1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* cpufreq-bench CPUFreq microbenchmark |
3 | * |
4 | * Copyright (C) 2008 Christian Kornacker <ckornacker@suse.de> |
5 | */ |
6 | |
7 | #include <stdio.h> |
8 | #include <time.h> |
9 | #include <sys/time.h> |
10 | #include <sys/types.h> |
11 | #include <unistd.h> |
12 | |
13 | #include <sched.h> |
14 | |
15 | #include <cpufreq.h> |
16 | #include <cpupower.h> |
17 | |
18 | #include "config.h" |
19 | #include "system.h" |
20 | |
21 | /** |
22 | * returns time since epoch in µs |
23 | * |
24 | * @retval time |
25 | **/ |
26 | |
27 | long long int get_time() |
28 | { |
29 | struct timeval now; |
30 | |
31 | gettimeofday(&now, NULL); |
32 | |
33 | return (long long int)(now.tv_sec * 1000000LL + now.tv_usec); |
34 | } |
35 | |
36 | /** |
37 | * sets the cpufreq governor |
38 | * |
39 | * @param governor cpufreq governor name |
40 | * @param cpu cpu for which the governor should be set |
41 | * |
42 | * @retval 0 on success |
43 | * @retval -1 when failed |
44 | **/ |
45 | |
46 | int set_cpufreq_governor(char *governor, unsigned int cpu) |
47 | { |
48 | |
49 | dprintf("set %s as cpufreq governor\n" , governor); |
50 | |
51 | if (cpupower_is_cpu_online(cpu) != 1) { |
52 | perror("cpufreq_cpu_exists" ); |
53 | fprintf(stderr, "error: cpu %u does not exist\n" , cpu); |
54 | return -1; |
55 | } |
56 | |
57 | if (cpufreq_modify_policy_governor(cpu, governor) != 0) { |
58 | perror("cpufreq_modify_policy_governor" ); |
59 | fprintf(stderr, "error: unable to set %s governor\n" , governor); |
60 | return -1; |
61 | } |
62 | |
63 | return 0; |
64 | } |
65 | |
66 | /** |
67 | * sets cpu affinity for the process |
68 | * |
69 | * @param cpu cpu# to which the affinity should be set |
70 | * |
71 | * @retval 0 on success |
72 | * @retval -1 when setting the affinity failed |
73 | **/ |
74 | |
75 | int set_cpu_affinity(unsigned int cpu) |
76 | { |
77 | cpu_set_t cpuset; |
78 | |
79 | CPU_ZERO(&cpuset); |
80 | CPU_SET(cpu, &cpuset); |
81 | |
82 | dprintf("set affinity to cpu #%u\n" , cpu); |
83 | |
84 | if (sched_setaffinity(getpid(), sizeof(cpu_set_t), &cpuset) < 0) { |
85 | perror("sched_setaffinity" ); |
86 | fprintf(stderr, "warning: unable to set cpu affinity\n" ); |
87 | return -1; |
88 | } |
89 | |
90 | return 0; |
91 | } |
92 | |
93 | /** |
94 | * sets the process priority parameter |
95 | * |
96 | * @param priority priority value |
97 | * |
98 | * @retval 0 on success |
99 | * @retval -1 when setting the priority failed |
100 | **/ |
101 | |
102 | int set_process_priority(int priority) |
103 | { |
104 | struct sched_param param; |
105 | |
106 | dprintf("set scheduler priority to %i\n" , priority); |
107 | |
108 | param.sched_priority = priority; |
109 | |
110 | if (sched_setscheduler(0, SCHEDULER, ¶m) < 0) { |
111 | perror("sched_setscheduler" ); |
112 | fprintf(stderr, "warning: unable to set scheduler priority\n" ); |
113 | return -1; |
114 | } |
115 | |
116 | return 0; |
117 | } |
118 | |
119 | /** |
120 | * notifies the user that the benchmark may run some time |
121 | * |
122 | * @param config benchmark config values |
123 | * |
124 | **/ |
125 | |
126 | void prepare_user(const struct config *config) |
127 | { |
128 | unsigned long sleep_time = 0; |
129 | unsigned long load_time = 0; |
130 | unsigned int round; |
131 | |
132 | for (round = 0; round < config->rounds; round++) { |
133 | sleep_time += 2 * config->cycles * |
134 | (config->sleep + config->sleep_step * round); |
135 | load_time += 2 * config->cycles * |
136 | (config->load + config->load_step * round) + |
137 | (config->load + config->load_step * round * 4); |
138 | } |
139 | |
140 | if (config->verbose || config->output != stdout) |
141 | printf("approx. test duration: %im\n" , |
142 | (int)((sleep_time + load_time) / 60000000)); |
143 | } |
144 | |
145 | /** |
146 | * sets up the cpu affinity and scheduler priority |
147 | * |
148 | * @param config benchmark config values |
149 | * |
150 | **/ |
151 | |
152 | void prepare_system(const struct config *config) |
153 | { |
154 | if (config->verbose) |
155 | printf("set cpu affinity to cpu #%u\n" , config->cpu); |
156 | |
157 | set_cpu_affinity(config->cpu); |
158 | |
159 | switch (config->prio) { |
160 | case SCHED_HIGH: |
161 | if (config->verbose) |
162 | printf("high priority condition requested\n" ); |
163 | |
164 | set_process_priority(PRIORITY_HIGH); |
165 | break; |
166 | case SCHED_LOW: |
167 | if (config->verbose) |
168 | printf("low priority condition requested\n" ); |
169 | |
170 | set_process_priority(PRIORITY_LOW); |
171 | break; |
172 | default: |
173 | if (config->verbose) |
174 | printf("default priority condition requested\n" ); |
175 | |
176 | set_process_priority(PRIORITY_DEFAULT); |
177 | } |
178 | } |
179 | |
180 | |