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 | |