LXR linux/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
  23struct pid_namespace;
  24extern int acct_parm[]; /* for sysctl */
  25extern void acct_collect(long exitcode, int group_dead);
  26extern void acct_process(void);
  27extern 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
  51typedef 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)
  59typedef 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
  68static 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
  83static 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