1  /* SPDX-License-Identifier: GPL-2.0-or-later */
2  /*
3   * Header file for the BFQ I/O scheduler: data structures and
4   * prototypes of interface functions among BFQ components.
5   */
6  #ifndef _BFQ_H
7  #define _BFQ_H
8  
9  #include <linux/blktrace_api.h>
10  #include <linux/hrtimer.h>
11  
12  #include "blk-cgroup-rwstat.h"
13  
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_DEFAULT_GRP_IOPRIO	0
24  #define BFQ_DEFAULT_GRP_CLASS	IOPRIO_CLASS_BE
25  
26  #define MAX_BFQQ_NAME_LENGTH 16
27  
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  
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  
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;
56  	/* tree for idle entities (i.e., not backlogged, with V < F_i)*/
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
75   * intermediate queue in a hierarchical setup.
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+.
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
93   * service among the other active entities in the same parent
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.
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  /**
112   * struct bfq_weight_counter - counter of the number of all active queues
113   *                             with a given weight.
114   */
115  struct bfq_weight_counter {
116  	unsigned int weight; /* weight of the queues this counter refers to */
117  	unsigned int num_active; /* nr of active queues with this weight */
118  	/*
119  	 * Weights tree member (see bfq_data's @queue_weights_tree)
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
144   * "well-behaved" queues (i.e., queues that do not spend too much
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;
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  	 */
159  	bool on_st_or_in_serv;
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  
179  	/* Number of requests allocated in the subtree of this entity */
180  	int allocated;
181  
182  	/* device weight, if non-zero, it overrides the default weight of
183  	 * bfq_group_data */
184  	int dev_weight;
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;
206  
207  #ifdef CONFIG_BFQ_GROUP_IOSCHED
208  	/* flag, set if the entity is counted in groups_with_pending_reqs */
209  	bool in_groups_with_pending_reqs;
210  #endif
211  
212  	/* last child queue of entity created (for non-leaf entities) */
213  	struct bfq_queue *last_bfqq_created;
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
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.
245   */
246  struct bfq_queue {
247  	/* reference counter */
248  	int ref;
249  	/* counter of references from other queues for delayed stable merge */
250  	int stable_ref;
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  
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  
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];
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  
290  	/* pointer to the weight counter associated with this entity */
291  	struct bfq_weight_counter *weight_counter;
292  
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  
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  
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;
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;
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 */
381  
382  	unsigned long first_IO_time; /* time of first I/O for this queue */
383  	unsigned long creation_time; /* when this queue is created */
384  
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;
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;
397  	/* time when we started considering this waker */
398  	u64 waker_detection_started;
399  
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;
409  
410  	/* index of the actuator this queue is associated with */
411  	unsigned int actuator_idx;
412  };
413  
414  /**
415  * struct bfq_data - bfqq data unique and persistent for associated bfq_io_cq
416  */
417  struct bfq_iocq_bfqq_data {
418  	/*
419  	 * Snapshot of the has_short_time flag before merging; taken
420  	 * to remember its values while the queue is merged, so as to
421  	 * be able to restore it in case of split.
422  	 */
423  	bool saved_has_short_ttime;
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  
430  	u64 saved_io_start_time;
431  	u64 saved_tot_idle_time;
432  
433  	/*
434  	 * Same purpose as the previous fields for the values of the
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  
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  
453  	/*
454  	 * Similar to previous fields: save wr information.
455  	 */
456  	unsigned long saved_wr_coeff;
457  	unsigned long saved_last_wr_start_finish;
458  	unsigned long saved_service_from_wr;
459  	unsigned long saved_wr_start_at_switch_to_srt;
460  	unsigned int saved_wr_cur_max_time;
461  	struct bfq_ttime saved_ttime;
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;
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 */
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  
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];
503  
504  	unsigned int requests;	/* Number of requests this process has in flight */
505  };
506  
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  	 */
529  	struct rb_root_cached queue_weights_tree;
530  
531  #ifdef CONFIG_BFQ_GROUP_IOSCHED
532  	/*
533  	 * Number of groups with at least one process that
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
539  	 * queues with at least one request queued. This
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
546  	 * groups with multiple processes. Consider a group
547  	 * that is inactive, i.e., that has no process with
548  	 * pending I/O inside BFQ queues. Then suppose that
549  	 * num_groups_with_pending_reqs is still accounting for this
550  	 * group, because the group has processes with some
551  	 * I/O request still in flight. num_groups_with_pending_reqs
552  	 * should be decremented when the in-flight request of the
553  	 * last process is finally completed (assuming that
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
562  	 * num_groups_with_pending_reqs when the first
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
570  	 * inactive. Then, when the first queue of the
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
575  	 * longer in case a new queue of the entity remains
576  	 * with no request waiting for completion.
577  	 */
578  	unsigned int num_groups_with_pending_reqs;
579  #endif
580  
581  	/*
582  	 * Per-class (RT, BE, IDLE) number of bfq_queues containing
583  	 * requests (including the queue in service, even if it is
584  	 * idling).
585  	 */
586  	unsigned int busy_queues[3];
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 */
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];
598  
599  	/* true if the device is non rotational and performs queueing */
600  	bool nonrot_with_queueing;
601  
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  
627  	/* position of the last served request for the in-service queue */
628  	sector_t in_serv_last_pos;
629  
630  	/* time of last request completion (ns) */
631  	u64 last_completion;
632  
633  	/* bfqq owning the last completed rq */
634  	struct bfq_queue *last_completed_rq_bfqq;
635  
636  	/* last bfqq created, among those in the root group */
637  	struct bfq_queue *last_bfqq_created;
638  
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  
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;
668  	unsigned long last_idling_start_jiffies;
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
682  	 * [(sectors/usec) / 2^BFQ_RATE_SHIFT]. The left-shift by
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  
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];
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  
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;
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  	/*
789  	 * Cached value of the product ref_rate*ref_wr_duration, used
790  	 * for computing the maximum duration of weight raising
791  	 * automatically.
792  	 */
793  	u64 rate_dur_prod;
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;
811  
812  	/*
813  	 * Depth limits used in bfq_limit_depth (see comments on the
814  	 * function)
815  	 */
816  	unsigned int word_depths[2][2];
817  	unsigned int full_depth_shift;
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;
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];
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;
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 */
865  	BFQQF_has_short_ttime,	/* queue has a short think time */
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 */
881  	BFQQF_split_coop,	/* shared bfqq will be split */
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);
894  BFQ_BFQQ_FNS(has_short_ttime);
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  
915  struct bfq_stat {
916  	struct percpu_counter		cpu_cnt;
917  	atomic64_t			aux_cnt;
918  };
919  
920  struct bfqg_stats {
921  	/* basic stats */
922  	struct blkg_rwstat		bytes;
923  	struct blkg_rwstat		ios;
924  #ifdef CONFIG_BFQ_CGROUP_DEBUG
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 */
934  	struct bfq_stat		time;
935  	/* sum of number of ios queued across all samples */
936  	struct bfq_stat		avg_queue_size_sum;
937  	/* count of samples taken for average */
938  	struct bfq_stat		avg_queue_size_samples;
939  	/* how many times this group has been removed from service tree */
940  	struct bfq_stat		dequeue;
941  	/* total time spent waiting for it to be assigned a timeslice. */
942  	struct bfq_stat		group_wait_time;
943  	/* time spent idling for this blkcg_gq */
944  	struct bfq_stat		idle_time;
945  	/* total time with empty current active q with other requests queued */
946  	struct bfq_stat		empty_time;
947  	/* fields after this shouldn't be cleared on stat reset */
948  	u64				start_group_wait_time;
949  	u64				start_idle_time;
950  	u64				start_empty_time;
951  	uint16_t			flags;
952  #endif /* CONFIG_BFQ_CGROUP_DEBUG */
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  
1006  	/* reference counter (see comments in bfq_bic_update_cgroup) */
1007  	refcount_t ref;
1008  
1009  	struct bfq_entity entity;
1010  	struct bfq_sched_data sched_data;
1011  
1012  	struct bfq_data *bfqd;
1013  
1014  	struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS][BFQ_MAX_ACTUATORS];
1015  	struct bfq_queue *async_idle_bfqq[BFQ_MAX_ACTUATORS];
1016  
1017  	struct bfq_entity *my_entity;
1018  
1019  	int active_entities;
1020  	int num_queues_with_pending_reqs;
1021  
1022  	struct rb_root rq_pos_tree;
1023  
1024  	struct bfqg_stats stats;
1025  };
1026  
1027  #else
1028  struct bfq_group {
1029  	struct bfq_entity entity;
1030  	struct bfq_sched_data sched_data;
1031  
1032  	struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS][BFQ_MAX_ACTUATORS];
1033  	struct bfq_queue *async_idle_bfqq[BFQ_MAX_ACTUATORS];
1034  
1035  	struct rb_root rq_pos_tree;
1036  };
1037  #endif
1038  
1039  /* --------------- main algorithm interface ----------------- */
1040  
1041  #define BFQ_SERVICE_TREE_INIT	((struct bfq_service_tree)		\
1042  				{ RB_ROOT, RB_ROOT, NULL, NULL, 0, 0 })
1043  
1044  extern const int bfq_timeout;
1045  
1046  struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync,
1047  				unsigned int actuator_idx);
1048  void bic_set_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq, bool is_sync,
1049  				unsigned int actuator_idx);
1050  struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic);
1051  void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq);
1052  void bfq_weights_tree_add(struct bfq_queue *bfqq);
1053  void bfq_weights_tree_remove(struct bfq_queue *bfqq);
1054  void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq,
1055  		     bool compensate, enum bfqq_expiration reason);
1056  void bfq_put_queue(struct bfq_queue *bfqq);
1057  void bfq_put_cooperator(struct bfq_queue *bfqq);
1058  void bfq_end_wr_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg);
1059  void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq);
1060  void bfq_schedule_dispatch(struct bfq_data *bfqd);
1061  void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg);
1062  
1063  /* ------------ end of main algorithm interface -------------- */
1064  
1065  /* ---------------- cgroups-support interface ---------------- */
1066  
1067  void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq);
1068  void bfqg_stats_update_io_remove(struct bfq_group *bfqg, blk_opf_t opf);
1069  void bfqg_stats_update_io_merged(struct bfq_group *bfqg, blk_opf_t opf);
1070  void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns,
1071  				  u64 io_start_time_ns, blk_opf_t opf);
1072  void bfqg_stats_update_dequeue(struct bfq_group *bfqg);
1073  void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg);
1074  void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
1075  		   struct bfq_group *bfqg);
1076  
1077  #ifdef CONFIG_BFQ_CGROUP_DEBUG
1078  void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
1079  			      blk_opf_t opf);
1080  void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg);
1081  void bfqg_stats_update_idle_time(struct bfq_group *bfqg);
1082  void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg);
1083  #endif
1084  
1085  void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg);
1086  void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio);
1087  void bfq_end_wr_async(struct bfq_data *bfqd);
1088  struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio);
1089  struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg);
1090  struct bfq_group *bfqq_group(struct bfq_queue *bfqq);
1091  struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node);
1092  void bfqg_and_blkg_put(struct bfq_group *bfqg);
1093  
1094  #ifdef CONFIG_BFQ_GROUP_IOSCHED
1095  extern struct cftype bfq_blkcg_legacy_files[];
1096  extern struct cftype bfq_blkg_files[];
1097  extern struct blkcg_policy blkcg_policy_bfq;
1098  #endif
1099  
1100  /* ------------- end of cgroups-support interface ------------- */
1101  
1102  /* - interface of the internal hierarchical B-WF2Q+ scheduler - */
1103  
1104  #ifdef CONFIG_BFQ_GROUP_IOSCHED
1105  /* both next loops stop at one of the child entities of the root group */
1106  #define for_each_entity(entity)	\
1107  	for (; entity ; entity = entity->parent)
1108  
1109  /*
1110   * For each iteration, compute parent in advance, so as to be safe if
1111   * entity is deallocated during the iteration. Such a deallocation may
1112   * happen as a consequence of a bfq_put_queue that frees the bfq_queue
1113   * containing entity.
1114   */
1115  #define for_each_entity_safe(entity, parent) \
1116  	for (; entity && ({ parent = entity->parent; 1; }); entity = parent)
1117  
1118  #else /* CONFIG_BFQ_GROUP_IOSCHED */
1119  /*
1120   * Next two macros are fake loops when cgroups support is not
1121   * enabled. I fact, in such a case, there is only one level to go up
1122   * (to reach the root group).
1123   */
1124  #define for_each_entity(entity)	\
1125  	for (; entity ; entity = NULL)
1126  
1127  #define for_each_entity_safe(entity, parent) \
1128  	for (parent = NULL; entity ; entity = parent)
1129  #endif /* CONFIG_BFQ_GROUP_IOSCHED */
1130  
1131  struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity);
1132  unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd);
1133  struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity);
1134  struct bfq_entity *bfq_entity_of(struct rb_node *node);
1135  unsigned short bfq_ioprio_to_weight(int ioprio);
1136  void bfq_put_idle_entity(struct bfq_service_tree *st,
1137  			 struct bfq_entity *entity);
1138  struct bfq_service_tree *
1139  __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st,
1140  				struct bfq_entity *entity,
1141  				bool update_class_too);
1142  void bfq_bfqq_served(struct bfq_queue *bfqq, int served);
1143  void bfq_bfqq_charge_time(struct bfq_data *bfqd, struct bfq_queue *bfqq,
1144  			  unsigned long time_ms);
1145  bool __bfq_deactivate_entity(struct bfq_entity *entity,
1146  			     bool ins_into_idle_tree);
1147  bool next_queue_may_preempt(struct bfq_data *bfqd);
1148  struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd);
1149  bool __bfq_bfqd_reset_in_service(struct bfq_data *bfqd);
1150  void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
1151  			 bool ins_into_idle_tree, bool expiration);
1152  void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq);
1153  void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
1154  		      bool expiration);
1155  void bfq_del_bfqq_busy(struct bfq_queue *bfqq, bool expiration);
1156  void bfq_add_bfqq_busy(struct bfq_queue *bfqq);
1157  void bfq_add_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
1158  void bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
1159  void bfq_reassign_last_bfqq(struct bfq_queue *cur_bfqq,
1160  			    struct bfq_queue *new_bfqq);
1161  
1162  /* --------------- end of interface of B-WF2Q+ ---------------- */
1163  
1164  /* Logging facilities. */
bfq_bfqq_name(struct bfq_queue * bfqq,char * str,int len)1165  static inline void bfq_bfqq_name(struct bfq_queue *bfqq, char *str, int len)
1166  {
1167  	char type = bfq_bfqq_sync(bfqq) ? 'S' : 'A';
1168  
1169  	if (bfqq->pid != -1)
1170  		snprintf(str, len, "bfq%d%c", bfqq->pid, type);
1171  	else
1172  		snprintf(str, len, "bfqSHARED-%c", type);
1173  }
1174  
1175  #ifdef CONFIG_BFQ_GROUP_IOSCHED
1176  struct bfq_group *bfqq_group(struct bfq_queue *bfqq);
1177  
1178  #define bfq_log_bfqq(bfqd, bfqq, fmt, args...)	do {			\
1179  	char pid_str[MAX_BFQQ_NAME_LENGTH];				\
1180  	if (likely(!blk_trace_note_message_enabled((bfqd)->queue)))	\
1181  		break;							\
1182  	bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH);		\
1183  	blk_add_cgroup_trace_msg((bfqd)->queue,				\
1184  			&bfqg_to_blkg(bfqq_group(bfqq))->blkcg->css,	\
1185  			"%s " fmt, pid_str, ##args);			\
1186  } while (0)
1187  
1188  #else /* CONFIG_BFQ_GROUP_IOSCHED */
1189  
1190  #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do {	\
1191  	char pid_str[MAX_BFQQ_NAME_LENGTH];				\
1192  	if (likely(!blk_trace_note_message_enabled((bfqd)->queue)))	\
1193  		break;							\
1194  	bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH);		\
1195  	blk_add_trace_msg((bfqd)->queue, "%s " fmt, pid_str, ##args);	\
1196  } while (0)
1197  
1198  #endif /* CONFIG_BFQ_GROUP_IOSCHED */
1199  
1200  #define bfq_log(bfqd, fmt, args...) \
1201  	blk_add_trace_msg((bfqd)->queue, "bfq " fmt, ##args)
1202  
1203  #endif /* _BFQ_H */
1204