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 <linux/sched.h> 21#include <linux/slab.h> 22 23/* 24 * Per-task flags relevant to delay accounting 25 * maintained privately to avoid exhausting similar flags in sched.h:PF_* 26 * Used to set current->delays->flags 27 */ 28#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */ 29#define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */ 30 31#ifdef CONFIG_TASK_DELAY_ACCT 32 33extern int delayacct_on; /* Delay accounting turned on/off */ 34extern struct kmem_cache *delayacct_cache; 35extern void delayacct_init(void); 36extern void __delayacct_tsk_init(struct task_struct *); 37extern void __delayacct_tsk_exit(struct task_struct *); 38extern void __delayacct_blkio_start(void); 39extern void __delayacct_blkio_end(void); 40extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); 41extern __u64 __delayacct_blkio_ticks(struct task_struct *); 42extern void __delayacct_freepages_start(void); 43extern void __delayacct_freepages_end(void); 44 45static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 46{ 47 if (p->delays) 48 return (p->delays->flags & DELAYACCT_PF_BLKIO); 49 else 50 return 0; 51} 52 53static inline void delayacct_set_flag(int flag) 54{ 55 if (current->delays) 56 current->delays->flags |= flag; 57} 58 59static inline void delayacct_clear_flag(int flag) 60{ 61 if (current->delays) 62 current->delays->flags &= ~flag; 63} 64 65static inline void delayacct_tsk_init(struct task_struct *tsk) 66{ 67 /* reinitialize in case parent's non-null pointer was dup'ed*/ 68 tsk->delays = NULL; 69 if (delayacct_on) 70 __delayacct_tsk_init(tsk); 71} 72 73/* Free tsk->delays. Called from bad fork and __put_task_struct 74 * where there's no risk of tsk->delays being accessed elsewhere 75 */ 76static inline void delayacct_tsk_free(struct task_struct *tsk) 77{ 78 if (tsk->delays) 79 kmem_cache_free(delayacct_cache, tsk->delays); 80 tsk->delays = NULL; 81} 82 83static inline void delayacct_blkio_start(void) 84{ 85 delayacct_set_flag(DELAYACCT_PF_BLKIO); 86 if (current->delays) 87 __delayacct_blkio_start(); 88} 89 90static inline void delayacct_blkio_end(void) 91{ 92 if (current->delays) 93 __delayacct_blkio_end(); 94 delayacct_clear_flag(DELAYACCT_PF_BLKIO); 95} 96 97static inline int delayacct_add_tsk(struct taskstats *d, 98 struct task_struct *tsk) 99{ 100 if (!delayacct_on || !tsk->delays) 101 return 0; 102 return __delayacct_add_tsk(d, tsk); 103} 104 105static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 106{ 107 if (tsk->delays) 108 return __delayacct_blkio_ticks(tsk); 109 return 0; 110} 111 112static inline void delayacct_freepages_start(void) 113{ 114 if (current->delays) 115 __delayacct_freepages_start(); 116} 117 118static inline void delayacct_freepages_end(void) 119{ 120 if (current->delays) 121 __delayacct_freepages_end(); 122} 123 124#else 125static inline void delayacct_set_flag(int flag) 126{} 127static inline void delayacct_clear_flag(int flag) 128{} 129static inline void delayacct_init(void) 130{} 131static inline void delayacct_tsk_init(struct task_struct *tsk) 132{} 133static inline void delayacct_tsk_free(struct task_struct *tsk) 134{} 135static inline void delayacct_blkio_start(void) 136{} 137static inline void delayacct_blkio_end(void) 138{} 139static inline int delayacct_add_tsk(struct taskstats *d, 140 struct task_struct *tsk) 141{ return 0; } 142static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) 143{ return 0; } 144static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 145{ return 0; } 146static inline void delayacct_freepages_start(void) 147{} 148static inline void delayacct_freepages_end(void) 149{} 150 151#endif /* CONFIG_TASK_DELAY_ACCT */ 152 153#endif 154