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 | */ |
15 | extern unsigned long avenrun[]; /* Load averages */ |
16 | extern 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 | /* |
26 | * a1 = a0 * e + a * (1 - e) |
27 | */ |
28 | static inline unsigned long |
29 | calc_load(unsigned long load, unsigned long exp, unsigned long active) |
30 | { |
31 | unsigned long newload; |
32 | |
33 | newload = load * exp + active * (FIXED_1 - exp); |
34 | if (active >= load) |
35 | newload += FIXED_1-1; |
36 | |
37 | return newload / FIXED_1; |
38 | } |
39 | |
40 | extern unsigned long calc_load_n(unsigned long load, unsigned long exp, |
41 | unsigned long active, unsigned int n); |
42 | |
43 | #define LOAD_INT(x) ((x) >> FSHIFT) |
44 | #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100) |
45 | |
46 | extern void calc_global_load(void); |
47 | |
48 | #endif /* _LINUX_SCHED_LOADAVG_H */ |
49 | |