1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  BSD Process Accounting for Linux - Definitions
4  *
5  *  Author: Marco van Wieringen (mvw@planets.elm.net)
6  *
7  *  This header file contains the definitions needed to implement
8  *  BSD-style process accounting. The kernel accounting code and all
9  *  user-level programs that try to do something useful with the
10  *  process accounting log must include this file.
11  *
12  *  Copyright (C) 1995 - 1997 Marco van Wieringen - ELM Consultancy B.V.
13  *
14  */
15 #ifndef _LINUX_ACCT_H
16 #define _LINUX_ACCT_H
17 
18 #include <uapi/linux/acct.h>
19 
20 
21 
22 #ifdef CONFIG_BSD_PROCESS_ACCT
23 struct pid_namespace;
24 extern void acct_collect(long exitcode, int group_dead);
25 extern void acct_process(void);
26 extern void acct_exit_ns(struct pid_namespace *);
27 #else
28 #define acct_collect(x,y)	do { } while (0)
29 #define acct_process()		do { } while (0)
30 #define acct_exit_ns(ns)	do { } while (0)
31 #endif
32 
33 /*
34  * ACCT_VERSION numbers as yet defined:
35  * 0: old format (until 2.6.7) with 16 bit uid/gid
36  * 1: extended variant (binary compatible on M68K)
37  * 2: extended variant (binary compatible on everything except M68K)
38  * 3: new binary incompatible format (64 bytes)
39  * 4: new binary incompatible format (128 bytes)
40  * 5: new binary incompatible format (128 bytes, second half)
41  *
42  */
43 
44 #undef ACCT_VERSION
45 #undef AHZ
46 
47 #ifdef CONFIG_BSD_PROCESS_ACCT_V3
48 #define ACCT_VERSION	3
49 #define AHZ		100
50 typedef struct acct_v3 acct_t;
51 #else
52 #ifdef CONFIG_M68K
53 #define ACCT_VERSION	1
54 #else
55 #define ACCT_VERSION	2
56 #endif
57 #define AHZ		(USER_HZ)
58 typedef struct acct acct_t;
59 #endif
60 
61 #include <linux/jiffies.h>
62 /*
63  * Yet another set of HZ to *HZ helper functions.
64  * See <linux/jiffies.h> for the original.
65  */
66 
jiffies_to_AHZ(unsigned long x)67 static inline u32 jiffies_to_AHZ(unsigned long x)
68 {
69 #if (TICK_NSEC % (NSEC_PER_SEC / AHZ)) == 0
70 # if HZ < AHZ
71 	return x * (AHZ / HZ);
72 # else
73 	return x / (HZ / AHZ);
74 # endif
75 #else
76         u64 tmp = (u64)x * TICK_NSEC;
77         do_div(tmp, (NSEC_PER_SEC / AHZ));
78         return (long)tmp;
79 #endif
80 }
81 
nsec_to_AHZ(u64 x)82 static inline u64 nsec_to_AHZ(u64 x)
83 {
84 #if (NSEC_PER_SEC % AHZ) == 0
85 	do_div(x, (NSEC_PER_SEC / AHZ));
86 #elif (AHZ % 512) == 0
87 	x *= AHZ/512;
88 	do_div(x, (NSEC_PER_SEC / 512));
89 #else
90 	/*
91          * max relative error 5.7e-8 (1.8s per year) for AHZ <= 1024,
92          * overflow after 64.99 years.
93          * exact for AHZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
94          */
95 	x *= 9;
96 	do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (AHZ/2))
97 	                          / AHZ));
98 #endif
99 	return x;
100 }
101 
102 #endif	/* _LINUX_ACCT_H */
103