1 /*
2 * Copyright (c) 2013-2014 Oracle and/or its affiliates. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of
7 * the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Author: Alexey Kodanev <alexey.kodanev@oracle.com>
19 *
20 * Check support for disabling dynamic overclocking in acpi_cpufreq driver.
21 * Required Linux 3.7+.
22 *
23 * The test compares time spent on sum calculation with/without
24 * boost-disable bit. If boost is enabled we can get a slightly shorter
25 * time period. Measure elapsed time instead of sysfs cpuinfo_cur_freq value,
26 * because after the upstream commit 8673b83bf2f013379453b4779047bf3c6ae387e4,
27 * current cpu frequency became target cpu frequency.
28 */
29
30 #define _GNU_SOURCE
31 #include <sched.h>
32 #include <time.h>
33
34 #include "test.h"
35 #include "lapi/posix_clocks.h"
36 #include "safe_macros.h"
37
38 char *TCID = "cpufreq_boost";
39
40 #define SYSFS_CPU_DIR "/sys/devices/system/cpu/"
41
42 struct cpufreq_driver_info {
43 char *name;
44 int off;
45 char *on_str;
46 char *off_str;
47 char *file;
48 };
49 static const struct cpufreq_driver_info cdrv[] = {
50 { "acpi_cpufreq", 0, "1", "0", SYSFS_CPU_DIR "cpufreq/boost" },
51 { "intel_pstate", 1, "0", "1", SYSFS_CPU_DIR "intel_pstate/no_turbo" },
52 };
53 static int id = -1;
54
55 static int boost_value;
56
57 const char governor[] = SYSFS_CPU_DIR "cpu0/cpufreq/scaling_governor";
58 static char governor_name[16];
59
60 const char maxspeed[] = SYSFS_CPU_DIR "cpu0/cpufreq/scaling_max_freq";
61
cleanup(void)62 static void cleanup(void)
63 {
64 FILE_PRINTF(cdrv[id].file, "%d", boost_value);
65
66 if (governor[0] != '\0')
67 FILE_PRINTF(governor, "%s", governor_name);
68 }
69
setup(void)70 static void setup(void)
71 {
72 int fd;
73 unsigned int i;
74 tst_require_root();
75
76 for (i = 0; i < ARRAY_SIZE(cdrv); ++i) {
77 fd = open(cdrv[i].file, O_RDWR);
78 if (fd == -1)
79 continue;
80
81 id = i;
82 close(fd);
83 break;
84 }
85
86 if (id == -1)
87 tst_brkm(TCONF, NULL, "overclock not supported");
88
89 tst_resm(TINFO, "found '%s' driver, sysfs knob '%s'",
90 cdrv[id].name, cdrv[id].file);
91
92 tst_sig(FORK, DEF_HANDLER, cleanup);
93
94 SAFE_FILE_SCANF(NULL, cdrv[i].file, "%d", &boost_value);
95
96 /* change cpu0 scaling governor */
97 SAFE_FILE_SCANF(NULL, governor, "%s", governor_name);
98 SAFE_FILE_PRINTF(cleanup, governor, "%s", "performance");
99
100 /* use only cpu0 */
101 cpu_set_t set;
102 CPU_ZERO(&set);
103 CPU_SET(0, &set);
104 if (sched_setaffinity(0, sizeof(cpu_set_t), &set) < 0)
105 tst_brkm(TBROK | TERRNO, cleanup, "failed to set CPU0");
106
107 struct sched_param params;
108 params.sched_priority = sched_get_priority_max(SCHED_FIFO);
109 if (sched_setscheduler(getpid(), SCHED_FIFO, ¶ms)) {
110 tst_resm(TWARN | TERRNO,
111 "failed to set FIFO sched with max priority");
112 }
113 }
114
load_cpu(int max_freq_khz)115 static int load_cpu(int max_freq_khz)
116 {
117 int sum = 0, i = 0, total_time_ms;
118 struct timespec tv_start, tv_end;
119
120 const int max_sum = max_freq_khz / 1000;
121 const int units = 1000000; /* Mhz */
122
123 clock_gettime(CLOCK_MONOTONIC_RAW, &tv_start);
124
125 do {
126 for (i = 0; i < units; ++i)
127 asm ("" : : : "memory");
128 } while (++sum < max_sum);
129
130 clock_gettime(CLOCK_MONOTONIC_RAW, &tv_end);
131
132 total_time_ms = (tv_end.tv_sec - tv_start.tv_sec) * 1000 +
133 (tv_end.tv_nsec - tv_start.tv_nsec) / 1000000;
134
135 if (!total_time_ms)
136 tst_brkm(TBROK, cleanup, "time period is 0");
137
138 tst_resm(TINFO, "elapsed time is %d ms", total_time_ms);
139
140 return total_time_ms;
141 }
142
test_run(void)143 static void test_run(void)
144 {
145 int boost_time, boost_off_time, max_freq_khz;
146 SAFE_FILE_SCANF(cleanup, maxspeed, "%d", &max_freq_khz);
147 tst_resm(TINFO, "maximum speed is %d KHz", max_freq_khz);
148
149 /* Enable boost */
150 if (boost_value == cdrv[id].off)
151 SAFE_FILE_PRINTF(cleanup, cdrv[id].file, "%s", cdrv[id].on_str);
152 tst_resm(TINFO, "load CPU0 with boost enabled");
153 boost_time = load_cpu(max_freq_khz);
154
155 /* Disable boost */
156 SAFE_FILE_PRINTF(cleanup, cdrv[id].file, "%s", cdrv[id].off_str);
157 tst_resm(TINFO, "load CPU0 with boost disabled");
158 boost_off_time = load_cpu(max_freq_khz);
159
160 boost_off_time *= .98;
161
162 tst_resm((boost_time < boost_off_time) ? TPASS : TFAIL,
163 "compare time spent with and without boost (-2%%)");
164 }
165
main(int argc,char * argv[])166 int main(int argc, char *argv[])
167 {
168 tst_parse_opts(argc, argv, NULL, NULL);
169
170 setup();
171
172 test_run();
173
174 cleanup();
175
176 tst_exit();
177 }
178