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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef RQ_QOS_H
3#define RQ_QOS_H
4
5#include <linux/kernel.h>
6#include <linux/blkdev.h>
7#include <linux/blk_types.h>
8#include <linux/atomic.h>
9#include <linux/wait.h>
10#include <linux/blk-mq.h>
11
12#include "blk-mq-debugfs.h"
13
14struct blk_mq_debugfs_attr;
15
16enum rq_qos_id {
17 RQ_QOS_WBT,
18 RQ_QOS_LATENCY,
19 RQ_QOS_COST,
20 RQ_QOS_IOPRIO,
21};
22
23struct rq_wait {
24 wait_queue_head_t wait;
25 atomic_t inflight;
26};
27
28struct rq_qos {
29 struct rq_qos_ops *ops;
30 struct request_queue *q;
31 enum rq_qos_id id;
32 struct rq_qos *next;
33#ifdef CONFIG_BLK_DEBUG_FS
34 struct dentry *debugfs_dir;
35#endif
36};
37
38struct rq_qos_ops {
39 void (*throttle)(struct rq_qos *, struct bio *);
40 void (*track)(struct rq_qos *, struct request *, struct bio *);
41 void (*merge)(struct rq_qos *, struct request *, struct bio *);
42 void (*issue)(struct rq_qos *, struct request *);
43 void (*requeue)(struct rq_qos *, struct request *);
44 void (*done)(struct rq_qos *, struct request *);
45 void (*done_bio)(struct rq_qos *, struct bio *);
46 void (*cleanup)(struct rq_qos *, struct bio *);
47 void (*queue_depth_changed)(struct rq_qos *);
48 void (*exit)(struct rq_qos *);
49 const struct blk_mq_debugfs_attr *debugfs_attrs;
50};
51
52struct rq_depth {
53 unsigned int max_depth;
54
55 int scale_step;
56 bool scaled_max;
57
58 unsigned int queue_depth;
59 unsigned int default_depth;
60};
61
62static inline struct rq_qos *rq_qos_id(struct request_queue *q,
63 enum rq_qos_id id)
64{
65 struct rq_qos *rqos;
66 for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
67 if (rqos->id == id)
68 break;
69 }
70 return rqos;
71}
72
73static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
74{
75 return rq_qos_id(q, RQ_QOS_WBT);
76}
77
78static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
79{
80 return rq_qos_id(q, RQ_QOS_LATENCY);
81}
82
83static inline void rq_wait_init(struct rq_wait *rq_wait)
84{
85 atomic_set(&rq_wait->inflight, 0);
86 init_waitqueue_head(&rq_wait->wait);
87}
88
89static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
90{
91 /*
92 * No IO can be in-flight when adding rqos, so freeze queue, which
93 * is fine since we only support rq_qos for blk-mq queue.
94 *
95 * Reuse ->queue_lock for protecting against other concurrent
96 * rq_qos adding/deleting
97 */
98 blk_mq_freeze_queue(q);
99
100 spin_lock_irq(&q->queue_lock);
101 rqos->next = q->rq_qos;
102 q->rq_qos = rqos;
103 spin_unlock_irq(&q->queue_lock);
104
105 blk_mq_unfreeze_queue(q);
106
107 if (rqos->ops->debugfs_attrs)
108 blk_mq_debugfs_register_rqos(rqos);
109}
110
111static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
112{
113 struct rq_qos **cur;
114
115 /*
116 * See comment in rq_qos_add() about freezing queue & using
117 * ->queue_lock.
118 */
119 blk_mq_freeze_queue(q);
120
121 spin_lock_irq(&q->queue_lock);
122 for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
123 if (*cur == rqos) {
124 *cur = rqos->next;
125 break;
126 }
127 }
128 spin_unlock_irq(&q->queue_lock);
129
130 blk_mq_unfreeze_queue(q);
131
132 blk_mq_debugfs_unregister_rqos(rqos);
133}
134
135typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
136typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
137
138void rq_qos_wait(struct rq_wait *rqw, void *private_data,
139 acquire_inflight_cb_t *acquire_inflight_cb,
140 cleanup_cb_t *cleanup_cb);
141bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
142bool rq_depth_scale_up(struct rq_depth *rqd);
143bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
144bool rq_depth_calc_max_depth(struct rq_depth *rqd);
145
146void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
147void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
148void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
149void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
150void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
151void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
152void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
153void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
154void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
155
156static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
157{
158 if (q->rq_qos)
159 __rq_qos_cleanup(q->rq_qos, bio);
160}
161
162static inline void rq_qos_done(struct request_queue *q, struct request *rq)
163{
164 if (q->rq_qos)
165 __rq_qos_done(q->rq_qos, rq);
166}
167
168static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
169{
170 if (q->rq_qos)
171 __rq_qos_issue(q->rq_qos, rq);
172}
173
174static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
175{
176 if (q->rq_qos)
177 __rq_qos_requeue(q->rq_qos, rq);
178}
179
180static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio)
181{
182 if (q->rq_qos)
183 __rq_qos_done_bio(q->rq_qos, bio);
184}
185
186static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
187{
188 /*
189 * BIO_TRACKED lets controllers know that a bio went through the
190 * normal rq_qos path.
191 */
192 if (q->rq_qos) {
193 bio_set_flag(bio, BIO_TRACKED);
194 __rq_qos_throttle(q->rq_qos, bio);
195 }
196}
197
198static inline void rq_qos_track(struct request_queue *q, struct request *rq,
199 struct bio *bio)
200{
201 if (q->rq_qos)
202 __rq_qos_track(q->rq_qos, rq, bio);
203}
204
205static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
206 struct bio *bio)
207{
208 if (q->rq_qos)
209 __rq_qos_merge(q->rq_qos, rq, bio);
210}
211
212static inline void rq_qos_queue_depth_changed(struct request_queue *q)
213{
214 if (q->rq_qos)
215 __rq_qos_queue_depth_changed(q->rq_qos);
216}
217
218void rq_qos_exit(struct request_queue *);
219
220#endif