/* SPDX-License-Identifier: GPL-2.0 */ #ifndef WB_THROTTLE_H #define WB_THROTTLE_H #include <linux/kernel.h> #include <linux/atomic.h> #include <linux/wait.h> #include <linux/timer.h> #include <linux/ktime.h> #include "blk-stat.h" #include "blk-rq-qos.h" enum wbt_flags { WBT_TRACKED = 1, /* write, tracked for throttling */ WBT_READ = 2, /* read */ WBT_KSWAPD = 4, /* write, from kswapd */ WBT_DISCARD = 8, /* discard */ WBT_NR_BITS = 4, /* number of bits */ }; enum { WBT_RWQ_BG = 0, WBT_RWQ_KSWAPD, WBT_RWQ_DISCARD, WBT_NUM_RWQ, }; /* * Enable states. Either off, or on by default (done at init time), * or on through manual setup in sysfs. */ enum { WBT_STATE_ON_DEFAULT = 1, WBT_STATE_ON_MANUAL = 2, }; struct rq_wb { /* * Settings that govern how we throttle */ unsigned int wb_background; /* background writeback */ unsigned int wb_normal; /* normal writeback */ short enable_state; /* WBT_STATE_* */ /* * Number of consecutive periods where we don't have enough * information to make a firm scale up/down decision. */ unsigned int unknown_cnt; u64 win_nsec; /* default window size */ u64 cur_win_nsec; /* current window size */ struct blk_stat_callback *cb; u64 sync_issue; void *sync_cookie; unsigned int wc; unsigned long last_issue; /* last non-throttled issue */ unsigned long last_comp; /* last non-throttled comp */ unsigned long min_lat_nsec; struct rq_qos rqos; struct rq_wait rq_wait[WBT_NUM_RWQ]; struct rq_depth rq_depth; }; static inline struct rq_wb *RQWB(struct rq_qos *rqos) { return container_of(rqos, struct rq_wb, rqos); } static inline unsigned int wbt_inflight(struct rq_wb *rwb) { unsigned int i, ret = 0; for (i = 0; i < WBT_NUM_RWQ; i++) ret += atomic_read(&rwb->rq_wait[i].inflight); return ret; } #ifdef CONFIG_BLK_WBT int wbt_init(struct request_queue *); void wbt_disable_default(struct request_queue *); void wbt_enable_default(struct request_queue *); u64 wbt_get_min_lat(struct request_queue *q); void wbt_set_min_lat(struct request_queue *q, u64 val); void wbt_set_write_cache(struct request_queue *, bool); u64 wbt_default_latency_nsec(struct request_queue *); #else static inline void wbt_track(struct request *rq, enum wbt_flags flags) { } static inline int wbt_init(struct request_queue *q) { return -EINVAL; } static inline void wbt_disable_default(struct request_queue *q) { } static inline void wbt_enable_default(struct request_queue *q) { } static inline void wbt_set_write_cache(struct request_queue *q, bool wc) { } static inline u64 wbt_get_min_lat(struct request_queue *q) { return 0; } static inline void wbt_set_min_lat(struct request_queue *q, u64 val) { } static inline u64 wbt_default_latency_nsec(struct request_queue *q) { return 0; } #endif /* CONFIG_BLK_WBT */ #endif