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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
4f17722c IM |
2 | #ifndef _LINUX_SCHED_LOADAVG_H |
3 | #define _LINUX_SCHED_LOADAVG_H | |
4 | ||
dea38c74 IM |
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 | ||
8508cf3f JW |
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 | #define LOAD_INT(x) ((x) >> FSHIFT) | |
41 | #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100) | |
dea38c74 IM |
42 | |
43 | extern void calc_global_load(unsigned long ticks); | |
44 | ||
4f17722c | 45 | #endif /* _LINUX_SCHED_LOADAVG_H */ |