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 <errno.h>
32 #include <sched.h>
33 #include <time.h>
34
35 #include "test.h"
36 #include "lapi/posix_clocks.h"
37 #include "safe_macros.h"
38
39 char *TCID = "cpufreq_boost";
40
41 #define SYSFS_CPU_DIR "/sys/devices/system/cpu/"
42
43 struct cpufreq_driver_info {
44 char *name;
45 int off;
46 char *on_str;
47 char *off_str;
48 char *file;
49 };
50 static const struct cpufreq_driver_info cdrv[] = {
51 { "acpi_cpufreq", 0, "1", "0", SYSFS_CPU_DIR "cpufreq/boost" },
52 { "intel_pstate", 1, "0", "1", SYSFS_CPU_DIR "intel_pstate/no_turbo" },
53 };
54 static int id = -1;
55
56 static int boost_value;
57
58 const char governor[] = SYSFS_CPU_DIR "cpu0/cpufreq/scaling_governor";
59 static char governor_name[16];
60
61 const char maxspeed[] = SYSFS_CPU_DIR "cpu0/cpufreq/scaling_max_freq";
62
check_set_turbo(char * file,char * off)63 static void check_set_turbo(char *file, char *off)
64 {
65 int fd;
66
67 fd = SAFE_OPEN(NULL, file, O_WRONLY);
68
69 /* We try to skip test when getting EPERM. */
70 if (write(fd, off, 1) == -1 && errno == EPERM) {
71 SAFE_CLOSE(NULL, fd);
72 tst_brkm(TCONF, NULL,
73 "Turbo is disabled by BIOS or unavailable on processor");
74 }
75
76 SAFE_CLOSE(NULL, fd);
77 }
78
cleanup(void)79 static void cleanup(void)
80 {
81 FILE_PRINTF(cdrv[id].file, "%d", boost_value);
82
83 if (governor[0] != '\0')
84 FILE_PRINTF(governor, "%s", governor_name);
85 }
86
setup(void)87 static void setup(void)
88 {
89 int fd;
90 unsigned int i;
91 tst_require_root();
92
93 if (tst_is_virt(VIRT_ANY))
94 tst_brkm(TCONF, NULL, "running in a virtual machine, overclock not reliably measureable");
95
96 for (i = 0; i < ARRAY_SIZE(cdrv); ++i) {
97 fd = open(cdrv[i].file, O_RDWR);
98 if (fd == -1)
99 continue;
100
101 id = i;
102 close(fd);
103 break;
104 }
105
106 if (id == -1)
107 tst_brkm(TCONF, NULL, "overclock not supported");
108
109 tst_resm(TINFO, "found '%s' driver, sysfs knob '%s'",
110 cdrv[id].name, cdrv[id].file);
111
112 tst_sig(FORK, DEF_HANDLER, cleanup);
113
114 SAFE_FILE_SCANF(NULL, cdrv[i].file, "%d", &boost_value);
115
116 /* For intel_pstate, we cannot write data into intel_pstate/no_turbo
117 * and return EPERM if turbo is disabled by BIOS or unavailable on
118 * processor. We should check this case by writing original data.
119 */
120 if (!strcmp(cdrv[i].name, "intel_pstate") && boost_value == cdrv[i].off)
121 check_set_turbo(cdrv[i].file, cdrv[i].off_str);
122
123 /* change cpu0 scaling governor */
124 SAFE_FILE_SCANF(NULL, governor, "%s", governor_name);
125 SAFE_FILE_PRINTF(cleanup, governor, "%s", "performance");
126
127 /* use only cpu0 */
128 cpu_set_t set;
129 CPU_ZERO(&set);
130 CPU_SET(0, &set);
131 if (sched_setaffinity(0, sizeof(cpu_set_t), &set) < 0)
132 tst_brkm(TBROK | TERRNO, cleanup, "failed to set CPU0");
133
134 struct sched_param params;
135 params.sched_priority = sched_get_priority_max(SCHED_FIFO);
136 if (sched_setscheduler(getpid(), SCHED_FIFO, ¶ms)) {
137 tst_resm(TWARN | TERRNO,
138 "failed to set FIFO sched with max priority");
139 }
140 }
141
load_cpu(int max_freq_khz)142 static int load_cpu(int max_freq_khz)
143 {
144 int sum = 0, i = 0, total_time_ms;
145 struct timespec tv_start, tv_end;
146
147 const int max_sum = max_freq_khz / 1000;
148 const int units = 1000000; /* Mhz */
149
150 clock_gettime(CLOCK_MONOTONIC_RAW, &tv_start);
151
152 do {
153 for (i = 0; i < units; ++i)
154 asm ("" : : : "memory");
155 } while (++sum < max_sum);
156
157 clock_gettime(CLOCK_MONOTONIC_RAW, &tv_end);
158
159 total_time_ms = (tv_end.tv_sec - tv_start.tv_sec) * 1000 +
160 (tv_end.tv_nsec - tv_start.tv_nsec) / 1000000;
161
162 if (!total_time_ms)
163 tst_brkm(TBROK, cleanup, "time period is 0");
164
165 tst_resm(TINFO, "elapsed time is %d ms", total_time_ms);
166
167 return total_time_ms;
168 }
169
test_run(void)170 static void test_run(void)
171 {
172 int boost_time, boost_off_time, max_freq_khz;
173 SAFE_FILE_SCANF(cleanup, maxspeed, "%d", &max_freq_khz);
174 tst_resm(TINFO, "maximum speed is %d KHz", max_freq_khz);
175
176 /* Enable boost */
177 if (boost_value == cdrv[id].off)
178 SAFE_FILE_PRINTF(cleanup, cdrv[id].file, "%s", cdrv[id].on_str);
179 tst_resm(TINFO, "load CPU0 with boost enabled");
180 boost_time = load_cpu(max_freq_khz);
181
182 /* Disable boost */
183 SAFE_FILE_PRINTF(cleanup, cdrv[id].file, "%s", cdrv[id].off_str);
184 tst_resm(TINFO, "load CPU0 with boost disabled");
185 boost_off_time = load_cpu(max_freq_khz);
186
187 boost_off_time *= .98;
188
189 tst_resm((boost_time < boost_off_time) ? TPASS : TFAIL,
190 "compare time spent with and without boost (-2%%)");
191 }
192
main(int argc,char * argv[])193 int main(int argc, char *argv[])
194 {
195 tst_parse_opts(argc, argv, NULL, NULL);
196
197 setup();
198
199 test_run();
200
201 cleanup();
202
203 tst_exit();
204 }
205