1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Basic resctrl file system operations
4 *
5 * Copyright (C) 2018 Intel Corporation
6 *
7 * Authors:
8 * Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
9 * Fenghua Yu <fenghua.yu@intel.com>
10 */
11 #include <limits.h>
12
13 #include "resctrl.h"
14
find_resctrl_mount(char * buffer)15 static int find_resctrl_mount(char *buffer)
16 {
17 FILE *mounts;
18 char line[256], *fs, *mntpoint;
19
20 mounts = fopen("/proc/mounts", "r");
21 if (!mounts) {
22 ksft_perror("/proc/mounts");
23 return -ENXIO;
24 }
25 while (!feof(mounts)) {
26 if (!fgets(line, 256, mounts))
27 break;
28 fs = strtok(line, " \t");
29 if (!fs)
30 continue;
31 mntpoint = strtok(NULL, " \t");
32 if (!mntpoint)
33 continue;
34 fs = strtok(NULL, " \t");
35 if (!fs)
36 continue;
37 if (strcmp(fs, "resctrl"))
38 continue;
39
40 fclose(mounts);
41 if (buffer)
42 strncpy(buffer, mntpoint, 256);
43
44 return 0;
45 }
46
47 fclose(mounts);
48
49 return -ENOENT;
50 }
51
52 /*
53 * mount_resctrlfs - Mount resctrl FS at /sys/fs/resctrl
54 *
55 * Mounts resctrl FS. Fails if resctrl FS is already mounted to avoid
56 * pre-existing settings interfering with the test results.
57 *
58 * Return: 0 on success, non-zero on failure
59 */
mount_resctrlfs(void)60 int mount_resctrlfs(void)
61 {
62 int ret;
63
64 ret = find_resctrl_mount(NULL);
65 if (ret != -ENOENT)
66 return -1;
67
68 ksft_print_msg("Mounting resctrl to \"%s\"\n", RESCTRL_PATH);
69 ret = mount("resctrl", RESCTRL_PATH, "resctrl", 0, NULL);
70 if (ret)
71 ksft_perror("mount");
72
73 return ret;
74 }
75
umount_resctrlfs(void)76 int umount_resctrlfs(void)
77 {
78 char mountpoint[256];
79 int ret;
80
81 ret = find_resctrl_mount(mountpoint);
82 if (ret == -ENOENT)
83 return 0;
84 if (ret)
85 return ret;
86
87 if (umount(mountpoint)) {
88 ksft_perror("Unable to umount resctrl");
89
90 return errno;
91 }
92
93 return 0;
94 }
95
96 /*
97 * get_resource_id - Get socket number/l3 id for a specified CPU
98 * @cpu_no: CPU number
99 * @resource_id: Socket number or l3_id
100 *
101 * Return: >= 0 on success, < 0 on failure.
102 */
get_resource_id(int cpu_no,int * resource_id)103 int get_resource_id(int cpu_no, int *resource_id)
104 {
105 char phys_pkg_path[1024];
106 FILE *fp;
107
108 if (get_vendor() == ARCH_AMD)
109 sprintf(phys_pkg_path, "%s%d/cache/index3/id",
110 PHYS_ID_PATH, cpu_no);
111 else
112 sprintf(phys_pkg_path, "%s%d/topology/physical_package_id",
113 PHYS_ID_PATH, cpu_no);
114
115 fp = fopen(phys_pkg_path, "r");
116 if (!fp) {
117 ksft_perror("Failed to open physical_package_id");
118
119 return -1;
120 }
121 if (fscanf(fp, "%d", resource_id) <= 0) {
122 ksft_perror("Could not get socket number or l3 id");
123 fclose(fp);
124
125 return -1;
126 }
127 fclose(fp);
128
129 return 0;
130 }
131
132 /*
133 * get_cache_size - Get cache size for a specified CPU
134 * @cpu_no: CPU number
135 * @cache_type: Cache level L2/L3
136 * @cache_size: pointer to cache_size
137 *
138 * Return: = 0 on success, < 0 on failure.
139 */
get_cache_size(int cpu_no,char * cache_type,unsigned long * cache_size)140 int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size)
141 {
142 char cache_path[1024], cache_str[64];
143 int length, i, cache_num;
144 FILE *fp;
145
146 if (!strcmp(cache_type, "L3")) {
147 cache_num = 3;
148 } else if (!strcmp(cache_type, "L2")) {
149 cache_num = 2;
150 } else {
151 ksft_print_msg("Invalid cache level\n");
152 return -1;
153 }
154
155 sprintf(cache_path, "/sys/bus/cpu/devices/cpu%d/cache/index%d/size",
156 cpu_no, cache_num);
157 fp = fopen(cache_path, "r");
158 if (!fp) {
159 ksft_perror("Failed to open cache size");
160
161 return -1;
162 }
163 if (fscanf(fp, "%63s", cache_str) <= 0) {
164 ksft_perror("Could not get cache_size");
165 fclose(fp);
166
167 return -1;
168 }
169 fclose(fp);
170
171 length = (int)strlen(cache_str);
172
173 *cache_size = 0;
174
175 for (i = 0; i < length; i++) {
176 if ((cache_str[i] >= '0') && (cache_str[i] <= '9'))
177
178 *cache_size = *cache_size * 10 + (cache_str[i] - '0');
179
180 else if (cache_str[i] == 'K')
181
182 *cache_size = *cache_size * 1024;
183
184 else if (cache_str[i] == 'M')
185
186 *cache_size = *cache_size * 1024 * 1024;
187
188 else
189 break;
190 }
191
192 return 0;
193 }
194
195 #define CORE_SIBLINGS_PATH "/sys/bus/cpu/devices/cpu"
196
197 /*
198 * get_cbm_mask - Get cbm mask for given cache
199 * @cache_type: Cache level L2/L3
200 * @cbm_mask: cbm_mask returned as a string
201 *
202 * Return: = 0 on success, < 0 on failure.
203 */
get_cbm_mask(char * cache_type,char * cbm_mask)204 int get_cbm_mask(char *cache_type, char *cbm_mask)
205 {
206 char cbm_mask_path[1024];
207 FILE *fp;
208
209 if (!cbm_mask)
210 return -1;
211
212 sprintf(cbm_mask_path, "%s/%s/cbm_mask", INFO_PATH, cache_type);
213
214 fp = fopen(cbm_mask_path, "r");
215 if (!fp) {
216 ksft_perror("Failed to open cache level");
217
218 return -1;
219 }
220 if (fscanf(fp, "%s", cbm_mask) <= 0) {
221 ksft_perror("Could not get max cbm_mask");
222 fclose(fp);
223
224 return -1;
225 }
226 fclose(fp);
227
228 return 0;
229 }
230
231 /*
232 * get_core_sibling - Get sibling core id from the same socket for given CPU
233 * @cpu_no: CPU number
234 *
235 * Return: > 0 on success, < 0 on failure.
236 */
get_core_sibling(int cpu_no)237 int get_core_sibling(int cpu_no)
238 {
239 char core_siblings_path[1024], cpu_list_str[64];
240 int sibling_cpu_no = -1;
241 FILE *fp;
242
243 sprintf(core_siblings_path, "%s%d/topology/core_siblings_list",
244 CORE_SIBLINGS_PATH, cpu_no);
245
246 fp = fopen(core_siblings_path, "r");
247 if (!fp) {
248 ksft_perror("Failed to open core siblings path");
249
250 return -1;
251 }
252 if (fscanf(fp, "%s", cpu_list_str) <= 0) {
253 ksft_perror("Could not get core_siblings list");
254 fclose(fp);
255
256 return -1;
257 }
258 fclose(fp);
259
260 char *token = strtok(cpu_list_str, "-,");
261
262 while (token) {
263 sibling_cpu_no = atoi(token);
264 /* Skipping core 0 as we don't want to run test on core 0 */
265 if (sibling_cpu_no != 0 && sibling_cpu_no != cpu_no)
266 break;
267 token = strtok(NULL, "-,");
268 }
269
270 return sibling_cpu_no;
271 }
272
273 /*
274 * taskset_benchmark - Taskset PID (i.e. benchmark) to a specified cpu
275 * @bm_pid: PID that should be binded
276 * @cpu_no: CPU number at which the PID would be binded
277 *
278 * Return: 0 on success, non-zero on failure
279 */
taskset_benchmark(pid_t bm_pid,int cpu_no)280 int taskset_benchmark(pid_t bm_pid, int cpu_no)
281 {
282 cpu_set_t my_set;
283
284 CPU_ZERO(&my_set);
285 CPU_SET(cpu_no, &my_set);
286
287 if (sched_setaffinity(bm_pid, sizeof(cpu_set_t), &my_set)) {
288 ksft_perror("Unable to taskset benchmark");
289
290 return -1;
291 }
292
293 return 0;
294 }
295
296 /*
297 * create_grp - Create a group only if one doesn't exist
298 * @grp_name: Name of the group
299 * @grp: Full path and name of the group
300 * @parent_grp: Full path and name of the parent group
301 *
302 * Return: 0 on success, non-zero on failure
303 */
create_grp(const char * grp_name,char * grp,const char * parent_grp)304 static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
305 {
306 int found_grp = 0;
307 struct dirent *ep;
308 DIR *dp;
309
310 /*
311 * At this point, we are guaranteed to have resctrl FS mounted and if
312 * length of grp_name == 0, it means, user wants to use root con_mon
313 * grp, so do nothing
314 */
315 if (strlen(grp_name) == 0)
316 return 0;
317
318 /* Check if requested grp exists or not */
319 dp = opendir(parent_grp);
320 if (dp) {
321 while ((ep = readdir(dp)) != NULL) {
322 if (strcmp(ep->d_name, grp_name) == 0)
323 found_grp = 1;
324 }
325 closedir(dp);
326 } else {
327 ksft_perror("Unable to open resctrl for group");
328
329 return -1;
330 }
331
332 /* Requested grp doesn't exist, hence create it */
333 if (found_grp == 0) {
334 if (mkdir(grp, 0) == -1) {
335 ksft_perror("Unable to create group");
336
337 return -1;
338 }
339 }
340
341 return 0;
342 }
343
write_pid_to_tasks(char * tasks,pid_t pid)344 static int write_pid_to_tasks(char *tasks, pid_t pid)
345 {
346 FILE *fp;
347
348 fp = fopen(tasks, "w");
349 if (!fp) {
350 ksft_perror("Failed to open tasks file");
351
352 return -1;
353 }
354 if (fprintf(fp, "%d\n", pid) < 0) {
355 ksft_print_msg("Failed to write pid to tasks file\n");
356 fclose(fp);
357
358 return -1;
359 }
360 fclose(fp);
361
362 return 0;
363 }
364
365 /*
366 * write_bm_pid_to_resctrl - Write a PID (i.e. benchmark) to resctrl FS
367 * @bm_pid: PID that should be written
368 * @ctrlgrp: Name of the control monitor group (con_mon grp)
369 * @mongrp: Name of the monitor group (mon grp)
370 * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc)
371 *
372 * If a con_mon grp is requested, create it and write pid to it, otherwise
373 * write pid to root con_mon grp.
374 * If a mon grp is requested, create it and write pid to it, otherwise
375 * pid is not written, this means that pid is in con_mon grp and hence
376 * should consult con_mon grp's mon_data directory for results.
377 *
378 * Return: 0 on success, non-zero on failure
379 */
write_bm_pid_to_resctrl(pid_t bm_pid,char * ctrlgrp,char * mongrp,char * resctrl_val)380 int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
381 char *resctrl_val)
382 {
383 char controlgroup[128], monitorgroup[512], monitorgroup_p[256];
384 char tasks[1024];
385 int ret = 0;
386
387 if (strlen(ctrlgrp))
388 sprintf(controlgroup, "%s/%s", RESCTRL_PATH, ctrlgrp);
389 else
390 sprintf(controlgroup, "%s", RESCTRL_PATH);
391
392 /* Create control and monitoring group and write pid into it */
393 ret = create_grp(ctrlgrp, controlgroup, RESCTRL_PATH);
394 if (ret)
395 goto out;
396 sprintf(tasks, "%s/tasks", controlgroup);
397 ret = write_pid_to_tasks(tasks, bm_pid);
398 if (ret)
399 goto out;
400
401 /* Create mon grp and write pid into it for "mbm" and "cmt" test */
402 if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)) ||
403 !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
404 if (strlen(mongrp)) {
405 sprintf(monitorgroup_p, "%s/mon_groups", controlgroup);
406 sprintf(monitorgroup, "%s/%s", monitorgroup_p, mongrp);
407 ret = create_grp(mongrp, monitorgroup, monitorgroup_p);
408 if (ret)
409 goto out;
410
411 sprintf(tasks, "%s/mon_groups/%s/tasks",
412 controlgroup, mongrp);
413 ret = write_pid_to_tasks(tasks, bm_pid);
414 if (ret)
415 goto out;
416 }
417 }
418
419 out:
420 ksft_print_msg("Writing benchmark parameters to resctrl FS\n");
421 if (ret)
422 ksft_print_msg("Failed writing to resctrlfs\n");
423
424 return ret;
425 }
426
427 /*
428 * write_schemata - Update schemata of a con_mon grp
429 * @ctrlgrp: Name of the con_mon grp
430 * @schemata: Schemata that should be updated to
431 * @cpu_no: CPU number that the benchmark PID is binded to
432 * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc)
433 *
434 * Update schemata of a con_mon grp *only* if requested resctrl feature is
435 * allocation type
436 *
437 * Return: 0 on success, non-zero on failure
438 */
write_schemata(char * ctrlgrp,char * schemata,int cpu_no,char * resctrl_val)439 int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
440 {
441 char controlgroup[1024], schema[1024], reason[64];
442 int resource_id, ret = 0;
443 FILE *fp;
444
445 if (strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) &&
446 strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) &&
447 strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR)) &&
448 strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
449 return -ENOENT;
450
451 if (!schemata) {
452 ksft_print_msg("Skipping empty schemata update\n");
453
454 return -1;
455 }
456
457 if (get_resource_id(cpu_no, &resource_id) < 0) {
458 sprintf(reason, "Failed to get resource id");
459 ret = -1;
460
461 goto out;
462 }
463
464 if (strlen(ctrlgrp) != 0)
465 sprintf(controlgroup, "%s/%s/schemata", RESCTRL_PATH, ctrlgrp);
466 else
467 sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
468
469 if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR)) ||
470 !strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
471 sprintf(schema, "%s%d%c%s", "L3:", resource_id, '=', schemata);
472 if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) ||
473 !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)))
474 sprintf(schema, "%s%d%c%s", "MB:", resource_id, '=', schemata);
475
476 fp = fopen(controlgroup, "w");
477 if (!fp) {
478 sprintf(reason, "Failed to open control group");
479 ret = -1;
480
481 goto out;
482 }
483
484 if (fprintf(fp, "%s\n", schema) < 0) {
485 sprintf(reason, "Failed to write schemata in control group");
486 fclose(fp);
487 ret = -1;
488
489 goto out;
490 }
491 fclose(fp);
492
493 out:
494 ksft_print_msg("Write schema \"%s\" to resctrl FS%s%s\n",
495 schema, ret ? " # " : "",
496 ret ? reason : "");
497
498 return ret;
499 }
500
check_resctrlfs_support(void)501 bool check_resctrlfs_support(void)
502 {
503 FILE *inf = fopen("/proc/filesystems", "r");
504 DIR *dp;
505 char *res;
506 bool ret = false;
507
508 if (!inf)
509 return false;
510
511 res = fgrep(inf, "nodev\tresctrl\n");
512
513 if (res) {
514 ret = true;
515 free(res);
516 }
517
518 fclose(inf);
519
520 ksft_print_msg("%s Check kernel supports resctrl filesystem\n",
521 ret ? "Pass:" : "Fail:");
522
523 if (!ret)
524 return ret;
525
526 dp = opendir(RESCTRL_PATH);
527 ksft_print_msg("%s Check resctrl mountpoint \"%s\" exists\n",
528 dp ? "Pass:" : "Fail:", RESCTRL_PATH);
529 if (dp)
530 closedir(dp);
531
532 ksft_print_msg("resctrl filesystem %s mounted\n",
533 find_resctrl_mount(NULL) ? "not" : "is");
534
535 return ret;
536 }
537
fgrep(FILE * inf,const char * str)538 char *fgrep(FILE *inf, const char *str)
539 {
540 char line[256];
541 int slen = strlen(str);
542
543 while (!feof(inf)) {
544 if (!fgets(line, 256, inf))
545 break;
546 if (strncmp(line, str, slen))
547 continue;
548
549 return strdup(line);
550 }
551
552 return NULL;
553 }
554
555 /*
556 * validate_resctrl_feature_request - Check if requested feature is valid.
557 * @resource: Required resource (e.g., MB, L3, L2, L3_MON, etc.)
558 * @feature: Required monitor feature (in mon_features file). Can only be
559 * set for L3_MON. Must be NULL for all other resources.
560 *
561 * Return: True if the resource/feature is supported, else false. False is
562 * also returned if resctrl FS is not mounted.
563 */
validate_resctrl_feature_request(const char * resource,const char * feature)564 bool validate_resctrl_feature_request(const char *resource, const char *feature)
565 {
566 char res_path[PATH_MAX];
567 struct stat statbuf;
568 char *res;
569 FILE *inf;
570 int ret;
571
572 if (!resource)
573 return false;
574
575 ret = find_resctrl_mount(NULL);
576 if (ret)
577 return false;
578
579 snprintf(res_path, sizeof(res_path), "%s/%s", INFO_PATH, resource);
580
581 if (stat(res_path, &statbuf))
582 return false;
583
584 if (!feature)
585 return true;
586
587 snprintf(res_path, sizeof(res_path), "%s/%s/mon_features", INFO_PATH, resource);
588 inf = fopen(res_path, "r");
589 if (!inf)
590 return false;
591
592 res = fgrep(inf, feature);
593 free(res);
594 fclose(inf);
595
596 return !!res;
597 }
598
filter_dmesg(void)599 int filter_dmesg(void)
600 {
601 char line[1024];
602 FILE *fp;
603 int pipefds[2];
604 pid_t pid;
605 int ret;
606
607 ret = pipe(pipefds);
608 if (ret) {
609 ksft_perror("pipe");
610 return ret;
611 }
612 fflush(stdout);
613 pid = fork();
614 if (pid == 0) {
615 close(pipefds[0]);
616 dup2(pipefds[1], STDOUT_FILENO);
617 execlp("dmesg", "dmesg", NULL);
618 ksft_perror("Executing dmesg");
619 exit(1);
620 }
621 close(pipefds[1]);
622 fp = fdopen(pipefds[0], "r");
623 if (!fp) {
624 ksft_perror("fdopen(pipe)");
625 kill(pid, SIGTERM);
626
627 return -1;
628 }
629
630 while (fgets(line, 1024, fp)) {
631 if (strstr(line, "intel_rdt:"))
632 ksft_print_msg("dmesg: %s", line);
633 if (strstr(line, "resctrl:"))
634 ksft_print_msg("dmesg: %s", line);
635 }
636 fclose(fp);
637 waitpid(pid, NULL, 0);
638
639 return 0;
640 }
641
validate_bw_report_request(char * bw_report)642 int validate_bw_report_request(char *bw_report)
643 {
644 if (strcmp(bw_report, "reads") == 0)
645 return 0;
646 if (strcmp(bw_report, "writes") == 0)
647 return 0;
648 if (strcmp(bw_report, "nt-writes") == 0) {
649 strcpy(bw_report, "writes");
650 return 0;
651 }
652 if (strcmp(bw_report, "total") == 0)
653 return 0;
654
655 fprintf(stderr, "Requested iMC B/W report type unavailable\n");
656
657 return -1;
658 }
659
perf_event_open(struct perf_event_attr * hw_event,pid_t pid,int cpu,int group_fd,unsigned long flags)660 int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
661 int group_fd, unsigned long flags)
662 {
663 int ret;
664
665 ret = syscall(__NR_perf_event_open, hw_event, pid, cpu,
666 group_fd, flags);
667 return ret;
668 }
669
count_bits(unsigned long n)670 unsigned int count_bits(unsigned long n)
671 {
672 unsigned int count = 0;
673
674 while (n) {
675 count += n & 1;
676 n >>= 1;
677 }
678
679 return count;
680 }
681