1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef WB_THROTTLE_H |
3 | #define WB_THROTTLE_H |
4 | |
5 | #include <linux/kernel.h> |
6 | #include <linux/atomic.h> |
7 | #include <linux/wait.h> |
8 | #include <linux/timer.h> |
9 | #include <linux/ktime.h> |
10 | |
11 | #include "blk-stat.h" |
12 | #include "blk-rq-qos.h" |
13 | |
14 | enum wbt_flags { |
15 | WBT_TRACKED = 1, /* write, tracked for throttling */ |
16 | WBT_READ = 2, /* read */ |
17 | WBT_KSWAPD = 4, /* write, from kswapd */ |
18 | WBT_DISCARD = 8, /* discard */ |
19 | |
20 | WBT_NR_BITS = 4, /* number of bits */ |
21 | }; |
22 | |
23 | enum { |
24 | WBT_RWQ_BG = 0, |
25 | WBT_RWQ_KSWAPD, |
26 | WBT_RWQ_DISCARD, |
27 | WBT_NUM_RWQ, |
28 | }; |
29 | |
30 | /* |
31 | * Enable states. Either off, or on by default (done at init time), |
32 | * or on through manual setup in sysfs. |
33 | */ |
34 | enum { |
35 | WBT_STATE_ON_DEFAULT = 1, |
36 | WBT_STATE_ON_MANUAL = 2, |
37 | }; |
38 | |
39 | struct rq_wb { |
40 | /* |
41 | * Settings that govern how we throttle |
42 | */ |
43 | unsigned int wb_background; /* background writeback */ |
44 | unsigned int wb_normal; /* normal writeback */ |
45 | |
46 | short enable_state; /* WBT_STATE_* */ |
47 | |
48 | /* |
49 | * Number of consecutive periods where we don't have enough |
50 | * information to make a firm scale up/down decision. |
51 | */ |
52 | unsigned int unknown_cnt; |
53 | |
54 | u64 win_nsec; /* default window size */ |
55 | u64 cur_win_nsec; /* current window size */ |
56 | |
57 | struct blk_stat_callback *cb; |
58 | |
59 | u64 sync_issue; |
60 | void *sync_cookie; |
61 | |
62 | unsigned int wc; |
63 | |
64 | unsigned long last_issue; /* last non-throttled issue */ |
65 | unsigned long last_comp; /* last non-throttled comp */ |
66 | unsigned long min_lat_nsec; |
67 | struct rq_qos rqos; |
68 | struct rq_wait rq_wait[WBT_NUM_RWQ]; |
69 | struct rq_depth rq_depth; |
70 | }; |
71 | |
72 | static inline struct rq_wb *RQWB(struct rq_qos *rqos) |
73 | { |
74 | return container_of(rqos, struct rq_wb, rqos); |
75 | } |
76 | |
77 | static inline unsigned int wbt_inflight(struct rq_wb *rwb) |
78 | { |
79 | unsigned int i, ret = 0; |
80 | |
81 | for (i = 0; i < WBT_NUM_RWQ; i++) |
82 | ret += atomic_read(&rwb->rq_wait[i].inflight); |
83 | |
84 | return ret; |
85 | } |
86 | |
87 | |
88 | #ifdef CONFIG_BLK_WBT |
89 | |
90 | int wbt_init(struct request_queue *); |
91 | void wbt_update_limits(struct request_queue *); |
92 | void wbt_disable_default(struct request_queue *); |
93 | void wbt_enable_default(struct request_queue *); |
94 | |
95 | u64 wbt_get_min_lat(struct request_queue *q); |
96 | void wbt_set_min_lat(struct request_queue *q, u64 val); |
97 | |
98 | void wbt_set_queue_depth(struct request_queue *, unsigned int); |
99 | void wbt_set_write_cache(struct request_queue *, bool); |
100 | |
101 | u64 wbt_default_latency_nsec(struct request_queue *); |
102 | |
103 | #else |
104 | |
105 | static inline void wbt_track(struct request *rq, enum wbt_flags flags) |
106 | { |
107 | } |
108 | static inline int wbt_init(struct request_queue *q) |
109 | { |
110 | return -EINVAL; |
111 | } |
112 | static inline void wbt_update_limits(struct request_queue *q) |
113 | { |
114 | } |
115 | static inline void wbt_disable_default(struct request_queue *q) |
116 | { |
117 | } |
118 | static inline void wbt_enable_default(struct request_queue *q) |
119 | { |
120 | } |
121 | static inline void wbt_set_queue_depth(struct request_queue *q, unsigned int depth) |
122 | { |
123 | } |
124 | static inline void wbt_set_write_cache(struct request_queue *q, bool wc) |
125 | { |
126 | } |
127 | static inline u64 wbt_get_min_lat(struct request_queue *q) |
128 | { |
129 | return 0; |
130 | } |
131 | static inline void wbt_set_min_lat(struct request_queue *q, u64 val) |
132 | { |
133 | } |
134 | static inline u64 wbt_default_latency_nsec(struct request_queue *q) |
135 | { |
136 | return 0; |
137 | } |
138 | |
139 | #endif /* CONFIG_BLK_WBT */ |
140 | |
141 | #endif |
142 | |