xref: /linux-6.15/include/linux/delayacct.h (revision bbc90bc1)
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 #ifdef CONFIG_TASK_DELAY_ACCT
13 struct task_delay_info {
14 	raw_spinlock_t	lock;
15 
16 	/* For each stat XXX, add following, aligned appropriately
17 	 *
18 	 * struct timespec XXX_start, XXX_end;
19 	 * u64 XXX_delay;
20 	 * u32 XXX_count;
21 	 *
22 	 * Atomicity of updates to XXX_delay, XXX_count protected by
23 	 * single lock above (split into XXX_lock if contention is an issue).
24 	 */
25 
26 	/*
27 	 * XXX_count is incremented on every XXX operation, the delay
28 	 * associated with the operation is added to XXX_delay.
29 	 * XXX_delay contains the accumulated delay time in nanoseconds.
30 	 */
31 	u64 blkio_start;
32 	u64 blkio_delay;	/* wait for sync block io completion */
33 	u64 swapin_start;
34 	u64 swapin_delay;	/* wait for swapin */
35 	u32 blkio_count;	/* total count of the number of sync block */
36 				/* io operations performed */
37 	u32 swapin_count;	/* total count of swapin */
38 
39 	u64 freepages_start;
40 	u64 freepages_delay;	/* wait for memory reclaim */
41 
42 	u64 thrashing_start;
43 	u64 thrashing_delay;	/* wait for thrashing page */
44 
45 	u64 compact_start;
46 	u64 compact_delay;	/* wait for memory compact */
47 
48 	u32 freepages_count;	/* total count of memory reclaim */
49 	u32 thrashing_count;	/* total count of thrash waits */
50 	u32 compact_count;	/* total count of memory compact */
51 };
52 #endif
53 
54 #include <linux/sched.h>
55 #include <linux/slab.h>
56 #include <linux/jump_label.h>
57 
58 #ifdef CONFIG_TASK_DELAY_ACCT
59 DECLARE_STATIC_KEY_FALSE(delayacct_key);
60 extern int delayacct_on;	/* Delay accounting turned on/off */
61 extern struct kmem_cache *delayacct_cache;
62 extern void delayacct_init(void);
63 
64 extern int sysctl_delayacct(struct ctl_table *table, int write, void *buffer,
65 			    size_t *lenp, loff_t *ppos);
66 
67 extern void __delayacct_tsk_init(struct task_struct *);
68 extern void __delayacct_tsk_exit(struct task_struct *);
69 extern void __delayacct_blkio_start(void);
70 extern void __delayacct_blkio_end(struct task_struct *);
71 extern int delayacct_add_tsk(struct taskstats *, struct task_struct *);
72 extern __u64 __delayacct_blkio_ticks(struct task_struct *);
73 extern void __delayacct_freepages_start(void);
74 extern void __delayacct_freepages_end(void);
75 extern void __delayacct_thrashing_start(void);
76 extern void __delayacct_thrashing_end(void);
77 extern void __delayacct_swapin_start(void);
78 extern void __delayacct_swapin_end(void);
79 extern void __delayacct_compact_start(void);
80 extern void __delayacct_compact_end(void);
81 
82 static inline void delayacct_tsk_init(struct task_struct *tsk)
83 {
84 	/* reinitialize in case parent's non-null pointer was dup'ed*/
85 	tsk->delays = NULL;
86 	if (delayacct_on)
87 		__delayacct_tsk_init(tsk);
88 }
89 
90 /* Free tsk->delays. Called from bad fork and __put_task_struct
91  * where there's no risk of tsk->delays being accessed elsewhere
92  */
93 static inline void delayacct_tsk_free(struct task_struct *tsk)
94 {
95 	if (tsk->delays)
96 		kmem_cache_free(delayacct_cache, tsk->delays);
97 	tsk->delays = NULL;
98 }
99 
100 static inline void delayacct_blkio_start(void)
101 {
102 	if (!static_branch_unlikely(&delayacct_key))
103 		return;
104 
105 	if (current->delays)
106 		__delayacct_blkio_start();
107 }
108 
109 static inline void delayacct_blkio_end(struct task_struct *p)
110 {
111 	if (!static_branch_unlikely(&delayacct_key))
112 		return;
113 
114 	if (p->delays)
115 		__delayacct_blkio_end(p);
116 }
117 
118 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
119 {
120 	if (tsk->delays)
121 		return __delayacct_blkio_ticks(tsk);
122 	return 0;
123 }
124 
125 static inline void delayacct_freepages_start(void)
126 {
127 	if (!static_branch_unlikely(&delayacct_key))
128 		return;
129 
130 	if (current->delays)
131 		__delayacct_freepages_start();
132 }
133 
134 static inline void delayacct_freepages_end(void)
135 {
136 	if (!static_branch_unlikely(&delayacct_key))
137 		return;
138 
139 	if (current->delays)
140 		__delayacct_freepages_end();
141 }
142 
143 static inline void delayacct_thrashing_start(void)
144 {
145 	if (!static_branch_unlikely(&delayacct_key))
146 		return;
147 
148 	if (current->delays)
149 		__delayacct_thrashing_start();
150 }
151 
152 static inline void delayacct_thrashing_end(void)
153 {
154 	if (!static_branch_unlikely(&delayacct_key))
155 		return;
156 
157 	if (current->delays)
158 		__delayacct_thrashing_end();
159 }
160 
161 static inline void delayacct_swapin_start(void)
162 {
163 	if (!static_branch_unlikely(&delayacct_key))
164 		return;
165 
166 	if (current->delays)
167 		__delayacct_swapin_start();
168 }
169 
170 static inline void delayacct_swapin_end(void)
171 {
172 	if (!static_branch_unlikely(&delayacct_key))
173 		return;
174 
175 	if (current->delays)
176 		__delayacct_swapin_end();
177 }
178 
179 static inline void delayacct_compact_start(void)
180 {
181 	if (!static_branch_unlikely(&delayacct_key))
182 		return;
183 
184 	if (current->delays)
185 		__delayacct_compact_start();
186 }
187 
188 static inline void delayacct_compact_end(void)
189 {
190 	if (!static_branch_unlikely(&delayacct_key))
191 		return;
192 
193 	if (current->delays)
194 		__delayacct_compact_end();
195 }
196 
197 #else
198 static inline void delayacct_init(void)
199 {}
200 static inline void delayacct_tsk_init(struct task_struct *tsk)
201 {}
202 static inline void delayacct_tsk_free(struct task_struct *tsk)
203 {}
204 static inline void delayacct_blkio_start(void)
205 {}
206 static inline void delayacct_blkio_end(struct task_struct *p)
207 {}
208 static inline int delayacct_add_tsk(struct taskstats *d,
209 					struct task_struct *tsk)
210 { return 0; }
211 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
212 { return 0; }
213 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
214 { return 0; }
215 static inline void delayacct_freepages_start(void)
216 {}
217 static inline void delayacct_freepages_end(void)
218 {}
219 static inline void delayacct_thrashing_start(void)
220 {}
221 static inline void delayacct_thrashing_end(void)
222 {}
223 static inline void delayacct_swapin_start(void)
224 {}
225 static inline void delayacct_swapin_end(void)
226 {}
227 static inline void delayacct_compact_start(void)
228 {}
229 static inline void delayacct_compact_end(void)
230 {}
231 
232 #endif /* CONFIG_TASK_DELAY_ACCT */
233 
234 #endif
235