kernel.c 6.13 KB
Newer Older
1
2
3
4
5
6
/** Linux kernel related functions.
 *
 * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
 * @copyright 2017-2018, Institute for Automation of Complex Power Systems, EONERC
 * @license GNU General Public License (version 3)
 *
7
 * VILLAScommon
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
 *
 * 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 3 of the License, or
 * 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, see <http://www.gnu.org/licenses/>.
 *********************************************************************************/

#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
28
#include <inttypes.h>
29
30
31
32
33
34
35
36
37
38
39

#include <sys/types.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <villas/utils.h>
#include <villas/config.h>
#include <villas/kernel/kernel.h>

int kernel_get_cacheline_size()
{
40
#if defined(__linux__) && defined(__x86_64__)
41
42
43
44
45
46
	return sysconf(_SC_LEVEL1_ICACHE_LINESIZE);
#else
	return 64; /** @todo fixme */
#endif
}

47
48
49
50
51
52
53
#if defined(__linux__) || defined(__APPLE__)
int kernel_get_page_size()
{
	return sysconf(_SC_PAGESIZE);
}
#endif

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
#ifdef __linux__

int kernel_module_set_param(const char *module, const char *param, const char *value)
{
	FILE *f;
	char fn[256];

	snprintf(fn, sizeof(fn), "%s/module/%s/parameters/%s", SYSFS_PATH, module, param);
	f = fopen(fn, "w");
	if (!f)
		serror("Failed set parameter %s for kernel module %s to %s", module, param, value);

	debug(LOG_KERNEL | 5, "Set parameter %s of kernel module %s to %s", module, param, value);
	fprintf(f, "%s", value);
	fclose(f);

	return 0;
}

int kernel_module_load(const char *module)
{
	int ret;

	ret = kernel_module_loaded(module);
	if (!ret) {
		debug(LOG_KERNEL | 5, "Kernel module %s already loaded...", module);
		return 0;
	}

	pid_t pid = fork();
	switch (pid) {
		case -1: // error
			return -1;

		case 0:  // child
			execlp("modprobe", "modprobe", module, (char *) 0);
			exit(EXIT_FAILURE);   // exec never returns

		default:
			wait(&ret);

			return kernel_module_loaded(module);
	}
}

int kernel_module_loaded(const char *module)
{
	FILE *f;
	int ret = -1;
	char *line = NULL;
	size_t len = 0;

	f = fopen(PROCFS_PATH "/modules", "r");
	if (!f)
		return -1;

	while (getline(&line, &len, f) >= 0) {
		if (strstr(line, module) == line) {
			ret = 0;
			break;
		}
	}

	free(line);
	fclose(f);

	return ret;
}

int kernel_get_cmdline_param(const char *param, char *buf, size_t len)
{
	int ret;
	char cmdline[512];

	FILE *f = fopen(PROCFS_PATH "/cmdline", "r");
	if (!f)
		return -1;

	if (!fgets(cmdline, sizeof(cmdline), f))
		goto out;

	char *tok = strtok(cmdline, " \t");
	do {
		char key[128], value[128];

		ret = sscanf(tok, "%127[^=]=%127s", key, value);
		if (ret >= 1) {
			if (ret >= 2)
				debug(30, "Found kernel param: %s=%s", key, value);
			else
				debug(30, "Found kernel param: %s", key);

			if (strcmp(param, key) == 0) {
				if (ret >= 2 && buf)
148
					snprintf(buf, len, "%s", value);
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
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249

				return 0; /* found */
			}
		}
	} while((tok = strtok(NULL, " \t")));

out:
	fclose(f);

	return -1; /* not found or error */
}

/* There is no sysconf interface to get the hugepage size */
int kernel_get_hugepage_size()
{
	char *key, *value, *unit, *line = NULL;
	int sz = -1;
	size_t len = 0;
	FILE *f;

	f = fopen(PROCFS_PATH "/meminfo", "r");
	if (!f)
		return -1;

	while (getline(&line, &len, f) != -1) {
		key   = strtok(line, ": ");
		value = strtok(NULL, " ");
		unit  = strtok(NULL, "\n");

		if (!strcmp(key, "Hugepagesize") && !strcmp(unit, "kB")) {
			sz = strtoul(value, NULL, 10) * 1024;
			break;
		}
	}

	free(line);
	fclose(f);

	return sz;
}

int kernel_get_nr_hugepages()
{
	FILE *f;
	int nr, ret;

	f = fopen(PROCFS_PATH "/sys/vm/nr_hugepages", "r");
	if (!f)
		serror("Failed to open %s", PROCFS_PATH "/sys/vm/nr_hugepages");

	ret = fscanf(f, "%d", &nr);
	if (ret != 1)
		nr = -1;

	fclose(f);

	return nr;
}

int kernel_set_nr_hugepages(int nr)
{
	FILE *f;

	f = fopen(PROCFS_PATH "/sys/vm/nr_hugepages", "w");
	if (!f)
		serror("Failed to open %s", PROCFS_PATH "/sys/vm/nr_hugepages");

	fprintf(f, "%d\n", nr);
	fclose(f);

	return 0;
}

#if 0
int kernel_has_cap(cap_value_t cap)
{
	int ret;

	cap_t caps;
	cap_flag_value_t value;

	caps = cap_get_proc();
	if (caps == NULL)
		return -1;

	ret = cap_get_proc(caps);
	if (ret == -1)
		return -1;

	ret = cap_get_flag(caps, cap, CAP_EFFECTIVE, &value);
	if (ret == -1)
		return -1;

	ret = cap_free(caps);
	if (ret)
		return -1;

	return value == CAP_SET ? 0 : -1;
}
#endif

250
int kernel_irq_setaffinity(unsigned irq, uintmax_t aff, uintmax_t *old)
251
252
253
254
255
256
257
258
259
{
	char fn[64];
	FILE *f;
	int ret = 0;

	snprintf(fn, sizeof(fn), "/proc/irq/%u/smp_affinity", irq);

	f = fopen(fn, "w+");
	if (!f)
260
		return -1; /* IRQ does not exist */
261
262
263
264

	if (old)
		ret = fscanf(f, "%jx", old);

265
	fprintf(f, "%jx", aff);
266
267
268
269
270
	fclose(f);

	return ret;
}

271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
int kernel_get_cpu_frequency(uint64_t *freq)
{
	char *line = NULL, *sep, *end;
	size_t len = 0;
	double dfreq;
	int ret;
	FILE *f;

	/* Try to get CPU frequency from cpufreq module */
	f = fopen(SYSFS_PATH "/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq", "r");
	if (!f)
		goto cpuinfo;

	ret = fscanf(f, "%" PRIu64, freq);
	fclose(f);
	if (ret != 1)
		return -1;

	/* cpufreq reports kHz */
	*freq = *freq * 1000;

	return 0;

cpuinfo:
	/* Try to read CPU frequency from /proc/cpuinfo */
	f = fopen(PROCFS_PATH "/cpuinfo", "r");
	if (!f)
		return -1; /* We give up here */

	ret = -1;
	while (getline(&line, &len, f) >= 0) {
		if (strstr(line,  "cpu MHz") == line) {
			ret = 0;
			break;
		}
	}
	if (ret)
		goto out;

	sep = strchr(line, ':');
	if (!sep) {
		ret = -1;
		goto out;
	}

	dfreq = strtod(sep+1, &end);

	if (end == sep+1) {
		ret = -1;
		goto out;
	}

	/* Frequency is given in MHz */
	*freq = dfreq * 1e6;

out:	fclose(f);
	free(line);

	return ret;
}
331
#endif /* __linux__ */