1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* delayacct.h - per-task delay accounting 3 * 4 * Copyright (C) Shailabh Nagar, IBM Corp. 2006 5 */ 6 7#ifndef _LINUX_DELAYACCT_H 8#define _LINUX_DELAYACCT_H 9 10#include <uapi/linux/taskstats.h> 11 12/* 13 * Per-task flags relevant to delay accounting 14 * maintained privately to avoid exhausting similar flags in sched.h:PF_* 15 * Used to set current->delays->flags 16 */ 17#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */ 18#define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */ 19 20#ifdef CONFIG_TASK_DELAY_ACCT 21struct task_delay_info { 22 raw_spinlock_t lock; 23 unsigned int flags; /* Private per-task flags */ 24 25 /* For each stat XXX, add following, aligned appropriately 26 * 27 * struct timespec XXX_start, XXX_end; 28 * u64 XXX_delay; 29 * u32 XXX_count; 30 * 31 * Atomicity of updates to XXX_delay, XXX_count protected by 32 * single lock above (split into XXX_lock if contention is an issue). 33 */ 34 35 /* 36 * XXX_count is incremented on every XXX operation, the delay 37 * associated with the operation is added to XXX_delay. 38 * XXX_delay contains the accumulated delay time in nanoseconds. 39 */ 40 u64 blkio_start; /* Shared by blkio, swapin */ 41 u64 blkio_delay; /* wait for sync block io completion */ 42 u64 swapin_delay; /* wait for swapin block io completion */ 43 u32 blkio_count; /* total count of the number of sync block */ 44 /* io operations performed */ 45 u32 swapin_count; /* total count of the number of swapin block */ 46 /* io operations performed */ 47 48 u64 freepages_start; 49 u64 freepages_delay; /* wait for memory reclaim */ 50 51 u64 thrashing_start; 52 u64 thrashing_delay; /* wait for thrashing page */ 53 54 u32 freepages_count; /* total count of memory reclaim */ 55 u32 thrashing_count; /* total count of thrash waits */ 56}; 57#endif 58 59#include <linux/sched.h> 60#include <linux/slab.h> 61 62#ifdef CONFIG_TASK_DELAY_ACCT 63extern int delayacct_on; /* Delay accounting turned on/off */ 64extern struct kmem_cache *delayacct_cache; 65extern void delayacct_init(void); 66extern void __delayacct_tsk_init(struct task_struct *); 67extern void __delayacct_tsk_exit(struct task_struct *); 68extern void __delayacct_blkio_start(void); 69extern void __delayacct_blkio_end(struct task_struct *); 70extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); 71extern __u64 __delayacct_blkio_ticks(struct task_struct *); 72extern void __delayacct_freepages_start(void); 73extern void __delayacct_freepages_end(void); 74extern void __delayacct_thrashing_start(void); 75extern void __delayacct_thrashing_end(void); 76 77static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 78{ 79 if (p->delays) 80 return (p->delays->flags & DELAYACCT_PF_BLKIO); 81 else 82 return 0; 83} 84 85static inline void delayacct_set_flag(int flag) 86{ 87 if (current->delays) 88 current->delays->flags |= flag; 89} 90 91static inline void delayacct_clear_flag(int flag) 92{ 93 if (current->delays) 94 current->delays->flags &= ~flag; 95} 96 97static inline void delayacct_tsk_init(struct task_struct *tsk) 98{ 99 /* reinitialize in case parent's non-null pointer was dup'ed*/ 100 tsk->delays = NULL; 101 if (delayacct_on) 102 __delayacct_tsk_init(tsk); 103} 104 105/* Free tsk->delays. Called from bad fork and __put_task_struct 106 * where there's no risk of tsk->delays being accessed elsewhere 107 */ 108static inline void delayacct_tsk_free(struct task_struct *tsk) 109{ 110 if (tsk->delays) 111 kmem_cache_free(delayacct_cache, tsk->delays); 112 tsk->delays = NULL; 113} 114 115static inline void delayacct_blkio_start(void) 116{ 117 delayacct_set_flag(DELAYACCT_PF_BLKIO); 118 if (current->delays) 119 __delayacct_blkio_start(); 120} 121 122static inline void delayacct_blkio_end(struct task_struct *p) 123{ 124 if (p->delays) 125 __delayacct_blkio_end(p); 126 delayacct_clear_flag(DELAYACCT_PF_BLKIO); 127} 128 129static inline int delayacct_add_tsk(struct taskstats *d, 130 struct task_struct *tsk) 131{ 132 if (!delayacct_on || !tsk->delays) 133 return 0; 134 return __delayacct_add_tsk(d, tsk); 135} 136 137static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 138{ 139 if (tsk->delays) 140 return __delayacct_blkio_ticks(tsk); 141 return 0; 142} 143 144static inline void delayacct_freepages_start(void) 145{ 146 if (current->delays) 147 __delayacct_freepages_start(); 148} 149 150static inline void delayacct_freepages_end(void) 151{ 152 if (current->delays) 153 __delayacct_freepages_end(); 154} 155 156static inline void delayacct_thrashing_start(void) 157{ 158 if (current->delays) 159 __delayacct_thrashing_start(); 160} 161 162static inline void delayacct_thrashing_end(void) 163{ 164 if (current->delays) 165 __delayacct_thrashing_end(); 166} 167 168#else 169static inline void delayacct_set_flag(int flag) 170{} 171static inline void delayacct_clear_flag(int flag) 172{} 173static inline void delayacct_init(void) 174{} 175static inline void delayacct_tsk_init(struct task_struct *tsk) 176{} 177static inline void delayacct_tsk_free(struct task_struct *tsk) 178{} 179static inline void delayacct_blkio_start(void) 180{} 181static inline void delayacct_blkio_end(struct task_struct *p) 182{} 183static inline int delayacct_add_tsk(struct taskstats *d, 184 struct task_struct *tsk) 185{ return 0; } 186static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 187{ return 0; } 188static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 189{ return 0; } 190static inline void delayacct_freepages_start(void) 191{} 192static inline void delayacct_freepages_end(void) 193{} 194static inline void delayacct_thrashing_start(void) 195{} 196static inline void delayacct_thrashing_end(void) 197{} 198 199#endif /* CONFIG_TASK_DELAY_ACCT */ 200 201#endif 202