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 int acct_parm[]; /* for sysctl */
25 extern void acct_collect(long exitcode, int group_dead);
26 extern void acct_process(void);
27 extern void acct_exit_ns(struct pid_namespace *);
28 #else
29 #define acct_collect(x,y)	do { } while (0)
30 #define acct_process()		do { } while (0)
31 #define acct_exit_ns(ns)	do { } while (0)
32 #endif
33 
34 /*
35  * ACCT_VERSION numbers as yet defined:
36  * 0: old format (until 2.6.7) with 16 bit uid/gid
37  * 1: extended variant (binary compatible on M68K)
38  * 2: extended variant (binary compatible on everything except M68K)
39  * 3: new binary incompatible format (64 bytes)
40  * 4: new binary incompatible format (128 bytes)
41  * 5: new binary incompatible format (128 bytes, second half)
42  *
43  */
44 
45 #undef ACCT_VERSION
46 #undef AHZ
47 
48 #ifdef CONFIG_BSD_PROCESS_ACCT_V3
49 #define ACCT_VERSION	3
50 #define AHZ		100
51 typedef struct acct_v3 acct_t;
52 #else
53 #ifdef CONFIG_M68K
54 #define ACCT_VERSION	1
55 #else
56 #define ACCT_VERSION	2
57 #endif
58 #define AHZ		(USER_HZ)
59 typedef struct acct acct_t;
60 #endif
61 
62 #include <linux/jiffies.h>
63 /*
64  * Yet another set of HZ to *HZ helper functions.
65  * See <linux/jiffies.h> for the original.
66  */
67 
jiffies_to_AHZ(unsigned long x)68 static inline u32 jiffies_to_AHZ(unsigned long x)
69 {
70 #if (TICK_NSEC % (NSEC_PER_SEC / AHZ)) == 0
71 # if HZ < AHZ
72 	return x * (AHZ / HZ);
73 # else
74 	return x / (HZ / AHZ);
75 # endif
76 #else
77         u64 tmp = (u64)x * TICK_NSEC;
78         do_div(tmp, (NSEC_PER_SEC / AHZ));
79         return (long)tmp;
80 #endif
81 }
82 
nsec_to_AHZ(u64 x)83 static inline u64 nsec_to_AHZ(u64 x)
84 {
85 #if (NSEC_PER_SEC % AHZ) == 0
86 	do_div(x, (NSEC_PER_SEC / AHZ));
87 #elif (AHZ % 512) == 0
88 	x *= AHZ/512;
89 	do_div(x, (NSEC_PER_SEC / 512));
90 #else
91 	/*
92          * max relative error 5.7e-8 (1.8s per year) for AHZ <= 1024,
93          * overflow after 64.99 years.
94          * exact for AHZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
95          */
96 	x *= 9;
97 	do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (AHZ/2))
98 	                          / AHZ));
99 #endif
100 	return x;
101 }
102 
103 #endif	/* _LINUX_ACCT_H */
104