1/*
2 * The following program is used to generate the constants for
3 * computing sched averages.
4 *
5 * ==============================================================
6 *		C program (compile with -lm)
7 * ==============================================================
8 */
9
10#include <math.h>
11#include <stdio.h>
12
13#define HALFLIFE 32
14#define SHIFT 32
15
16double y;
17
18void calc_runnable_avg_yN_inv(void)
19{
20	int i;
21	unsigned int x;
22
23	/* To silence -Wunused-but-set-variable warnings. */
24	printf("static const u32 runnable_avg_yN_inv[] __maybe_unused = {");
25	for (i = 0; i < HALFLIFE; i++) {
26		x = ((1UL<<32)-1)*pow(y, i);
27
28		if (i % 6 == 0) printf("\n\t");
29		printf("0x%8x, ", x);
30	}
31	printf("\n};\n\n");
32}
33
34int sum = 1024;
35
36void calc_runnable_avg_yN_sum(void)
37{
38	int i;
39
40	printf("static const u32 runnable_avg_yN_sum[] = {\n\t    0,");
41	for (i = 1; i <= HALFLIFE; i++) {
42		if (i == 1)
43			sum *= y;
44		else
45			sum = sum*y + 1024*y;
46
47		if (i % 11 == 0)
48			printf("\n\t");
49
50		printf("%5d,", sum);
51	}
52	printf("\n};\n\n");
53}
54
55int n = -1;
56/* first period */
57long max = 1024;
58
59void calc_converged_max(void)
60{
61	long last = 0, y_inv = ((1UL<<32)-1)*y;
62
63	for (; ; n++) {
64		if (n > -1)
65			max = ((max*y_inv)>>SHIFT) + 1024;
66			/*
67			 * This is the same as:
68			 * max = max*y + 1024;
69			 */
70
71		if (last == max)
72			break;
73
74		last = max;
75	}
76	n--;
77	printf("#define LOAD_AVG_PERIOD %d\n", HALFLIFE);
78	printf("#define LOAD_AVG_MAX %ld\n", max);
79//	printf("#define LOAD_AVG_MAX_N %d\n\n", n);
80}
81
82void calc_accumulated_sum_32(void)
83{
84	int i, x = sum;
85
86	printf("static const u32 __accumulated_sum_N32[] = {\n\t     0,");
87	for (i = 1; i <= n/HALFLIFE+1; i++) {
88		if (i > 1)
89			x = x/2 + sum;
90
91		if (i % 6 == 0)
92			printf("\n\t");
93
94		printf("%6d,", x);
95	}
96	printf("\n};\n\n");
97}
98
99void main(void)
100{
101	printf("/* Generated by Documentation/scheduler/sched-pelt; do not modify. */\n\n");
102
103	y = pow(0.5, 1/(double)HALFLIFE);
104
105	calc_runnable_avg_yN_inv();
106//	calc_runnable_avg_yN_sum();
107	calc_converged_max();
108//	calc_accumulated_sum_32();
109}
110