed from first dispatch in current observ. interval (us) */ | |
679 | u64 delta_from_first; | |
680 | /* | |
681 | * Current estimate of the device peak rate, measured in | |
bc56e2ca | 682 | * [(sectors/usec) / 2^BFQ_RATE_SHIFT]. The left-shift by |
ea25da48 PV |
683 | * BFQ_RATE_SHIFT is performed to increase precision in |
684 | * fixed-point calculations. | |
685 | */ | |
686 | u32 peak_rate; | |
687 | ||
688 | /* maximum budget allotted to a bfq_queue before rescheduling */ | |
689 | int bfq_max_budget; | |
690 | ||
2d31c684 DZ |
691 | /* |
692 | * List of all the bfq_queues active for a specific actuator | |
693 | * on the device. Keeping active queues separate on a | |
694 | * per-actuator basis helps implementing per-actuator | |
695 | * injection more efficiently. | |
696 | */ | |
697 | struct list_head active_list[BFQ_MAX_ACTUATORS]; | |
ea25da48 PV |
698 | /* list of all the bfq_queues idle on the device */ |
699 | struct list_head idle_list; | |
700 | ||
701 | /* | |
702 | * Timeout for async/sync requests; when it fires, requests | |
703 | * are served in fifo order. | |
704 | */ | |
705 | u64 bfq_fifo_expire[2]; | |
706 | /* weight of backward seeks wrt forward ones */ | |
707 | unsigned int bfq_back_penalty; | |
708 | /* maximum allowed backward seek */ | |
709 | unsigned int bfq_back_max; | |
710 | /* maximum idling time */ | |
711 | u32 bfq_slice_idle; | |
712 | ||
713 | /* user-configured max budget value (0 for auto-tuning) */ | |
714 | int bfq_user_max_budget; | |
715 | /* | |
716 | * Timeout for bfq_queues to consume their budget; used to | |
717 | * prevent seeky queues from imposing long latencies to | |
718 | * sequential or quasi-sequential ones (this also implies that | |
719 | * seeky queues cannot receive guarantees in the service | |
720 | * domain; after a timeout they are charged for the time they | |
721 | * have been in service, to preserve fairness among them, but | |
722 | * without service-domain guarantees). | |
723 | */ | |
724 | unsigned int bfq_timeout; | |
725 | ||
ea25da48 PV |
726 | /* |
727 | * Force device idling whenever needed to provide accurate | |
728 | * service guarantees, without caring about throughput | |
729 | * issues. CAVEAT: this may even increase latencies, in case | |
730 | * of useless idling for processes that did stop doing I/O. | |
731 | */ | |
732 | bool strict_guarantees; | |
733 | ||
734 | /* | |
735 | * Last time at which a queue entered the current burst of | |
736 | * queues being activated shortly after each other; for more | |
737 | * details about this and the following parameters related to | |
738 | * a burst of activations, see the comments on the function | |
739 | * bfq_handle_burst. | |
740 | */ | |
741 | unsigned long last_ins_in_burst; | |
742 | /* | |
743 | * Reference time interval used to decide whether a queue has | |
744 | * been activated shortly after @last_ins_in_burst. | |
745 | */ | |
746 | unsigned long bfq_burst_interval; | |
747 | /* number of queues in the current burst of queue activations */ | |
748 | int burst_size; | |
749 | ||
750 | /* common parent entity for the queues in the burst */ | |
751 | struct bfq_entity *burst_parent_entity; | |
752 | /* Maximum burst size above which the current queue-activation | |
753 | * burst is deemed as 'large'. | |
754 | */ | |
755 | unsigned long bfq_large_burst_thresh; | |
756 | /* true if a large queue-activation burst is in progress */ | |
757 | bool large_burst; | |
758 | /* | |
759 | * Head of the burst list (as for the above fields, more | |
760 | * details in the comments on the function bfq_handle_burst). | |
761 | */ | |
762 | struct hlist_head burst_list; | |
763 | ||
764 | /* if set to true, low-latency heuristics are enabled */ | |
765 | bool low_latency; | |
766 | /* | |
767 | * Maximum factor by which the weight of a weight-raised queue | |
768 | * is multiplied. | |
769 | */ | |
770 | unsigned int bfq_wr_coeff; | |
ea25da48 PV |
771 | |
772 | /* Maximum weight-raising duration for soft real-time processes */ | |
773 | unsigned int bfq_wr_rt_max_time; | |
774 | /* | |
775 | * Minimum idle period after which weight-raising may be | |
776 | * reactivated for a queue (in jiffies). | |
777 | */ | |
778 | unsigned int bfq_wr_min_idle_time; | |
779 | /* | |
780 | * Minimum period between request arrivals after which | |
781 | * weight-raising may be reactivated for an already busy async | |
782 | * queue (in jiffies). | |
783 | */ | |
784 | unsigned long bfq_wr_min_inter_arr_async; | |
785 | ||
786 | /* Max service-rate for a soft real-time queue, in sectors/sec */ | |
787 | unsigned int bfq_wr_max_softrt_rate; | |
788 | /* | |
e24f1c24 PV |
789 | * Cached value of the product ref_rate*ref_wr_duration, used |
790 | * for computing the maximum duration of weight raising | |
791 | * automatically. | |
ea25da48 | 792 | */ |
e24f1c24 | 793 | u64 rate_dur_prod; |
ea25da48 PV |
794 | |
795 | /* fallback dummy bfqq for extreme OOM conditions */ | |
796 | struct bfq_queue oom_bfqq; | |
797 | ||
798 | spinlock_t lock; | |
799 | ||
800 | /* | |
801 | * bic associated with the task issuing current bio for | |
802 | * merging. This and the next field are used as a support to | |
803 | * be able to perform the bic lookup, needed by bio-merge | |
804 | * functions, before the scheduler lock is taken, and thus | |
805 | * avoid taking the request-queue lock while the scheduler | |
806 | * lock is being held. | |
807 | */ | |
808 | struct bfq_io_cq *bio_bic; | |
809 | /* bfqq associated with the task issuing current bio for merging */ | |
810 | struct bfq_queue *bio_bfqq; | |
a52a69ea | 811 | |
a52a69ea PV |
812 | /* |
813 | * Depth limits used in bfq_limit_depth (see comments on the | |
814 | * function) | |
815 | */ | |
816 | unsigned int word_depths[2][2]; | |
44dfa279 | 817 | unsigned int full_depth_shift; |
9778369a PV |
818 | |
819 | /* | |
820 | * Number of independent actuators. This is equal to 1 in | |
821 | * case of single-actuator drives. | |
822 | */ | |
823 | unsigned int num_actuators; | |
4fdb3b9f FG |
824 | /* |
825 | * Disk independent access ranges for each actuator | |
826 | * in this device. | |
827 | */ | |
828 | sector_t sector[BFQ_MAX_ACTUATORS]; | |
829 | sector_t nr_sectors[BFQ_MAX_ACTUATORS]; | |
830 | struct blk_independent_access_range ia_ranges[BFQ_MAX_ACTUATORS]; | |
2d31c684 DZ |
831 | |
832 | /* | |
833 | * If the number of I/O requests queued in the device for a | |
834 | * given actuator is below next threshold, then the actuator | |
835 | * is deemed as underutilized. If this condition is found to | |
836 | * hold for some actuator upon a dispatch, but (i) the | |
837 | * in-service queue does not contain I/O for that actuator, | |
838 | * while (ii) some other queue does contain I/O for that | |
839 | * actuator, then the head I/O request of the latter queue is | |
840 | * returned (injected), instead of the head request of the | |
841 | * currently in-service queue. | |
842 | * | |
843 | * We set the threshold, empirically, to the minimum possible | |
844 | * value for which an actuator is fully utilized, or close to | |
845 | * be fully utilized. By doing so, injected I/O 'steals' as | |
846 | * few drive-queue slots as possibile to the in-service | |
847 | * queue. This reduces as much as possible the probability | |
848 | * that the service of I/O from the in-service bfq_queue gets | |
849 | * delayed because of slot exhaustion, i.e., because all the | |
850 | * slots of the drive queue are filled with I/O injected from | |
851 | * other queues (NCQ provides for 32 slots). | |
852 | */ | |
853 | unsigned int actuator_load_threshold; | |
ea25da48 PV |
854 | }; |
855 | ||
856 | enum bfqq_state_flags { | |
857 | BFQQF_just_created = 0, /* queue just allocated */ | |
858 | BFQQF_busy, /* has requests or is in service */ | |
859 | BFQQF_wait_request, /* waiting for a request */ | |
860 | BFQQF_non_blocking_wait_rq, /* | |
861 | * waiting for a request | |
862 | * without idling the device | |
863 | */ | |
864 | BFQQF_fifo_expire, /* FIFO checked in this slice */ | |
d5be3fef | 865 | BFQQF_has_short_ttime, /* queue has a short think time */ |
ea25da48 PV |
866 | BFQQF_sync, /* synchronous queue */ |
867 | BFQQF_IO_bound, /* | |
868 | * bfqq has timed-out at least once | |
869 | * having consumed at most 2/10 of | |
870 | * its budget | |
871 | */ | |
872 | BFQQF_in_large_burst, /* | |
873 | * bfqq activated in a large burst, | |
874 | * see comments to bfq_handle_burst. | |
875 | */ | |
876 | BFQQF_softrt_update, /* | |
877 | * may need softrt-next-start | |
878 | * update | |
879 | */ | |
880 | BFQQF_coop, /* bfqq is shared */ | |
13a857a4 | 881 | BFQQF_split_coop, /* shared bfqq will be split */ |
ea25da48 PV |
882 | }; |
883 | ||
884 | #define BFQ_BFQQ_FNS(name) \ | |
885 | void bfq_mark_bfqq_##name(struct bfq_queue *bfqq); \ | |
886 | void bfq_clear_bfqq_##name(struct bfq_queue *bfqq); \ | |
887 | int bfq_bfqq_##name(const struct bfq_queue *bfqq); | |
888 | ||
889 | BFQ_BFQQ_FNS(just_created); | |
890 | BFQ_BFQQ_FNS(busy); | |
891 | BFQ_BFQQ_FNS(wait_request); | |
892 | BFQ_BFQQ_FNS(non_blocking_wait_rq); | |
893 | BFQ_BFQQ_FNS(fifo_expire); | |
d5be3fef | 894 | BFQ_BFQQ_FNS(has_short_ttime); |
ea25da48 PV |
895 | BFQ_BFQQ_FNS(sync); |
896 | BFQ_BFQQ_FNS(IO_bound); | |
897 | BFQ_BFQQ_FNS(in_large_burst); | |
898 | BFQ_BFQQ_FNS(coop); | |
899 | BFQ_BFQQ_FNS(split_coop); | |
900 | BFQ_BFQQ_FNS(softrt_update); | |
901 | #undef BFQ_BFQQ_FNS | |
902 | ||
903 | /* Expiration reasons. */ | |
904 | enum bfqq_expiration { | |
905 | BFQQE_TOO_IDLE = 0, /* | |
906 | * queue has been idling for | |
907 | * too long | |
908 | */ | |
909 | BFQQE_BUDGET_TIMEOUT, /* budget took too long to be used */ | |
910 | BFQQE_BUDGET_EXHAUSTED, /* budget consumed */ | |
911 | BFQQE_NO_MORE_REQUESTS, /* the queue has no more requests */ | |
912 | BFQQE_PREEMPTED /* preemption in progress */ | |
913 | }; | |
914 | ||
c0ce79dc CH |
915 | struct bfq_stat { |
916 | struct percpu_counter cpu_cnt; | |
917 | atomic64_t aux_cnt; | |
918 | }; | |
919 | ||
ea25da48 | 920 | struct bfqg_stats { |
fd41e603 TH |
921 | /* basic stats */ |
922 | struct blkg_rwstat bytes; | |
923 | struct blkg_rwstat ios; | |
8060c47b | 924 | #ifdef CONFIG_BFQ_CGROUP_DEBUG |
ea25da48 PV |
925 | /* number of ios merged */ |
926 | struct blkg_rwstat merged; | |
927 | /* total time spent on device in ns, may not be accurate w/ queueing */ | |
928 | struct blkg_rwstat service_time; | |
929 | /* total time spent waiting in scheduler queue in ns */ | |
930 | struct blkg_rwstat wait_time; | |
931 | /* number of IOs queued up */ | |
932 | struct blkg_rwstat queued; | |
933 | /* total disk time and nr sectors dispatched by this group */ | |
c0ce79dc | 934 | struct bfq_stat time; |
ea25da48 | 935 | /* sum of number of ios queued across all samples */ |
c0ce79dc | 936 | struct bfq_stat avg_queue_size_sum; |
ea25da48 | 937 | /* count of samples taken for average */ |
c0ce79dc | 938 | struct bfq_stat avg_queue_size_samples; |
ea25da48 | 939 | /* how many times this group has been removed from service tree */ |
c0ce79dc | 940 | struct bfq_stat dequeue; |
ea25da48 | 941 | /* total time spent waiting for it to be assigned a timeslice. */ |
c0ce79dc | 942 | struct bfq_stat group_wait_time; |
ea25da48 | 943 | /* time spent idling for this blkcg_gq */ |
c0ce79dc | 944 | struct bfq_stat idle_time; |
ea25da48 | 945 | /* total time with empty current active q with other requests queued */ |
c0ce79dc | 946 | struct bfq_stat empty_time; |
ea25da48 | 947 | /* fields after this shouldn't be cleared on stat reset */ |
84c7afce OS |
948 | u64 start_group_wait_time; |
949 | u64 start_idle_time; | |
950 | u64 start_empty_time; | |
ea25da48 | 951 | uint16_t flags; |
8060c47b | 952 | #endif /* CONFIG_BFQ_CGROUP_DEBUG */ |
ea25da48 PV |
953 | }; |
954 | ||
955 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
956 | ||
957 | /* | |
958 | * struct bfq_group_data - per-blkcg storage for the blkio subsystem. | |
959 | * | |
960 | * @ps: @blkcg_policy_storage that this structure inherits | |
961 | * @weight: weight of the bfq_group | |
962 | */ | |
963 | struct bfq_group_data { | |
964 | /* must be the first member */ | |
965 | struct blkcg_policy_data pd; | |
966 | ||
967 | unsigned int weight; | |
968 | }; | |
969 | ||
970 | /** | |
971 | * struct bfq_group - per (device, cgroup) data structure. | |
972 | * @entity: schedulable entity to insert into the parent group sched_data. | |
973 | * @sched_data: own sched_data, to contain child entities (they may be | |
974 | * both bfq_queues and bfq_groups). | |
975 | * @bfqd: the bfq_data for the device this group acts upon. | |
976 | * @async_bfqq: array of async queues for all the tasks belonging to | |
977 | * the group, one queue per ioprio value per ioprio_class, | |
978 | * except for the idle class that has only one queue. | |
979 | * @async_idle_bfqq: async queue for the idle class (ioprio is ignored). | |
980 | * @my_entity: pointer to @entity, %NULL for the toplevel group; used | |
981 | * to avoid too many special cases during group creation/ | |
982 | * migration. | |
983 | * @stats: stats for this bfqg. | |
984 | * @active_entities: number of active entities belonging to the group; | |
985 | * unused for the root group. Used to know whether there | |
986 | * are groups with more than one active @bfq_entity | |
987 | * (see the comments to the function | |
988 | * bfq_bfqq_may_idle()). | |
989 | * @rq_pos_tree: rbtree sorted by next_request position, used when | |
990 | * determining if two or more queues have interleaving | |
991 | * requests (see bfq_find_close_cooperator()). | |
992 | * | |
993 | * Each (device, cgroup) pair has its own bfq_group, i.e., for each cgroup | |
994 | * there is a set of bfq_groups, each one collecting the lower-level | |
995 | * entities belonging to the group that are acting on the same device. | |
996 | * | |
997 | * Locking works as follows: | |
998 | * o @bfqd is protected by the queue lock, RCU is used to access it | |
999 | * from the readers. | |
1000 | * o All the other fields are protected by the @bfqd queue lock. | |
1001 | */ | |
1002 | struct bfq_group { | |
1003 | /* must be the first member */ | |
1004 | struct blkg_policy_data pd; | |
1005 | ||
8f9bebc3 PV |
1006 | /* cached path for this blkg (see comments in bfq_bic_update_cgroup) */ |
1007 | char blkg_path[128]; | |
1008 | ||
1009 | /* reference counter (see comments in bfq_bic_update_cgroup) */ | |
216f7647 | 1010 | refcount_t ref; |
8f9bebc3 | 1011 | |
ea25da48 PV |
1012 | struct bfq_entity entity; |
1013 | struct bfq_sched_data sched_data; | |
1014 | ||
aa625117 | 1015 | struct bfq_data *bfqd; |
ea25da48 | 1016 | |
8b7fd741 DZ |
1017 | struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS][BFQ_MAX_ACTUATORS]; |
1018 | struct bfq_queue *async_idle_bfqq[BFQ_MAX_ACTUATORS]; | |
ea25da48 PV |
1019 | |
1020 | struct bfq_entity *my_entity; | |
1021 | ||
1022 | int active_entities; | |
60a6e10c | 1023 | int num_queues_with_pending_reqs; |
ea25da48 PV |
1024 | |
1025 | struct rb_root rq_pos_tree; | |
1026 | ||
1027 | struct bfqg_stats stats; | |
1028 | }; | |
1029 | ||
1030 | #else | |
1031 | struct bfq_group { | |
4d8340d0 | 1032 | struct bfq_entity entity; |
ea25da48 PV |
1033 | struct bfq_sched_data sched_data; |
1034 | ||
8b7fd741 DZ |
1035 | struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS][BFQ_MAX_ACTUATORS]; |
1036 | struct bfq_queue *async_idle_bfqq[BFQ_MAX_ACTUATORS]; | |
ea25da48 PV |
1037 | |
1038 | struct rb_root rq_pos_tree; | |
1039 | }; | |
1040 | #endif | |
1041 | ||
ea25da48 PV |
1042 | /* --------------- main algorithm interface ----------------- */ |
1043 | ||
1044 | #define BFQ_SERVICE_TREE_INIT ((struct bfq_service_tree) \ | |
1045 | { RB_ROOT, RB_ROOT, NULL, NULL, 0, 0 }) | |
1046 | ||
1047 | extern const int bfq_timeout; | |
1048 | ||
9778369a PV |
1049 | struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync, |
1050 | unsigned int actuator_idx); | |
1051 | void bic_set_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq, bool is_sync, | |
1052 | unsigned int actuator_idx); | |
ea25da48 | 1053 | struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic); |
ea25da48 | 1054 | void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq); |
afdba146 | 1055 | void bfq_weights_tree_add(struct bfq_queue *bfqq); |
afdba146 | 1056 | void bfq_weights_tree_remove(struct bfq_queue *bfqq); |
ea25da48 PV |
1057 | void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1058 | bool compensate, enum bfqq_expiration reason); | |
1059 | void bfq_put_queue(struct bfq_queue *bfqq); | |
3bc5e683 | 1060 | void bfq_put_cooperator(struct bfq_queue *bfqq); |
ea25da48 | 1061 | void bfq_end_wr_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); |
c8997736 | 1062 | void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq); |
ea25da48 PV |
1063 | void bfq_schedule_dispatch(struct bfq_data *bfqd); |
1064 | void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); | |
1065 | ||
1066 | /* ------------ end of main algorithm interface -------------- */ | |
1067 | ||
1068 | /* ---------------- cgroups-support interface ---------------- */ | |
1069 | ||
fd41e603 | 1070 | void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq); |
dc469ba2 BVA |
1071 | void bfqg_stats_update_io_remove(struct bfq_group *bfqg, blk_opf_t opf); |
1072 | void bfqg_stats_update_io_merged(struct bfq_group *bfqg, blk_opf_t opf); | |
84c7afce | 1073 | void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns, |
dc469ba2 | 1074 | u64 io_start_time_ns, blk_opf_t opf); |
ea25da48 | 1075 | void bfqg_stats_update_dequeue(struct bfq_group *bfqg); |
ea25da48 | 1076 | void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg); |
ea25da48 PV |
1077 | void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1078 | struct bfq_group *bfqg); | |
1079 | ||
c2090eab YK |
1080 | #ifdef CONFIG_BFQ_CGROUP_DEBUG |
1081 | void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq, | |
1082 | blk_opf_t opf); | |
1083 | void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg); | |
1084 | void bfqg_stats_update_idle_time(struct bfq_group *bfqg); | |
1085 | void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg); | |
1086 | #endif | |
1087 | ||
ea25da48 PV |
1088 | void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg); |
1089 | void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio); | |
1090 | void bfq_end_wr_async(struct bfq_data *bfqd); | |
4e54a249 | 1091 | struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio); |
ea25da48 PV |
1092 | struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg); |
1093 | struct bfq_group *bfqq_group(struct bfq_queue *bfqq); | |
1094 | struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node); | |
8f9bebc3 | 1095 | void bfqg_and_blkg_put(struct bfq_group *bfqg); |
ea25da48 PV |
1096 | |
1097 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
659b3394 JA |
1098 | extern struct cftype bfq_blkcg_legacy_files[]; |
1099 | extern struct cftype bfq_blkg_files[]; | |
ea25da48 PV |
1100 | extern struct blkcg_policy blkcg_policy_bfq; |
1101 | #endif | |
1102 | ||
1103 | /* ------------- end of cgroups-support interface ------------- */ | |
1104 | ||
1105 | /* - interface of the internal hierarchical B-WF2Q+ scheduler - */ | |
1106 | ||
1107 | #ifdef CONFIG_BFQ_GROUP_IOSCHED | |
1108 | /* both next loops stop at one of the child entities of the root group */ | |
1109 | #define for_each_entity(entity) \ | |
1110 | for (; entity ; entity = entity->parent) | |
1111 | ||
1112 | /* | |
1113 | * For each iteration, compute parent in advance, so as to be safe if | |
1114 | * entity is deallocated during the iteration. Such a deallocation may | |
1115 | * happen as a consequence of a bfq_put_queue that frees the bfq_queue | |
1116 | * containing entity. | |
1117 | */ | |
1118 | #define for_each_entity_safe(entity, parent) \ | |
1119 | for (; entity && ({ parent = entity->parent; 1; }); entity = parent) | |
1120 | ||
1121 | #else /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1122 | /* | |
1123 | * Next two macros are fake loops when cgroups support is not | |
1124 | * enabled. I fact, in such a case, there is only one level to go up | |
1125 | * (to reach the root group). | |
1126 | */ | |
1127 | #define for_each_entity(entity) \ | |
1128 | for (; entity ; entity = NULL) | |
1129 | ||
1130 | #define for_each_entity_safe(entity, parent) \ | |
1131 | for (parent = NULL; entity ; entity = parent) | |
1132 | #endif /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1133 | ||
ea25da48 | 1134 | struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity); |
73d58118 | 1135 | unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd); |
ea25da48 PV |
1136 | struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity); |
1137 | struct bfq_entity *bfq_entity_of(struct rb_node *node); | |
1138 | unsigned short bfq_ioprio_to_weight(int ioprio); | |
1139 | void bfq_put_idle_entity(struct bfq_service_tree *st, | |
1140 | struct bfq_entity *entity); | |
1141 | struct bfq_service_tree * | |
1142 | __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st, | |
431b17f9 PV |
1143 | struct bfq_entity *entity, |
1144 | bool update_class_too); | |
ea25da48 PV |
1145 | void bfq_bfqq_served(struct bfq_queue *bfqq, int served); |
1146 | void bfq_bfqq_charge_time(struct bfq_data *bfqd, struct bfq_queue *bfqq, | |
1147 | unsigned long time_ms); | |
1148 | bool __bfq_deactivate_entity(struct bfq_entity *entity, | |
1149 | bool ins_into_idle_tree); | |
1150 | bool next_queue_may_preempt(struct bfq_data *bfqd); | |
1151 | struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd); | |
eed47d19 | 1152 | bool __bfq_bfqd_reset_in_service(struct bfq_data *bfqd); |
ea25da48 PV |
1153 | void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1154 | bool ins_into_idle_tree, bool expiration); | |
1155 | void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq); | |
80294c3b PV |
1156 | void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1157 | bool expiration); | |
d322f355 YK |
1158 | void bfq_del_bfqq_busy(struct bfq_queue *bfqq, bool expiration); |
1159 | void bfq_add_bfqq_busy(struct bfq_queue *bfqq); | |
3d89bd12 YK |
1160 | void bfq_add_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq); |
1161 | void bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq); | |
ea25da48 PV |
1162 | |
1163 | /* --------------- end of interface of B-WF2Q+ ---------------- */ | |
1164 | ||
1165 | /* Logging facilities. */ | |
582f04e1 | 1166 | static inline void bfq_bfqq_name(struct bfq_queue *bfqq, char *str, int len) |
1e66413c | 1167 | { |
582f04e1 JK |
1168 | char type = bfq_bfqq_sync(bfqq) ? 'S' : 'A'; |
1169 | ||
1170 | if (bfqq->pid != -1) | |
1171 | snprintf(str, len, "bfq%d%c", bfqq->pid, type); | |
1e66413c | 1172 | else |
582f04e1 | 1173 | snprintf(str, len, "bfqSHARED-%c", type); |
1e66413c FP |
1174 | } |
1175 | ||
ea25da48 PV |
1176 | #ifdef CONFIG_BFQ_GROUP_IOSCHED |
1177 | struct bfq_group *bfqq_group(struct bfq_queue *bfqq); | |
1178 | ||
1179 | #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ | |
582f04e1 | 1180 | char pid_str[MAX_BFQQ_NAME_LENGTH]; \ |
40d47c15 DM |
1181 | if (likely(!blk_trace_note_message_enabled((bfqd)->queue))) \ |
1182 | break; \ | |
582f04e1 | 1183 | bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH); \ |
35fe6d76 | 1184 | blk_add_cgroup_trace_msg((bfqd)->queue, \ |
f4a6a61c | 1185 | &bfqg_to_blkg(bfqq_group(bfqq))->blkcg->css, \ |
582f04e1 | 1186 | "%s " fmt, pid_str, ##args); \ |
ea25da48 PV |
1187 | } while (0) |
1188 | ||
35fe6d76 SL |
1189 | #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do { \ |
1190 | blk_add_cgroup_trace_msg((bfqd)->queue, \ | |
f4a6a61c | 1191 | &bfqg_to_blkg(bfqg)->blkcg->css, fmt, ##args); \ |
35fe6d76 | 1192 | } while (0) |
ea25da48 PV |
1193 | |
1194 | #else /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1195 | ||
1e66413c | 1196 | #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \ |
582f04e1 | 1197 | char pid_str[MAX_BFQQ_NAME_LENGTH]; \ |
40d47c15 DM |
1198 | if (likely(!blk_trace_note_message_enabled((bfqd)->queue))) \ |
1199 | break; \ | |
582f04e1 JK |
1200 | bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH); \ |
1201 | blk_add_trace_msg((bfqd)->queue, "%s " fmt, pid_str, ##args); \ | |
1e66413c | 1202 | } while (0) |
ea25da48 PV |
1203 | #define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do {} while (0) |
1204 | ||
1205 | #endif /* CONFIG_BFQ_GROUP_IOSCHED */ | |
1206 | ||
1207 | #define bfq_log(bfqd, fmt, args...) \ | |
1208 | blk_add_trace_msg((bfqd)->queue, "bfq " fmt, ##args) | |
1209 | ||
1210 | #endif /* _BFQ_H */ |