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 62 #ifdef CONFIG_TASK_DELAY_ACCT 63 extern int delayacct_on; /* Delay accounting turned on/off */ 64 extern struct kmem_cache *delayacct_cache; 65 extern void delayacct_init(void); 66 extern void __delayacct_tsk_init(struct task_struct *); 67 extern void __delayacct_tsk_exit(struct task_struct *); 68 extern void __delayacct_blkio_start(void); 69 extern void __delayacct_blkio_end(struct task_struct *); 70 extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); 71 extern __u64 __delayacct_blkio_ticks(struct task_struct *); 72 extern void __delayacct_freepages_start(void); 73 extern void __delayacct_freepages_end(void); 74 extern void __delayacct_thrashing_start(void); 75 extern void __delayacct_thrashing_end(void); 76 77 static 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 85 static inline void delayacct_set_flag(int flag) 86 { 87 if (current->delays) 88 current->delays->flags |= flag; 89 } 90 91 static inline void delayacct_clear_flag(int flag) 92 { 93 if (current->delays) 94 current->delays->flags &= ~flag; 95 } 96 97 static 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 */ 108 static 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 } 114 115 static inline void delayacct_blkio_start(void) 116 { 117 delayacct_set_flag(DELAYACCT_PF_BLKIO); 118 if (current->delays) 119 __delayacct_blkio_start(); 120 } 121 122 static 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 } 128 129 static 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 } 136 137 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 138 { 139 if (tsk->delays) 140 return __delayacct_blkio_ticks(tsk); 141 return 0; 142 } 143 144 static inline void delayacct_freepages_start(void) 145 { 146 if (current->delays) 147 __delayacct_freepages_start(); 148 } 149 150 static inline void delayacct_freepages_end(void) 151 { 152 if (current->delays) 153 __delayacct_freepages_end(); 154 } 155 156 static inline void delayacct_thrashing_start(void) 157 { 158 if (current->delays) 159 __delayacct_thrashing_start(); 160 } 161 162 static inline void delayacct_thrashing_end(void) 163 { 164 if (current->delays) 165 __delayacct_thrashing_end(); 166 } 167 168 #else 169 static inline void delayacct_set_flag(int flag) 170 {} 171 static inline void delayacct_clear_flag(int flag) 172 {} 173 static inline void delayacct_init(void) 174 {} 175 static inline void delayacct_tsk_init(struct task_struct *tsk) 176 {} 177 static inline void delayacct_tsk_free(struct task_struct *tsk) 178 {} 179 static inline void delayacct_blkio_start(void) 180 {} 181 static inline void delayacct_blkio_end(struct task_struct *p) 182 {} 183 static inline int delayacct_add_tsk(struct taskstats *d, 184 struct task_struct *tsk) 185 { return 0; } 186 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 187 { return 0; } 188 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 189 { return 0; } 190 static inline void delayacct_freepages_start(void) 191 {} 192 static inline void delayacct_freepages_end(void) 193 {} 194 static inline void delayacct_thrashing_start(void) 195 {} 196 static inline void delayacct_thrashing_end(void) 197 {} 198 199 #endif /* CONFIG_TASK_DELAY_ACCT */ 200 201 #endif 202