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 <fcntl.h>
12#include <limits.h>
13
14#include "resctrl.h"
15
16static int find_resctrl_mount(char *buffer)
17{
18 FILE *mounts;
19 char line[256], *fs, *mntpoint;
20
21 mounts = fopen("/proc/mounts", "r");
22 if (!mounts) {
23 ksft_perror(msg: "/proc/mounts");
24 return -ENXIO;
25 }
26 while (!feof(mounts)) {
27 if (!fgets(line, 256, mounts))
28 break;
29 fs = strtok(line, " \t");
30 if (!fs)
31 continue;
32 mntpoint = strtok(NULL, " \t");
33 if (!mntpoint)
34 continue;
35 fs = strtok(NULL, " \t");
36 if (!fs)
37 continue;
38 if (strcmp(fs, "resctrl"))
39 continue;
40
41 fclose(mounts);
42 if (buffer)
43 strncpy(p: buffer, q: mntpoint, size: 256);
44
45 return 0;
46 }
47
48 fclose(mounts);
49
50 return -ENOENT;
51}
52
53/*
54 * mount_resctrlfs - Mount resctrl FS at /sys/fs/resctrl
55 *
56 * Mounts resctrl FS. Fails if resctrl FS is already mounted to avoid
57 * pre-existing settings interfering with the test results.
58 *
59 * Return: 0 on success, < 0 on error.
60 */
61int mount_resctrlfs(void)
62{
63 int ret;
64
65 ret = find_resctrl_mount(NULL);
66 if (ret != -ENOENT)
67 return -1;
68
69 ksft_print_msg(msg: "Mounting resctrl to \"%s\"\n", RESCTRL_PATH);
70 ret = mount("resctrl", RESCTRL_PATH, "resctrl", 0, NULL);
71 if (ret)
72 ksft_perror(msg: "mount");
73
74 return ret;
75}
76
77int umount_resctrlfs(void)
78{
79 char mountpoint[256];
80 int ret;
81
82 ret = find_resctrl_mount(buffer: mountpoint);
83 if (ret == -ENOENT)
84 return 0;
85 if (ret)
86 return ret;
87
88 if (umount(mountpoint)) {
89 ksft_perror(msg: "Unable to umount resctrl");
90
91 return -1;
92 }
93
94 return 0;
95}
96
97/*
98 * get_cache_level - Convert cache level from string to integer
99 * @cache_type: Cache level as string
100 *
101 * Return: cache level as integer or -1 if @cache_type is invalid.
102 */
103static int get_cache_level(const char *cache_type)
104{
105 if (!strcmp(cache_type, "L3"))
106 return 3;
107 if (!strcmp(cache_type, "L2"))
108 return 2;
109
110 ksft_print_msg(msg: "Invalid cache level\n");
111 return -1;
112}
113
114static int get_resource_cache_level(const char *resource)
115{
116 /* "MB" use L3 (LLC) as resource */
117 if (!strcmp(resource, "MB"))
118 return 3;
119 return get_cache_level(cache_type: resource);
120}
121
122/*
123 * get_domain_id - Get resctrl domain ID for a specified CPU
124 * @resource: resource name
125 * @cpu_no: CPU number
126 * @domain_id: domain ID (cache ID; for MB, L3 cache ID)
127 *
128 * Return: >= 0 on success, < 0 on failure.
129 */
130int get_domain_id(const char *resource, int cpu_no, int *domain_id)
131{
132 char phys_pkg_path[1024];
133 int cache_num;
134 FILE *fp;
135
136 cache_num = get_resource_cache_level(resource);
137 if (cache_num < 0)
138 return cache_num;
139
140 sprintf(buf: phys_pkg_path, fmt: "%s%d/cache/index%d/id", PHYS_ID_PATH, cpu_no, cache_num);
141
142 fp = fopen(phys_pkg_path, "r");
143 if (!fp) {
144 ksft_perror(msg: "Failed to open cache id file");
145
146 return -1;
147 }
148 if (fscanf(fp, "%d", domain_id) <= 0) {
149 ksft_perror(msg: "Could not get domain ID");
150 fclose(fp);
151
152 return -1;
153 }
154 fclose(fp);
155
156 return 0;
157}
158
159/*
160 * get_cache_size - Get cache size for a specified CPU
161 * @cpu_no: CPU number
162 * @cache_type: Cache level L2/L3
163 * @cache_size: pointer to cache_size
164 *
165 * Return: = 0 on success, < 0 on failure.
166 */
167int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size)
168{
169 char cache_path[1024], cache_str[64];
170 int length, i, cache_num;
171 FILE *fp;
172
173 cache_num = get_cache_level(cache_type);
174 if (cache_num < 0)
175 return cache_num;
176
177 sprintf(buf: cache_path, fmt: "/sys/bus/cpu/devices/cpu%d/cache/index%d/size",
178 cpu_no, cache_num);
179 fp = fopen(cache_path, "r");
180 if (!fp) {
181 ksft_perror(msg: "Failed to open cache size");
182
183 return -1;
184 }
185 if (fscanf(fp, "%s", cache_str) <= 0) {
186 ksft_perror(msg: "Could not get cache_size");
187 fclose(fp);
188
189 return -1;
190 }
191 fclose(fp);
192
193 length = (int)strlen(cache_str);
194
195 *cache_size = 0;
196
197 for (i = 0; i < length; i++) {
198 if ((cache_str[i] >= '0') && (cache_str[i] <= '9'))
199
200 *cache_size = *cache_size * 10 + (cache_str[i] - '0');
201
202 else if (cache_str[i] == 'K')
203
204 *cache_size = *cache_size * 1024;
205
206 else if (cache_str[i] == 'M')
207
208 *cache_size = *cache_size * 1024 * 1024;
209
210 else
211 break;
212 }
213
214 return 0;
215}
216
217#define CORE_SIBLINGS_PATH "/sys/bus/cpu/devices/cpu"
218
219/*
220 * get_bit_mask - Get bit mask from given file
221 * @filename: File containing the mask
222 * @mask: The bit mask returned as unsigned long
223 *
224 * Return: = 0 on success, < 0 on failure.
225 */
226static int get_bit_mask(const char *filename, unsigned long *mask)
227{
228 FILE *fp;
229
230 if (!filename || !mask)
231 return -1;
232
233 fp = fopen(filename, "r");
234 if (!fp) {
235 ksft_print_msg(msg: "Failed to open bit mask file '%s': %s\n",
236 filename, strerror(errno));
237 return -1;
238 }
239
240 if (fscanf(fp, "%lx", mask) <= 0) {
241 ksft_print_msg(msg: "Could not read bit mask file '%s': %s\n",
242 filename, strerror(errno));
243 fclose(fp);
244
245 return -1;
246 }
247 fclose(fp);
248
249 return 0;
250}
251
252/*
253 * resource_info_unsigned_get - Read an unsigned value from
254 * /sys/fs/resctrl/info/@resource/@filename
255 * @resource: Resource name that matches directory name in
256 * /sys/fs/resctrl/info
257 * @filename: File in /sys/fs/resctrl/info/@resource
258 * @val: Contains read value on success.
259 *
260 * Return: = 0 on success, < 0 on failure. On success the read
261 * value is saved into @val.
262 */
263int resource_info_unsigned_get(const char *resource, const char *filename,
264 unsigned int *val)
265{
266 char file_path[PATH_MAX];
267 FILE *fp;
268
269 snprintf(buf: file_path, size: sizeof(file_path), fmt: "%s/%s/%s", INFO_PATH, resource,
270 filename);
271
272 fp = fopen(file_path, "r");
273 if (!fp) {
274 ksft_print_msg(msg: "Error opening %s: %m\n", file_path);
275 return -1;
276 }
277
278 if (fscanf(fp, "%u", val) <= 0) {
279 ksft_print_msg(msg: "Could not get contents of %s: %m\n", file_path);
280 fclose(fp);
281 return -1;
282 }
283
284 fclose(fp);
285 return 0;
286}
287
288/*
289 * create_bit_mask- Create bit mask from start, len pair
290 * @start: LSB of the mask
291 * @len Number of bits in the mask
292 */
293unsigned long create_bit_mask(unsigned int start, unsigned int len)
294{
295 return ((1UL << len) - 1UL) << start;
296}
297
298/*
299 * count_contiguous_bits - Returns the longest train of bits in a bit mask
300 * @val A bit mask
301 * @start The location of the least-significant bit of the longest train
302 *
303 * Return: The length of the contiguous bits in the longest train of bits
304 */
305unsigned int count_contiguous_bits(unsigned long val, unsigned int *start)
306{
307 unsigned long last_val;
308 unsigned int count = 0;
309
310 while (val) {
311 last_val = val;
312 val &= (val >> 1);
313 count++;
314 }
315
316 if (start) {
317 if (count)
318 *start = ffsl(last_val) - 1;
319 else
320 *start = 0;
321 }
322
323 return count;
324}
325
326/*
327 * get_full_cbm - Get full Cache Bit Mask (CBM)
328 * @cache_type: Cache type as "L2" or "L3"
329 * @mask: Full cache bit mask representing the maximal portion of cache
330 * available for allocation, returned as unsigned long.
331 *
332 * Return: = 0 on success, < 0 on failure.
333 */
334int get_full_cbm(const char *cache_type, unsigned long *mask)
335{
336 char cbm_path[PATH_MAX];
337 int ret;
338
339 if (!cache_type)
340 return -1;
341
342 snprintf(buf: cbm_path, size: sizeof(cbm_path), fmt: "%s/%s/cbm_mask",
343 INFO_PATH, cache_type);
344
345 ret = get_bit_mask(filename: cbm_path, mask);
346 if (ret || !*mask)
347 return -1;
348
349 return 0;
350}
351
352/*
353 * get_shareable_mask - Get shareable mask from shareable_bits
354 * @cache_type: Cache type as "L2" or "L3"
355 * @shareable_mask: Shareable mask returned as unsigned long
356 *
357 * Return: = 0 on success, < 0 on failure.
358 */
359static int get_shareable_mask(const char *cache_type, unsigned long *shareable_mask)
360{
361 char mask_path[PATH_MAX];
362
363 if (!cache_type)
364 return -1;
365
366 snprintf(buf: mask_path, size: sizeof(mask_path), fmt: "%s/%s/shareable_bits",
367 INFO_PATH, cache_type);
368
369 return get_bit_mask(filename: mask_path, mask: shareable_mask);
370}
371
372/*
373 * get_mask_no_shareable - Get Cache Bit Mask (CBM) without shareable bits
374 * @cache_type: Cache type as "L2" or "L3"
375 * @mask: The largest exclusive portion of the cache out of the
376 * full CBM, returned as unsigned long
377 *
378 * Parts of a cache may be shared with other devices such as GPU. This function
379 * calculates the largest exclusive portion of the cache where no other devices
380 * besides CPU have access to the cache portion.
381 *
382 * Return: = 0 on success, < 0 on failure.
383 */
384int get_mask_no_shareable(const char *cache_type, unsigned long *mask)
385{
386 unsigned long full_mask, shareable_mask;
387 unsigned int start, len;
388
389 if (get_full_cbm(cache_type, mask: &full_mask) < 0)
390 return -1;
391 if (get_shareable_mask(cache_type, shareable_mask: &shareable_mask) < 0)
392 return -1;
393
394 len = count_contiguous_bits(val: full_mask & ~shareable_mask, start: &start);
395 if (!len)
396 return -1;
397
398 *mask = create_bit_mask(start, len);
399
400 return 0;
401}
402
403/*
404 * taskset_benchmark - Taskset PID (i.e. benchmark) to a specified cpu
405 * @bm_pid: PID that should be binded
406 * @cpu_no: CPU number at which the PID would be binded
407 * @old_affinity: When not NULL, set to old CPU affinity
408 *
409 * Return: 0 on success, < 0 on error.
410 */
411int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity)
412{
413 cpu_set_t my_set;
414
415 if (old_affinity) {
416 CPU_ZERO(old_affinity);
417 if (sched_getaffinity(pid: bm_pid, mask: sizeof(*old_affinity),
418 old_affinity)) {
419 ksft_perror(msg: "Unable to read CPU affinity");
420 return -1;
421 }
422 }
423
424 CPU_ZERO(&my_set);
425 CPU_SET(cpu_no, &my_set);
426
427 if (sched_setaffinity(bm_pid, sizeof(cpu_set_t), &my_set)) {
428 ksft_perror(msg: "Unable to taskset benchmark");
429
430 return -1;
431 }
432
433 return 0;
434}
435
436/*
437 * taskset_restore - Taskset PID to the earlier CPU affinity
438 * @bm_pid: PID that should be reset
439 * @old_affinity: The old CPU affinity to restore
440 *
441 * Return: 0 on success, < 0 on error.
442 */
443int taskset_restore(pid_t bm_pid, cpu_set_t *old_affinity)
444{
445 if (sched_setaffinity(pid: bm_pid, new_mask: sizeof(*old_affinity), old_affinity)) {
446 ksft_perror(msg: "Unable to restore CPU affinity");
447 return -1;
448 }
449
450 return 0;
451}
452
453/*
454 * create_grp - Create a group only if one doesn't exist
455 * @grp_name: Name of the group
456 * @grp: Full path and name of the group
457 * @parent_grp: Full path and name of the parent group
458 *
459 * Return: 0 on success, < 0 on error.
460 */
461static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
462{
463 int found_grp = 0;
464 struct dirent *ep;
465 DIR *dp;
466
467 /*
468 * At this point, we are guaranteed to have resctrl FS mounted and if
469 * length of grp_name == 0, it means, user wants to use root con_mon
470 * grp, so do nothing
471 */
472 if (strlen(grp_name) == 0)
473 return 0;
474
475 /* Check if requested grp exists or not */
476 dp = opendir(parent_grp);
477 if (dp) {
478 while ((ep = readdir(dp)) != NULL) {
479 if (strcmp(ep->d_name, grp_name) == 0)
480 found_grp = 1;
481 }
482 closedir(dp);
483 } else {
484 ksft_perror(msg: "Unable to open resctrl for group");
485
486 return -1;
487 }
488
489 /* Requested grp doesn't exist, hence create it */
490 if (found_grp == 0) {
491 if (mkdir(grp, 0) == -1) {
492 ksft_perror(msg: "Unable to create group");
493
494 return -1;
495 }
496 }
497
498 return 0;
499}
500
501static int write_pid_to_tasks(char *tasks, pid_t pid)
502{
503 FILE *fp;
504
505 fp = fopen(tasks, "w");
506 if (!fp) {
507 ksft_perror(msg: "Failed to open tasks file");
508
509 return -1;
510 }
511 if (fprintf(fp, "%d\n", pid) < 0) {
512 ksft_print_msg(msg: "Failed to write pid to tasks file\n");
513 fclose(fp);
514
515 return -1;
516 }
517 fclose(fp);
518
519 return 0;
520}
521
522/*
523 * write_bm_pid_to_resctrl - Write a PID (i.e. benchmark) to resctrl FS
524 * @bm_pid: PID that should be written
525 * @ctrlgrp: Name of the control monitor group (con_mon grp)
526 * @mongrp: Name of the monitor group (mon grp)
527 * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc)
528 *
529 * If a con_mon grp is requested, create it and write pid to it, otherwise
530 * write pid to root con_mon grp.
531 * If a mon grp is requested, create it and write pid to it, otherwise
532 * pid is not written, this means that pid is in con_mon grp and hence
533 * should consult con_mon grp's mon_data directory for results.
534 *
535 * Return: 0 on success, < 0 on error.
536 */
537int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
538 char *resctrl_val)
539{
540 char controlgroup[128], monitorgroup[512], monitorgroup_p[256];
541 char tasks[1024];
542 int ret = 0;
543
544 if (strlen(ctrlgrp))
545 sprintf(buf: controlgroup, fmt: "%s/%s", RESCTRL_PATH, ctrlgrp);
546 else
547 sprintf(buf: controlgroup, fmt: "%s", RESCTRL_PATH);
548
549 /* Create control and monitoring group and write pid into it */
550 ret = create_grp(grp_name: ctrlgrp, grp: controlgroup, RESCTRL_PATH);
551 if (ret)
552 goto out;
553 sprintf(buf: tasks, fmt: "%s/tasks", controlgroup);
554 ret = write_pid_to_tasks(tasks, pid: bm_pid);
555 if (ret)
556 goto out;
557
558 /* Create mon grp and write pid into it for "mbm" and "cmt" test */
559 if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)) ||
560 !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
561 if (strlen(mongrp)) {
562 sprintf(buf: monitorgroup_p, fmt: "%s/mon_groups", controlgroup);
563 sprintf(buf: monitorgroup, fmt: "%s/%s", monitorgroup_p, mongrp);
564 ret = create_grp(grp_name: mongrp, grp: monitorgroup, parent_grp: monitorgroup_p);
565 if (ret)
566 goto out;
567
568 sprintf(buf: tasks, fmt: "%s/mon_groups/%s/tasks",
569 controlgroup, mongrp);
570 ret = write_pid_to_tasks(tasks, pid: bm_pid);
571 if (ret)
572 goto out;
573 }
574 }
575
576out:
577 ksft_print_msg(msg: "Writing benchmark parameters to resctrl FS\n");
578 if (ret)
579 ksft_print_msg(msg: "Failed writing to resctrlfs\n");
580
581 return ret;
582}
583
584/*
585 * write_schemata - Update schemata of a con_mon grp
586 * @ctrlgrp: Name of the con_mon grp
587 * @schemata: Schemata that should be updated to
588 * @cpu_no: CPU number that the benchmark PID is binded to
589 * @resource: Resctrl resource (Eg: MB, L3, L2, etc.)
590 *
591 * Update schemata of a con_mon grp *only* if requested resctrl resource is
592 * allocation type
593 *
594 * Return: 0 on success, < 0 on error.
595 */
596int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, const char *resource)
597{
598 char controlgroup[1024], reason[128], schema[1024] = {};
599 int domain_id, fd, schema_len, ret = 0;
600
601 if (!schemata) {
602 ksft_print_msg(msg: "Skipping empty schemata update\n");
603
604 return -1;
605 }
606
607 if (get_domain_id(resource, cpu_no, domain_id: &domain_id) < 0) {
608 sprintf(buf: reason, fmt: "Failed to get domain ID");
609 ret = -1;
610
611 goto out;
612 }
613
614 if (strlen(ctrlgrp) != 0)
615 sprintf(buf: controlgroup, fmt: "%s/%s/schemata", RESCTRL_PATH, ctrlgrp);
616 else
617 sprintf(buf: controlgroup, fmt: "%s/schemata", RESCTRL_PATH);
618
619 schema_len = snprintf(buf: schema, size: sizeof(schema), fmt: "%s:%d=%s\n",
620 resource, domain_id, schemata);
621 if (schema_len < 0 || schema_len >= sizeof(schema)) {
622 snprintf(buf: reason, size: sizeof(reason),
623 fmt: "snprintf() failed with return value : %d", schema_len);
624 ret = -1;
625 goto out;
626 }
627
628 fd = open(controlgroup, O_WRONLY);
629 if (fd < 0) {
630 snprintf(reason, sizeof(reason),
631 "open() failed : %s", strerror(errno));
632 ret = -1;
633
634 goto err_schema_not_empty;
635 }
636 if (write(fd, schema, schema_len) < 0) {
637 snprintf(reason, sizeof(reason),
638 "write() failed : %s", strerror(errno));
639 close(fd);
640 ret = -1;
641
642 goto err_schema_not_empty;
643 }
644 close(fd);
645
646err_schema_not_empty:
647 schema[schema_len - 1] = 0;
648out:
649 ksft_print_msg(msg: "Write schema \"%s\" to resctrl FS%s%s\n",
650 schema, ret ? " # " : "",
651 ret ? reason : "");
652
653 return ret;
654}
655
656bool check_resctrlfs_support(void)
657{
658 FILE *inf = fopen("/proc/filesystems", "r");
659 DIR *dp;
660 char *res;
661 bool ret = false;
662
663 if (!inf)
664 return false;
665
666 res = fgrep(inf, "nodev\tresctrl\n");
667
668 if (res) {
669 ret = true;
670 free(res);
671 }
672
673 fclose(inf);
674
675 ksft_print_msg(msg: "%s Check kernel supports resctrl filesystem\n",
676 ret ? "Pass:" : "Fail:");
677
678 if (!ret)
679 return ret;
680
681 dp = opendir(RESCTRL_PATH);
682 ksft_print_msg("%s Check resctrl mountpoint \"%s\" exists\n",
683 dp ? "Pass:" : "Fail:", RESCTRL_PATH);
684 if (dp)
685 closedir(dp);
686
687 ksft_print_msg(msg: "resctrl filesystem %s mounted\n",
688 find_resctrl_mount(NULL) ? "not" : "is");
689
690 return ret;
691}
692
693char *fgrep(FILE *inf, const char *str)
694{
695 char line[256];
696 int slen = strlen(str);
697
698 while (!feof(inf)) {
699 if (!fgets(line, 256, inf))
700 break;
701 if (strncmp(line, str, slen))
702 continue;
703
704 return strdup(line);
705 }
706
707 return NULL;
708}
709
710/*
711 * resctrl_resource_exists - Check if a resource is supported.
712 * @resource: Resctrl resource (e.g., MB, L3, L2, L3_MON, etc.)
713 *
714 * Return: True if the resource is supported, else false. False is
715 * also returned if resctrl FS is not mounted.
716 */
717bool resctrl_resource_exists(const char *resource)
718{
719 char res_path[PATH_MAX];
720 struct stat statbuf;
721 int ret;
722
723 if (!resource)
724 return false;
725
726 ret = find_resctrl_mount(NULL);
727 if (ret)
728 return false;
729
730 snprintf(buf: res_path, size: sizeof(res_path), fmt: "%s/%s", INFO_PATH, resource);
731
732 if (stat(res_path, &statbuf))
733 return false;
734
735 return true;
736}
737
738/*
739 * resctrl_mon_feature_exists - Check if requested monitoring feature is valid.
740 * @resource: Resource that uses the mon_features file. Currently only L3_MON
741 * is valid.
742 * @feature: Required monitor feature (in mon_features file).
743 *
744 * Return: True if the feature is supported, else false.
745 */
746bool resctrl_mon_feature_exists(const char *resource, const char *feature)
747{
748 char res_path[PATH_MAX];
749 char *res;
750 FILE *inf;
751
752 if (!feature || !resource)
753 return false;
754
755 snprintf(buf: res_path, size: sizeof(res_path), fmt: "%s/%s/mon_features", INFO_PATH, resource);
756 inf = fopen(res_path, "r");
757 if (!inf)
758 return false;
759
760 res = fgrep(inf, feature);
761 free(res);
762 fclose(inf);
763
764 return !!res;
765}
766
767/*
768 * resource_info_file_exists - Check if a file is present inside
769 * /sys/fs/resctrl/info/@resource.
770 * @resource: Required resource (Eg: MB, L3, L2, etc.)
771 * @file: Required file.
772 *
773 * Return: True if the /sys/fs/resctrl/info/@resource/@file exists, else false.
774 */
775bool resource_info_file_exists(const char *resource, const char *file)
776{
777 char res_path[PATH_MAX];
778 struct stat statbuf;
779
780 if (!file || !resource)
781 return false;
782
783 snprintf(buf: res_path, size: sizeof(res_path), fmt: "%s/%s/%s", INFO_PATH, resource,
784 file);
785
786 if (stat(res_path, &statbuf))
787 return false;
788
789 return true;
790}
791
792bool test_resource_feature_check(const struct resctrl_test *test)
793{
794 return resctrl_resource_exists(resource: test->resource);
795}
796
797int filter_dmesg(void)
798{
799 char line[1024];
800 FILE *fp;
801 int pipefds[2];
802 pid_t pid;
803 int ret;
804
805 ret = pipe(pipefds);
806 if (ret) {
807 ksft_perror(msg: "pipe");
808 return ret;
809 }
810 fflush(stdout);
811 pid = fork();
812 if (pid == 0) {
813 close(pipefds[0]);
814 dup2(pipefds[1], STDOUT_FILENO);
815 execlp("dmesg", "dmesg", NULL);
816 ksft_perror(msg: "Executing dmesg");
817 exit(1);
818 }
819 close(pipefds[1]);
820 fp = fdopen(pipefds[0], "r");
821 if (!fp) {
822 ksft_perror(msg: "fdopen(pipe)");
823 kill(pid, SIGTERM);
824
825 return -1;
826 }
827
828 while (fgets(line, 1024, fp)) {
829 if (strstr(line, "intel_rdt:"))
830 ksft_print_msg(msg: "dmesg: %s", line);
831 if (strstr(line, "resctrl:"))
832 ksft_print_msg(msg: "dmesg: %s", line);
833 }
834 fclose(fp);
835 waitpid(pid, NULL, 0);
836
837 return 0;
838}
839
840int validate_bw_report_request(char *bw_report)
841{
842 if (strcmp(bw_report, "reads") == 0)
843 return 0;
844 if (strcmp(bw_report, "writes") == 0)
845 return 0;
846 if (strcmp(bw_report, "nt-writes") == 0) {
847 strcpy(p: bw_report, q: "writes");
848 return 0;
849 }
850 if (strcmp(bw_report, "total") == 0)
851 return 0;
852
853 fprintf(stderr, "Requested iMC B/W report type unavailable\n");
854
855 return -1;
856}
857
858int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
859 int group_fd, unsigned long flags)
860{
861 int ret;
862
863 ret = syscall(__NR_perf_event_open, hw_event, pid, cpu,
864 group_fd, flags);
865 return ret;
866}
867
868unsigned int count_bits(unsigned long n)
869{
870 unsigned int count = 0;
871
872 while (n) {
873 count += n & 1;
874 n >>= 1;
875 }
876
877 return count;
878}
879

source code of linux/tools/testing/selftests/resctrl/resctrlfs.c