include/linux/acct.h

   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 vfsmount;
  24 struct super_block;
  25 struct pacct_struct;
  26 struct pid_namespace;
  27 extern int acct_parm[]; /* for sysctl */
  28 extern void acct_collect(long exitcode, int group_dead);
  29 extern void acct_process(void);
  30 extern void acct_exit_ns(struct pid_namespace *);
  31 #else
  32 #define acct_collect(x,y)       do { } while (0)
  33 #define acct_process()          do { } while (0)
  34 #define acct_exit_ns(ns)        do { } while (0)
  35 #endif
  36
  37 /*
  38  * ACCT_VERSION numbers as yet defined:
  39  * 0: old format (until 2.6.7) with 16 bit uid/gid
  40  * 1: extended variant (binary compatible on M68K)
  41  * 2: extended variant (binary compatible on everything except M68K)
  42  * 3: new binary incompatible format (64 bytes)
  43  * 4: new binary incompatible format (128 bytes)
  44  * 5: new binary incompatible format (128 bytes, second half)
  45  *
  46  */
  47
  48 #undef ACCT_VERSION
  49 #undef AHZ
  50
  51 #ifdef CONFIG_BSD_PROCESS_ACCT_V3
  52 #define ACCT_VERSION    3
  53 #define AHZ             100
  54 typedef struct acct_v3 acct_t;
  55 #else
  56 #ifdef CONFIG_M68K
  57 #define ACCT_VERSION    1
  58 #else
  59 #define ACCT_VERSION    2
  60 #endif
  61 #define AHZ             (USER_HZ)
  62 typedef struct acct acct_t;
  63 #endif
  64
  65 #include <linux/jiffies.h>
  66 /*
  67  * Yet another set of HZ to *HZ helper functions.
  68  * See <linux/jiffies.h> for the original.
  69  */
  70
  71 static inline u32 jiffies_to_AHZ(unsigned long x)
  72 {
  73 #if (TICK_NSEC % (NSEC_PER_SEC / AHZ)) == 0
  74 # if HZ < AHZ
  75         return x * (AHZ / HZ);
  76 # else
  77         return x / (HZ / AHZ);
  78 # endif
  79 #else
  80         u64 tmp = (u64)x * TICK_NSEC;
  81         do_div(tmp, (NSEC_PER_SEC / AHZ));
  82         return (long)tmp;
  83 #endif
  84 }
  85
  86 static inline u64 nsec_to_AHZ(u64 x)
  87 {
  88 #if (NSEC_PER_SEC % AHZ) == 0
  89         do_div(x, (NSEC_PER_SEC / AHZ));
  90 #elif (AHZ % 512) == 0
  91         x *= AHZ/512;
  92         do_div(x, (NSEC_PER_SEC / 512));
  93 #else
  94         /*
  95          * max relative error 5.7e-8 (1.8s per year) for AHZ <= 1024,
  96          * overflow after 64.99 years.
  97          * exact for AHZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
  98          */
  99         x *= 9;
 100         do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (AHZ/2))
 101                                   / AHZ));
 102 #endif
 103         return x;
 104 }
 105
 106 #endif  /* _LINUX_ACCT_H */