linux/include/linux/sched/loadavg.h
<<
>>
Prefs
   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_SCHED_LOADAVG_H
   3#define _LINUX_SCHED_LOADAVG_H
   4
   5/*
   6 * These are the constant used to fake the fixed-point load-average
   7 * counting. Some notes:
   8 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
   9 *    a load-average precision of 10 bits integer + 11 bits fractional
  10 *  - if you want to count load-averages more often, you need more
  11 *    precision, or rounding will get you. With 2-second counting freq,
  12 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
  13 *    11 bit fractions.
  14 */
  15extern unsigned long avenrun[];         /* Load averages */
  16extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
  17
  18#define FSHIFT          11              /* nr of bits of precision */
  19#define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
  20#define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
  21#define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
  22#define EXP_5           2014            /* 1/exp(5sec/5min) */
  23#define EXP_15          2037            /* 1/exp(5sec/15min) */
  24
  25#define CALC_LOAD(load,exp,n) \
  26        load *= exp; \
  27        load += n*(FIXED_1-exp); \
  28        load >>= FSHIFT;
  29
  30extern void calc_global_load(unsigned long ticks);
  31
  32#endif /* _LINUX_SCHED_LOADAVG_H */
  33