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 WBT_STATE_OFF_DEFAULT 38 }; 39 40 struct rq_wb { 41 /* 42 * Settings that govern how we throttle 43 */ 44 unsigned int wb_background; /* background writeback */ 45 unsigned int wb_normal; /* normal writeback */ 46 47 short enable_state; /* WBT_STATE_* */ 48 49 /* 50 * Number of consecutive periods where we don't have enough 51 * information to make a firm scale up/down decision. 52 */ 53 unsigned int unknown_cnt; 54 55 u64 win_nsec; /* default window size */ 56 u64 cur_win_nsec; /* current window size */ 57 58 struct blk_stat_callback *cb; 59 60 u64 sync_issue; 61 void *sync_cookie; 62 63 unsigned int wc; 64 65 unsigned long last_issue; /* last non-throttled issue */ 66 unsigned long last_comp; /* last non-throttled comp */ 67 unsigned long min_lat_nsec; 68 struct rq_qos rqos; 69 struct rq_wait rq_wait[WBT_NUM_RWQ]; 70 struct rq_depth rq_depth; 71 }; 72 73 static inline struct rq_wb *RQWB(struct rq_qos *rqos) 74 { 75 return container_of(rqos, struct rq_wb, rqos); 76 } 77 78 static inline unsigned int wbt_inflight(struct rq_wb *rwb) 79 { 80 unsigned int i, ret = 0; 81 82 for (i = 0; i < WBT_NUM_RWQ; i++) 83 ret += atomic_read(&rwb->rq_wait[i].inflight); 84 85 return ret; 86 } 87 88 89 #ifdef CONFIG_BLK_WBT 90 91 int wbt_init(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_write_cache(struct request_queue *, bool); 99 100 u64 wbt_default_latency_nsec(struct request_queue *); 101 102 #else 103 104 static inline void wbt_track(struct request *rq, enum wbt_flags flags) 105 { 106 } 107 static inline int wbt_init(struct request_queue *q) 108 { 109 return -EINVAL; 110 } 111 static inline void wbt_disable_default(struct request_queue *q) 112 { 113 } 114 static inline void wbt_enable_default(struct request_queue *q) 115 { 116 } 117 static inline void wbt_set_write_cache(struct request_queue *q, bool wc) 118 { 119 } 120 static inline u64 wbt_get_min_lat(struct request_queue *q) 121 { 122 return 0; 123 } 124 static inline void wbt_set_min_lat(struct request_queue *q, u64 val) 125 { 126 } 127 static inline u64 wbt_default_latency_nsec(struct request_queue *q) 128 { 129 return 0; 130 } 131 132 #endif /* CONFIG_BLK_WBT */ 133 134 #endif 135