LXR linux/include/linux/acct.h

   1/*
   2 *  BSD Process Accounting for Linux - Definitions
   3 *
   4 *  Author: Marco van Wieringen (mvw@planets.elm.net)
   5 *
   6 *  This header file contains the definitions needed to implement
   7 *  BSD-style process accounting. The kernel accounting code and all
   8 *  user-level programs that try to do something useful with the
   9 *  process accounting log must include this file.
  10 *
  11 *  Copyright (C) 1995 - 1997 Marco van Wieringen - ELM Consultancy B.V.
  12 *
  13 */
  14#ifndef _LINUX_ACCT_H
  15#define _LINUX_ACCT_H
  16
  17#include <uapi/linux/acct.h>
  18
  19
  20
  21#ifdef CONFIG_BSD_PROCESS_ACCT
  22struct vfsmount;
  23struct super_block;
  24struct pacct_struct;
  25struct pid_namespace;
  26extern int acct_parm[]; /* for sysctl */
  27extern void acct_collect(long exitcode, int group_dead);
  28extern void acct_process(void);
  29extern void acct_exit_ns(struct pid_namespace *);
  30#else
  31#define acct_collect(x,y)       do { } while (0)
  32#define acct_process()          do { } while (0)
  33#define acct_exit_ns(ns)        do { } while (0)
  34#endif
  35
  36/*
  37 * ACCT_VERSION numbers as yet defined:
  38 * 0: old format (until 2.6.7) with 16 bit uid/gid
  39 * 1: extended variant (binary compatible on M68K)
  40 * 2: extended variant (binary compatible on everything except M68K)
  41 * 3: new binary incompatible format (64 bytes)
  42 * 4: new binary incompatible format (128 bytes)
  43 * 5: new binary incompatible format (128 bytes, second half)
  44 *
  45 */
  46
  47#undef ACCT_VERSION
  48#undef AHZ
  49
  50#ifdef CONFIG_BSD_PROCESS_ACCT_V3
  51#define ACCT_VERSION    3
  52#define AHZ             100
  53typedef struct acct_v3 acct_t;
  54#else
  55#ifdef CONFIG_M68K
  56#define ACCT_VERSION    1
  57#else
  58#define ACCT_VERSION    2
  59#endif
  60#define AHZ             (USER_HZ)
  61typedef struct acct acct_t;
  62#endif
  63
  64#include <linux/jiffies.h>
  65/*
  66 * Yet another set of HZ to *HZ helper functions.
  67 * See <linux/jiffies.h> for the original.
  68 */
  69
  70static inline u32 jiffies_to_AHZ(unsigned long x)
  71{
  72#if (TICK_NSEC % (NSEC_PER_SEC / AHZ)) == 0
  73# if HZ < AHZ
  74        return x * (AHZ / HZ);
  75# else
  76        return x / (HZ / AHZ);
  77# endif
  78#else
  79        u64 tmp = (u64)x * TICK_NSEC;
  80        do_div(tmp, (NSEC_PER_SEC / AHZ));
  81        return (long)tmp;
  82#endif
  83}
  84
  85static inline u64 nsec_to_AHZ(u64 x)
  86{
  87#if (NSEC_PER_SEC % AHZ) == 0
  88        do_div(x, (NSEC_PER_SEC / AHZ));
  89#elif (AHZ % 512) == 0
  90        x *= AHZ/512;
  91        do_div(x, (NSEC_PER_SEC / 512));
  92#else
  93        /*
  94         * max relative error 5.7e-8 (1.8s per year) for AHZ <= 1024,
  95         * overflow after 64.99 years.
  96         * exact for AHZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
  97         */
  98        x *= 9;
  99        do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (AHZ/2))
 100                                  / AHZ));
 101#endif
 102        return x;
 103}
 104
 105#endif  /* _LINUX_ACCT_H */
 106