1 /* delayacct.h - per-task delay accounting 2 * 3 * Copyright (C) Shailabh Nagar, IBM Corp. 2006 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 13 * the GNU General Public License for more details. 14 * 15 */ 16 17 #ifndef _LINUX_DELAYACCT_H 18 #define _LINUX_DELAYACCT_H 19 20 #include <uapi/linux/taskstats.h> 21 22 /* 23 * Per-task flags relevant to delay accounting 24 * maintained privately to avoid exhausting similar flags in sched.h:PF_* 25 * Used to set current->delays->flags 26 */ 27 #define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */ 28 #define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */ 29 30 #ifdef CONFIG_TASK_DELAY_ACCT 31 struct task_delay_info { 32 raw_spinlock_t lock; 33 unsigned int flags; /* Private per-task flags */ 34 35 /* For each stat XXX, add following, aligned appropriately 36 * 37 * struct timespec XXX_start, XXX_end; 38 * u64 XXX_delay; 39 * u32 XXX_count; 40 * 41 * Atomicity of updates to XXX_delay, XXX_count protected by 42 * single lock above (split into XXX_lock if contention is an issue). 43 */ 44 45 /* 46 * XXX_count is incremented on every XXX operation, the delay 47 * associated with the operation is added to XXX_delay. 48 * XXX_delay contains the accumulated delay time in nanoseconds. 49 */ 50 u64 blkio_start; /* Shared by blkio, swapin */ 51 u64 blkio_delay; /* wait for sync block io completion */ 52 u64 swapin_delay; /* wait for swapin block io completion */ 53 u32 blkio_count; /* total count of the number of sync block */ 54 /* io operations performed */ 55 u32 swapin_count; /* total count of the number of swapin block */ 56 /* io operations performed */ 57 58 u64 freepages_start; 59 u64 freepages_delay; /* wait for memory reclaim */ 60 61 u64 thrashing_start; 62 u64 thrashing_delay; /* wait for thrashing page */ 63 64 u32 freepages_count; /* total count of memory reclaim */ 65 u32 thrashing_count; /* total count of thrash waits */ 66 }; 67 #endif 68 69 #include <linux/sched.h> 70 #include <linux/slab.h> 71 72 #ifdef CONFIG_TASK_DELAY_ACCT 73 extern int delayacct_on; /* Delay accounting turned on/off */ 74 extern struct kmem_cache *delayacct_cache; 75 extern void delayacct_init(void); 76 extern void __delayacct_tsk_init(struct task_struct *); 77 extern void __delayacct_tsk_exit(struct task_struct *); 78 extern void __delayacct_blkio_start(void); 79 extern void __delayacct_blkio_end(struct task_struct *); 80 extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); 81 extern __u64 __delayacct_blkio_ticks(struct task_struct *); 82 extern void __delayacct_freepages_start(void); 83 extern void __delayacct_freepages_end(void); 84 extern void __delayacct_thrashing_start(void); 85 extern void __delayacct_thrashing_end(void); 86 87 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 88 { 89 if (p->delays) 90 return (p->delays->flags & DELAYACCT_PF_BLKIO); 91 else 92 return 0; 93 } 94 95 static inline void delayacct_set_flag(int flag) 96 { 97 if (current->delays) 98 current->delays->flags |= flag; 99 } 100 101 static inline void delayacct_clear_flag(int flag) 102 { 103 if (current->delays) 104 current->delays->flags &= ~flag; 105 } 106 107 static inline void delayacct_tsk_init(struct task_struct *tsk) 108 { 109 /* reinitialize in case parent's non-null pointer was dup'ed*/ 110 tsk->delays = NULL; 111 if (delayacct_on) 112 __delayacct_tsk_init(tsk); 113 } 114 115 /* Free tsk->delays. Called from bad fork and __put_task_struct 116 * where there's no risk of tsk->delays being accessed elsewhere 117 */ 118 static inline void delayacct_tsk_free(struct task_struct *tsk) 119 { 120 if (tsk->delays) 121 kmem_cache_free(delayacct_cache, tsk->delays); 122 tsk->delays = NULL; 123 } 124 125 static inline void delayacct_blkio_start(void) 126 { 127 delayacct_set_flag(DELAYACCT_PF_BLKIO); 128 if (current->delays) 129 __delayacct_blkio_start(); 130 } 131 132 static inline void delayacct_blkio_end(struct task_struct *p) 133 { 134 if (p->delays) 135 __delayacct_blkio_end(p); 136 delayacct_clear_flag(DELAYACCT_PF_BLKIO); 137 } 138 139 static inline int delayacct_add_tsk(struct taskstats *d, 140 struct task_struct *tsk) 141 { 142 if (!delayacct_on || !tsk->delays) 143 return 0; 144 return __delayacct_add_tsk(d, tsk); 145 } 146 147 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 148 { 149 if (tsk->delays) 150 return __delayacct_blkio_ticks(tsk); 151 return 0; 152 } 153 154 static inline void delayacct_freepages_start(void) 155 { 156 if (current->delays) 157 __delayacct_freepages_start(); 158 } 159 160 static inline void delayacct_freepages_end(void) 161 { 162 if (current->delays) 163 __delayacct_freepages_end(); 164 } 165 166 static inline void delayacct_thrashing_start(void) 167 { 168 if (current->delays) 169 __delayacct_thrashing_start(); 170 } 171 172 static inline void delayacct_thrashing_end(void) 173 { 174 if (current->delays) 175 __delayacct_thrashing_end(); 176 } 177 178 #else 179 static inline void delayacct_set_flag(int flag) 180 {} 181 static inline void delayacct_clear_flag(int flag) 182 {} 183 static inline void delayacct_init(void) 184 {} 185 static inline void delayacct_tsk_init(struct task_struct *tsk) 186 {} 187 static inline void delayacct_tsk_free(struct task_struct *tsk) 188 {} 189 static inline void delayacct_blkio_start(void) 190 {} 191 static inline void delayacct_blkio_end(struct task_struct *p) 192 {} 193 static inline int delayacct_add_tsk(struct taskstats *d, 194 struct task_struct *tsk) 195 { return 0; } 196 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 197 { return 0; } 198 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 199 { return 0; } 200 static inline void delayacct_freepages_start(void) 201 {} 202 static inline void delayacct_freepages_end(void) 203 {} 204 static inline void delayacct_thrashing_start(void) 205 {} 206 static inline void delayacct_thrashing_end(void) 207 {} 208 209 #endif /* CONFIG_TASK_DELAY_ACCT */ 210 211 #endif 212