summaryrefslogtreecommitdiffstats
path: root/tools/power/cpupower/bench/system.c
blob: 2bb3eef7d5c1fbf36d420be2801e74b4f7eeb049 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
/*  cpufreq-bench CPUFreq microbenchmark
 *
 *  Copyright (C) 2008 Christian Kornacker <ckornacker@suse.de>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <stdio.h>
#include <time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

#include <sched.h>

#include <cpufreq.h>
#include <cpupower.h>

#include "config.h"
#include "system.h"

/**
 * returns time since epoch in µs
 *
 * @retval time
 **/

long long int get_time()
{
	struct timeval now;

	gettimeofday(&now, NULL);

	return (long long int)(now.tv_sec * 1000000LL + now.tv_usec);
}

/**
 * sets the cpufreq governor
 *
 * @param governor cpufreq governor name
 * @param cpu cpu for which the governor should be set
 *
 * @retval 0 on success
 * @retval -1 when failed
 **/

int set_cpufreq_governor(char *governor, unsigned int cpu)
{

	dprintf("set %s as cpufreq governor\n", governor);

	if (cpupower_is_cpu_online(cpu) != 1) {
		perror("cpufreq_cpu_exists");
		fprintf(stderr, "error: cpu %u does not exist\n", cpu);
		return -1;
	}

	if (cpufreq_modify_policy_governor(cpu, governor) != 0) {
		perror("cpufreq_modify_policy_governor");
		fprintf(stderr, "error: unable to set %s governor\n", governor);
		return -1;
	}

	return 0;
}

/**
 * sets cpu affinity for the process
 *
 * @param cpu cpu# to which the affinity should be set
 *
 * @retval 0 on success
 * @retval -1 when setting the affinity failed
 **/

int set_cpu_affinity(unsigned int cpu)
{
	cpu_set_t cpuset;

	CPU_ZERO(&cpuset);
	CPU_SET(cpu, &cpuset);

	dprintf("set affinity to cpu #%u\n", cpu);

	if (sched_setaffinity(getpid(), sizeof(cpu_set_t), &cpuset) < 0) {
		perror("sched_setaffinity");
		fprintf(stderr, "warning: unable to set cpu affinity\n");
		return -1;
	}

	return 0;
}

/**
 * sets the process priority parameter
 *
 * @param priority priority value
 *
 * @retval 0 on success
 * @retval -1 when setting the priority failed
 **/

int set_process_priority(int priority)
{
	struct sched_param param;

	dprintf("set scheduler priority to %i\n", priority);

	param.sched_priority = priority;

	if (sched_setscheduler(0, SCHEDULER, &param) < 0) {
		perror("sched_setscheduler");
		fprintf(stderr, "warning: unable to set scheduler priority\n");
		return -1;
	}

	return 0;
}

/**
 * notifies the user that the benchmark may run some time
 *
 * @param config benchmark config values
 *
 **/

void prepare_user(const struct config *config)
{
	unsigned long sleep_time = 0;
	unsigned long load_time = 0;
	unsigned int round;

	for (round = 0; round < config->rounds; round++) {
		sleep_time +=  2 * config->cycles *
			(config->sleep + config->sleep_step * round);
		load_time += 2 * config->cycles *
			(config->load + config->load_step * round) +
			(config->load + config->load_step * round * 4);
	}

	if (config->verbose || config->output != stdout)
		printf("approx. test duration: %im\n",
		       (int)((sleep_time + load_time) / 60000000));
}

/**
 * sets up the cpu affinity and scheduler priority
 *
 * @param config benchmark config values
 *
 **/

void prepare_system(const struct config *config)
{
	if (config->verbose)
		printf("set cpu affinity to cpu #%u\n", config->cpu);

	set_cpu_affinity(config->cpu);

	switch (config->prio) {
	case SCHED_HIGH:
		if (config->verbose)
			printf("high priority condition requested\n");

		set_process_priority(PRIORITY_HIGH);
		break;
	case SCHED_LOW:
		if (config->verbose)
			printf("low priority condition requested\n");

		set_process_priority(PRIORITY_LOW);
		break;
	default:
		if (config->verbose)
			printf("default priority condition requested\n");

		set_process_priority(PRIORITY_DEFAULT);
	}
}