1 #ifndef _LINUX_SCHED_LOADAVG_H 2 #define _LINUX_SCHED_LOADAVG_H 3 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 17 #define FSHIFT 11 /* nr of bits of precision */ 18 #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */ 19 #define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */ 20 #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */ 21 #define EXP_5 2014 /* 1/exp(5sec/5min) */ 22 #define EXP_15 2037 /* 1/exp(5sec/15min) */ 23 24 #define CALC_LOAD(load,exp,n) \ 25 load *= exp; \ 26 load += n*(FIXED_1-exp); \ 27 load >>= FSHIFT; 28 29 extern void calc_global_load(unsigned long ticks); 30 31 #endif /* _LINUX_SCHED_LOADAVG_H */ 32