1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _LINUX_SCHED_LOADAVG_H
3*4882a593Smuzhiyun #define _LINUX_SCHED_LOADAVG_H
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun /*
6*4882a593Smuzhiyun * These are the constant used to fake the fixed-point load-average
7*4882a593Smuzhiyun * counting. Some notes:
8*4882a593Smuzhiyun * - 11 bit fractions expand to 22 bits by the multiplies: this gives
9*4882a593Smuzhiyun * a load-average precision of 10 bits integer + 11 bits fractional
10*4882a593Smuzhiyun * - if you want to count load-averages more often, you need more
11*4882a593Smuzhiyun * precision, or rounding will get you. With 2-second counting freq,
12*4882a593Smuzhiyun * the EXP_n values would be 1981, 2034 and 2043 if still using only
13*4882a593Smuzhiyun * 11 bit fractions.
14*4882a593Smuzhiyun */
15*4882a593Smuzhiyun extern unsigned long avenrun[]; /* Load averages */
16*4882a593Smuzhiyun extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun #define FSHIFT 11 /* nr of bits of precision */
19*4882a593Smuzhiyun #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
20*4882a593Smuzhiyun #define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
21*4882a593Smuzhiyun #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
22*4882a593Smuzhiyun #define EXP_5 2014 /* 1/exp(5sec/5min) */
23*4882a593Smuzhiyun #define EXP_15 2037 /* 1/exp(5sec/15min) */
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun /*
26*4882a593Smuzhiyun * a1 = a0 * e + a * (1 - e)
27*4882a593Smuzhiyun */
28*4882a593Smuzhiyun static inline unsigned long
calc_load(unsigned long load,unsigned long exp,unsigned long active)29*4882a593Smuzhiyun calc_load(unsigned long load, unsigned long exp, unsigned long active)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun unsigned long newload;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun newload = load * exp + active * (FIXED_1 - exp);
34*4882a593Smuzhiyun if (active >= load)
35*4882a593Smuzhiyun newload += FIXED_1-1;
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun return newload / FIXED_1;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun extern unsigned long calc_load_n(unsigned long load, unsigned long exp,
41*4882a593Smuzhiyun unsigned long active, unsigned int n);
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun #define LOAD_INT(x) ((x) >> FSHIFT)
44*4882a593Smuzhiyun #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun extern void calc_global_load(void);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun #endif /* _LINUX_SCHED_LOADAVG_H */
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