loadavg.h 1.6 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _LINUX_SCHED_LOADAVG_H
  3. #define _LINUX_SCHED_LOADAVG_H
  4. /*
  5. * These are the constant used to fake the fixed-point load-average
  6. * counting. Some notes:
  7. * - 11 bit fractions expand to 22 bits by the multiplies: this gives
  8. * a load-average precision of 10 bits integer + 11 bits fractional
  9. * - if you want to count load-averages more often, you need more
  10. * precision, or rounding will get you. With 2-second counting freq,
  11. * the EXP_n values would be 1981, 2034 and 2043 if still using only
  12. * 11 bit fractions.
  13. */
  14. extern unsigned long avenrun[]; /* Load averages */
  15. extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
  16. #define FSHIFT 11 /* nr of bits of precision */
  17. #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
  18. #define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
  19. #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
  20. #define EXP_5 2014 /* 1/exp(5sec/5min) */
  21. #define EXP_15 2037 /* 1/exp(5sec/15min) */
  22. /*
  23. * a1 = a0 * e + a * (1 - e)
  24. */
  25. static inline unsigned long
  26. calc_load(unsigned long load, unsigned long exp, unsigned long active)
  27. {
  28. unsigned long newload;
  29. newload = load * exp + active * (FIXED_1 - exp);
  30. if (active >= load)
  31. newload += FIXED_1-1;
  32. return newload / FIXED_1;
  33. }
  34. extern unsigned long calc_load_n(unsigned long load, unsigned long exp,
  35. unsigned long active, unsigned int n);
  36. #define LOAD_INT(x) ((x) >> FSHIFT)
  37. #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
  38. extern void calc_global_load(void);
  39. #endif /* _LINUX_SCHED_LOADAVG_H */