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 21 struct 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 #include <linux/jump_label.h> 62 63 #ifdef CONFIG_TASK_DELAY_ACCT 64 DECLARE_STATIC_KEY_FALSE(delayacct_key); 65 extern int delayacct_on; /* Delay accounting turned on/off */ 66 extern struct kmem_cache *delayacct_cache; 67 extern void delayacct_init(void); 68 69 extern int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, 70 size_t *lenp, loff_t *ppos); 71 72 extern void __delayacct_tsk_init(struct task_struct *); 73 extern void __delayacct_tsk_exit(struct task_struct *); 74 extern void __delayacct_blkio_start(void); 75 extern void __delayacct_blkio_end(struct task_struct *); 76 extern int delayacct_add_tsk(struct taskstats *, struct task_struct *); 77 extern __u64 __delayacct_blkio_ticks(struct task_struct *); 78 extern void __delayacct_freepages_start(void); 79 extern void __delayacct_freepages_end(void); 80 extern void __delayacct_thrashing_start(void); 81 extern void __delayacct_thrashing_end(void); 82 83 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 84 { 85 if (p->delays) 86 return (p->delays->flags & DELAYACCT_PF_BLKIO); 87 else 88 return 0; 89 } 90 91 static inline void delayacct_set_flag(struct task_struct *p, int flag) 92 { 93 if (p->delays) 94 p->delays->flags |= flag; 95 } 96 97 static inline void delayacct_clear_flag(struct task_struct *p, int flag) 98 { 99 if (p->delays) 100 p->delays->flags &= ~flag; 101 } 102 103 static inline void delayacct_tsk_init(struct task_struct *tsk) 104 { 105 /* reinitialize in case parent's non-null pointer was dup'ed*/ 106 tsk->delays = NULL; 107 if (delayacct_on) 108 __delayacct_tsk_init(tsk); 109 } 110 111 /* Free tsk->delays. Called from bad fork and __put_task_struct 112 * where there's no risk of tsk->delays being accessed elsewhere 113 */ 114 static inline void delayacct_tsk_free(struct task_struct *tsk) 115 { 116 if (tsk->delays) 117 kmem_cache_free(delayacct_cache, tsk->delays); 118 tsk->delays = NULL; 119 } 120 121 static inline void delayacct_blkio_start(void) 122 { 123 if (!static_branch_unlikely(&delayacct_key)) 124 return; 125 126 delayacct_set_flag(current, DELAYACCT_PF_BLKIO); 127 if (current->delays) 128 __delayacct_blkio_start(); 129 } 130 131 static inline void delayacct_blkio_end(struct task_struct *p) 132 { 133 if (!static_branch_unlikely(&delayacct_key)) 134 return; 135 136 if (p->delays) 137 __delayacct_blkio_end(p); 138 delayacct_clear_flag(p, DELAYACCT_PF_BLKIO); 139 } 140 141 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 142 { 143 if (tsk->delays) 144 return __delayacct_blkio_ticks(tsk); 145 return 0; 146 } 147 148 static inline void delayacct_freepages_start(void) 149 { 150 if (current->delays) 151 __delayacct_freepages_start(); 152 } 153 154 static inline void delayacct_freepages_end(void) 155 { 156 if (current->delays) 157 __delayacct_freepages_end(); 158 } 159 160 static inline void delayacct_thrashing_start(void) 161 { 162 if (current->delays) 163 __delayacct_thrashing_start(); 164 } 165 166 static inline void delayacct_thrashing_end(void) 167 { 168 if (current->delays) 169 __delayacct_thrashing_end(); 170 } 171 172 #else 173 static inline void delayacct_set_flag(struct task_struct *p, int flag) 174 {} 175 static inline void delayacct_clear_flag(struct task_struct *p, int flag) 176 {} 177 static inline void delayacct_init(void) 178 {} 179 static inline void delayacct_tsk_init(struct task_struct *tsk) 180 {} 181 static inline void delayacct_tsk_free(struct task_struct *tsk) 182 {} 183 static inline void delayacct_blkio_start(void) 184 {} 185 static inline void delayacct_blkio_end(struct task_struct *p) 186 {} 187 static inline int delayacct_add_tsk(struct taskstats *d, 188 struct task_struct *tsk) 189 { return 0; } 190 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 191 { return 0; } 192 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 193 { return 0; } 194 static inline void delayacct_freepages_start(void) 195 {} 196 static inline void delayacct_freepages_end(void) 197 {} 198 static inline void delayacct_thrashing_start(void) 199 {} 200 static inline void delayacct_thrashing_end(void) 201 {} 202 203 #endif /* CONFIG_TASK_DELAY_ACCT */ 204 205 #endif 206