xref: /linux/tools/tracing/rtla/src/osnoise_hist.c (revision f5c31bcf604db54470868f3118a60dc4a9ba8813)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
4  */
5 
6 #define _GNU_SOURCE
7 #include <getopt.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <signal.h>
11 #include <unistd.h>
12 #include <errno.h>
13 #include <stdio.h>
14 #include <time.h>
15 #include <sched.h>
16 
17 #include "utils.h"
18 #include "osnoise.h"
19 
20 struct osnoise_hist_params {
21 	char			*cpus;
22 	cpu_set_t		monitored_cpus;
23 	char			*trace_output;
24 	char			*cgroup_name;
25 	unsigned long long	runtime;
26 	unsigned long long	period;
27 	long long		threshold;
28 	long long		stop_us;
29 	long long		stop_total_us;
30 	int			sleep_time;
31 	int			duration;
32 	int			set_sched;
33 	int			output_divisor;
34 	int			cgroup;
35 	int			hk_cpus;
36 	cpu_set_t		hk_cpu_set;
37 	struct sched_attr	sched_param;
38 	struct trace_events	*events;
39 
40 	char			no_header;
41 	char			no_summary;
42 	char			no_index;
43 	char			with_zeros;
44 	int			bucket_size;
45 	int			entries;
46 };
47 
48 struct osnoise_hist_cpu {
49 	int			*samples;
50 	int			count;
51 
52 	unsigned long long	min_sample;
53 	unsigned long long	sum_sample;
54 	unsigned long long	max_sample;
55 
56 };
57 
58 struct osnoise_hist_data {
59 	struct tracefs_hist	*trace_hist;
60 	struct osnoise_hist_cpu	*hist;
61 	int			entries;
62 	int			bucket_size;
63 	int			nr_cpus;
64 };
65 
66 /*
67  * osnoise_free_histogram - free runtime data
68  */
69 static void
70 osnoise_free_histogram(struct osnoise_hist_data *data)
71 {
72 	int cpu;
73 
74 	/* one histogram for IRQ and one for thread, per CPU */
75 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
76 		if (data->hist[cpu].samples)
77 			free(data->hist[cpu].samples);
78 	}
79 
80 	/* one set of histograms per CPU */
81 	if (data->hist)
82 		free(data->hist);
83 
84 	free(data);
85 }
86 
87 /*
88  * osnoise_alloc_histogram - alloc runtime data
89  */
90 static struct osnoise_hist_data
91 *osnoise_alloc_histogram(int nr_cpus, int entries, int bucket_size)
92 {
93 	struct osnoise_hist_data *data;
94 	int cpu;
95 
96 	data = calloc(1, sizeof(*data));
97 	if (!data)
98 		return NULL;
99 
100 	data->entries = entries;
101 	data->bucket_size = bucket_size;
102 	data->nr_cpus = nr_cpus;
103 
104 	data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
105 	if (!data->hist)
106 		goto cleanup;
107 
108 	for (cpu = 0; cpu < nr_cpus; cpu++) {
109 		data->hist[cpu].samples = calloc(1, sizeof(*data->hist->samples) * (entries + 1));
110 		if (!data->hist[cpu].samples)
111 			goto cleanup;
112 	}
113 
114 	/* set the min to max */
115 	for (cpu = 0; cpu < nr_cpus; cpu++)
116 		data->hist[cpu].min_sample = ~0;
117 
118 	return data;
119 
120 cleanup:
121 	osnoise_free_histogram(data);
122 	return NULL;
123 }
124 
125 static void osnoise_hist_update_multiple(struct osnoise_tool *tool, int cpu,
126 					 unsigned long long duration, int count)
127 {
128 	struct osnoise_hist_params *params = tool->params;
129 	struct osnoise_hist_data *data = tool->data;
130 	unsigned long long total_duration;
131 	int entries = data->entries;
132 	int bucket;
133 	int *hist;
134 
135 	if (params->output_divisor)
136 		duration = duration / params->output_divisor;
137 
138 	bucket = duration / data->bucket_size;
139 
140 	total_duration = duration * count;
141 
142 	hist = data->hist[cpu].samples;
143 	data->hist[cpu].count += count;
144 	update_min(&data->hist[cpu].min_sample, &duration);
145 	update_sum(&data->hist[cpu].sum_sample, &total_duration);
146 	update_max(&data->hist[cpu].max_sample, &duration);
147 
148 	if (bucket < entries)
149 		hist[bucket] += count;
150 	else
151 		hist[entries] += count;
152 }
153 
154 /*
155  * osnoise_destroy_trace_hist - disable events used to collect histogram
156  */
157 static void osnoise_destroy_trace_hist(struct osnoise_tool *tool)
158 {
159 	struct osnoise_hist_data *data = tool->data;
160 
161 	tracefs_hist_pause(tool->trace.inst, data->trace_hist);
162 	tracefs_hist_destroy(tool->trace.inst, data->trace_hist);
163 }
164 
165 /*
166  * osnoise_init_trace_hist - enable events used to collect histogram
167  */
168 static int osnoise_init_trace_hist(struct osnoise_tool *tool)
169 {
170 	struct osnoise_hist_params *params = tool->params;
171 	struct osnoise_hist_data *data = tool->data;
172 	int bucket_size;
173 	char buff[128];
174 	int retval = 0;
175 
176 	/*
177 	 * Set the size of the bucket.
178 	 */
179 	bucket_size = params->output_divisor * params->bucket_size;
180 	snprintf(buff, sizeof(buff), "duration.buckets=%d", bucket_size);
181 
182 	data->trace_hist = tracefs_hist_alloc(tool->trace.tep, "osnoise", "sample_threshold",
183 			buff, TRACEFS_HIST_KEY_NORMAL);
184 	if (!data->trace_hist)
185 		return 1;
186 
187 	retval = tracefs_hist_add_key(data->trace_hist, "cpu", 0);
188 	if (retval)
189 		goto out_err;
190 
191 	retval = tracefs_hist_start(tool->trace.inst, data->trace_hist);
192 	if (retval)
193 		goto out_err;
194 
195 	return 0;
196 
197 out_err:
198 	osnoise_destroy_trace_hist(tool);
199 	return 1;
200 }
201 
202 /*
203  * osnoise_read_trace_hist - parse histogram file and file osnoise histogram
204  */
205 static void osnoise_read_trace_hist(struct osnoise_tool *tool)
206 {
207 	struct osnoise_hist_data *data = tool->data;
208 	long long cpu, counter, duration;
209 	char *content, *position;
210 
211 	tracefs_hist_pause(tool->trace.inst, data->trace_hist);
212 
213 	content = tracefs_event_file_read(tool->trace.inst, "osnoise",
214 					  "sample_threshold",
215 					  "hist", NULL);
216 	if (!content)
217 		return;
218 
219 	position = content;
220 	while (true) {
221 		position = strstr(position, "duration: ~");
222 		if (!position)
223 			break;
224 		position += strlen("duration: ~");
225 		duration = get_llong_from_str(position);
226 		if (duration == -1)
227 			err_msg("error reading duration from histogram\n");
228 
229 		position = strstr(position, "cpu:");
230 		if (!position)
231 			break;
232 		position += strlen("cpu: ");
233 		cpu = get_llong_from_str(position);
234 		if (cpu == -1)
235 			err_msg("error reading cpu from histogram\n");
236 
237 		position = strstr(position, "hitcount:");
238 		if (!position)
239 			break;
240 		position += strlen("hitcount: ");
241 		counter = get_llong_from_str(position);
242 		if (counter == -1)
243 			err_msg("error reading counter from histogram\n");
244 
245 		osnoise_hist_update_multiple(tool, cpu, duration, counter);
246 	}
247 	free(content);
248 }
249 
250 /*
251  * osnoise_hist_header - print the header of the tracer to the output
252  */
253 static void osnoise_hist_header(struct osnoise_tool *tool)
254 {
255 	struct osnoise_hist_params *params = tool->params;
256 	struct osnoise_hist_data *data = tool->data;
257 	struct trace_seq *s = tool->trace.seq;
258 	char duration[26];
259 	int cpu;
260 
261 	if (params->no_header)
262 		return;
263 
264 	get_duration(tool->start_time, duration, sizeof(duration));
265 	trace_seq_printf(s, "# RTLA osnoise histogram\n");
266 	trace_seq_printf(s, "# Time unit is %s (%s)\n",
267 			params->output_divisor == 1 ? "nanoseconds" : "microseconds",
268 			params->output_divisor == 1 ? "ns" : "us");
269 
270 	trace_seq_printf(s, "# Duration: %s\n", duration);
271 
272 	if (!params->no_index)
273 		trace_seq_printf(s, "Index");
274 
275 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
276 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
277 			continue;
278 
279 		if (!data->hist[cpu].count)
280 			continue;
281 
282 		trace_seq_printf(s, "   CPU-%03d", cpu);
283 	}
284 	trace_seq_printf(s, "\n");
285 
286 	trace_seq_do_printf(s);
287 	trace_seq_reset(s);
288 }
289 
290 /*
291  * osnoise_print_summary - print the summary of the hist data to the output
292  */
293 static void
294 osnoise_print_summary(struct osnoise_hist_params *params,
295 		       struct trace_instance *trace,
296 		       struct osnoise_hist_data *data)
297 {
298 	int cpu;
299 
300 	if (params->no_summary)
301 		return;
302 
303 	if (!params->no_index)
304 		trace_seq_printf(trace->seq, "count:");
305 
306 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
307 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
308 			continue;
309 
310 		if (!data->hist[cpu].count)
311 			continue;
312 
313 		trace_seq_printf(trace->seq, "%9d ", data->hist[cpu].count);
314 	}
315 	trace_seq_printf(trace->seq, "\n");
316 
317 	if (!params->no_index)
318 		trace_seq_printf(trace->seq, "min:  ");
319 
320 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
321 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
322 			continue;
323 
324 		if (!data->hist[cpu].count)
325 			continue;
326 
327 		trace_seq_printf(trace->seq, "%9llu ",	data->hist[cpu].min_sample);
328 
329 	}
330 	trace_seq_printf(trace->seq, "\n");
331 
332 	if (!params->no_index)
333 		trace_seq_printf(trace->seq, "avg:  ");
334 
335 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
336 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
337 			continue;
338 
339 		if (!data->hist[cpu].count)
340 			continue;
341 
342 		if (data->hist[cpu].count)
343 			trace_seq_printf(trace->seq, "%9.2f ",
344 				((double) data->hist[cpu].sum_sample) / data->hist[cpu].count);
345 		else
346 			trace_seq_printf(trace->seq, "        - ");
347 	}
348 	trace_seq_printf(trace->seq, "\n");
349 
350 	if (!params->no_index)
351 		trace_seq_printf(trace->seq, "max:  ");
352 
353 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
354 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
355 			continue;
356 
357 		if (!data->hist[cpu].count)
358 			continue;
359 
360 		trace_seq_printf(trace->seq, "%9llu ", data->hist[cpu].max_sample);
361 
362 	}
363 	trace_seq_printf(trace->seq, "\n");
364 	trace_seq_do_printf(trace->seq);
365 	trace_seq_reset(trace->seq);
366 }
367 
368 /*
369  * osnoise_print_stats - print data for all CPUs
370  */
371 static void
372 osnoise_print_stats(struct osnoise_hist_params *params, struct osnoise_tool *tool)
373 {
374 	struct osnoise_hist_data *data = tool->data;
375 	struct trace_instance *trace = &tool->trace;
376 	int bucket, cpu;
377 	int total;
378 
379 	osnoise_hist_header(tool);
380 
381 	for (bucket = 0; bucket < data->entries; bucket++) {
382 		total = 0;
383 
384 		if (!params->no_index)
385 			trace_seq_printf(trace->seq, "%-6d",
386 					 bucket * data->bucket_size);
387 
388 		for (cpu = 0; cpu < data->nr_cpus; cpu++) {
389 			if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
390 				continue;
391 
392 			if (!data->hist[cpu].count)
393 				continue;
394 
395 			total += data->hist[cpu].samples[bucket];
396 			trace_seq_printf(trace->seq, "%9d ", data->hist[cpu].samples[bucket]);
397 		}
398 
399 		if (total == 0 && !params->with_zeros) {
400 			trace_seq_reset(trace->seq);
401 			continue;
402 		}
403 
404 		trace_seq_printf(trace->seq, "\n");
405 		trace_seq_do_printf(trace->seq);
406 		trace_seq_reset(trace->seq);
407 	}
408 
409 	if (!params->no_index)
410 		trace_seq_printf(trace->seq, "over: ");
411 
412 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
413 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
414 			continue;
415 
416 		if (!data->hist[cpu].count)
417 			continue;
418 
419 		trace_seq_printf(trace->seq, "%9d ",
420 				 data->hist[cpu].samples[data->entries]);
421 	}
422 	trace_seq_printf(trace->seq, "\n");
423 	trace_seq_do_printf(trace->seq);
424 	trace_seq_reset(trace->seq);
425 
426 	osnoise_print_summary(params, trace, data);
427 }
428 
429 /*
430  * osnoise_hist_usage - prints osnoise hist usage message
431  */
432 static void osnoise_hist_usage(char *usage)
433 {
434 	int i;
435 
436 	static const char * const msg[] = {
437 		"",
438 		"  usage: rtla osnoise hist [-h] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
439 		"	  [-T us] [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
440 		"	  [-c cpu-list] [-H cpu-list] [-P priority] [-b N] [-E N] [--no-header] [--no-summary] \\",
441 		"	  [--no-index] [--with-zeros] [-C[=cgroup_name]]",
442 		"",
443 		"	  -h/--help: print this menu",
444 		"	  -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
445 		"	  -p/--period us: osnoise period in us",
446 		"	  -r/--runtime us: osnoise runtime in us",
447 		"	  -s/--stop us: stop trace if a single sample is higher than the argument in us",
448 		"	  -S/--stop-total us: stop trace if the total sample is higher than the argument in us",
449 		"	  -T/--threshold us: the minimum delta to be considered a noise",
450 		"	  -c/--cpus cpu-list: list of cpus to run osnoise threads",
451 		"	  -H/--house-keeping cpus: run rtla control threads only on the given cpus",
452 		"	  -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
453 		"	  -d/--duration time[s|m|h|d]: duration of the session",
454 		"	  -D/--debug: print debug info",
455 		"	  -t/--trace[=file]: save the stopped trace to [file|osnoise_trace.txt]",
456 		"	  -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
457 		"	     --filter <filter>: enable a trace event filter to the previous -e event",
458 		"	     --trigger <trigger>: enable a trace event trigger to the previous -e event",
459 		"	  -b/--bucket-size N: set the histogram bucket size (default 1)",
460 		"	  -E/--entries N: set the number of entries of the histogram (default 256)",
461 		"	     --no-header: do not print header",
462 		"	     --no-summary: do not print summary",
463 		"	     --no-index: do not print index",
464 		"	     --with-zeros: print zero only entries",
465 		"	  -P/--priority o:prio|r:prio|f:prio|d:runtime:period: set scheduling parameters",
466 		"		o:prio - use SCHED_OTHER with prio",
467 		"		r:prio - use SCHED_RR with prio",
468 		"		f:prio - use SCHED_FIFO with prio",
469 		"		d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
470 		"						       in nanoseconds",
471 		NULL,
472 	};
473 
474 	if (usage)
475 		fprintf(stderr, "%s\n", usage);
476 
477 	fprintf(stderr, "rtla osnoise hist: a per-cpu histogram of the OS noise (version %s)\n",
478 			VERSION);
479 
480 	for (i = 0; msg[i]; i++)
481 		fprintf(stderr, "%s\n", msg[i]);
482 
483 	if (usage)
484 		exit(EXIT_FAILURE);
485 
486 	exit(EXIT_SUCCESS);
487 }
488 
489 /*
490  * osnoise_hist_parse_args - allocs, parse and fill the cmd line parameters
491  */
492 static struct osnoise_hist_params
493 *osnoise_hist_parse_args(int argc, char *argv[])
494 {
495 	struct osnoise_hist_params *params;
496 	struct trace_events *tevent;
497 	int retval;
498 	int c;
499 
500 	params = calloc(1, sizeof(*params));
501 	if (!params)
502 		exit(1);
503 
504 	/* display data in microseconds */
505 	params->output_divisor = 1000;
506 	params->bucket_size = 1;
507 	params->entries = 256;
508 
509 	while (1) {
510 		static struct option long_options[] = {
511 			{"auto",		required_argument,	0, 'a'},
512 			{"bucket-size",		required_argument,	0, 'b'},
513 			{"entries",		required_argument,	0, 'E'},
514 			{"cpus",		required_argument,	0, 'c'},
515 			{"cgroup",		optional_argument,	0, 'C'},
516 			{"debug",		no_argument,		0, 'D'},
517 			{"duration",		required_argument,	0, 'd'},
518 			{"house-keeping",	required_argument,		0, 'H'},
519 			{"help",		no_argument,		0, 'h'},
520 			{"period",		required_argument,	0, 'p'},
521 			{"priority",		required_argument,	0, 'P'},
522 			{"runtime",		required_argument,	0, 'r'},
523 			{"stop",		required_argument,	0, 's'},
524 			{"stop-total",		required_argument,	0, 'S'},
525 			{"trace",		optional_argument,	0, 't'},
526 			{"event",		required_argument,	0, 'e'},
527 			{"threshold",		required_argument,	0, 'T'},
528 			{"no-header",		no_argument,		0, '0'},
529 			{"no-summary",		no_argument,		0, '1'},
530 			{"no-index",		no_argument,		0, '2'},
531 			{"with-zeros",		no_argument,		0, '3'},
532 			{"trigger",		required_argument,	0, '4'},
533 			{"filter",		required_argument,	0, '5'},
534 			{0, 0, 0, 0}
535 		};
536 
537 		/* getopt_long stores the option index here. */
538 		int option_index = 0;
539 
540 		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:p:P:r:s:S:t::T:01234:5:",
541 				 long_options, &option_index);
542 
543 		/* detect the end of the options. */
544 		if (c == -1)
545 			break;
546 
547 		switch (c) {
548 		case 'a':
549 			/* set sample stop to auto_thresh */
550 			params->stop_us = get_llong_from_str(optarg);
551 
552 			/* set sample threshold to 1 */
553 			params->threshold = 1;
554 
555 			/* set trace */
556 			params->trace_output = "osnoise_trace.txt";
557 
558 			break;
559 		case 'b':
560 			params->bucket_size = get_llong_from_str(optarg);
561 			if ((params->bucket_size == 0) || (params->bucket_size >= 1000000))
562 				osnoise_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
563 			break;
564 		case 'c':
565 			retval = parse_cpu_set(optarg, &params->monitored_cpus);
566 			if (retval)
567 				osnoise_hist_usage("\nInvalid -c cpu list\n");
568 			params->cpus = optarg;
569 			break;
570 		case 'C':
571 			params->cgroup = 1;
572 			if (!optarg) {
573 				/* will inherit this cgroup */
574 				params->cgroup_name = NULL;
575 			} else if (*optarg == '=') {
576 				/* skip the = */
577 				params->cgroup_name = ++optarg;
578 			}
579 			break;
580 		case 'D':
581 			config_debug = 1;
582 			break;
583 		case 'd':
584 			params->duration = parse_seconds_duration(optarg);
585 			if (!params->duration)
586 				osnoise_hist_usage("Invalid -D duration\n");
587 			break;
588 		case 'e':
589 			tevent = trace_event_alloc(optarg);
590 			if (!tevent) {
591 				err_msg("Error alloc trace event");
592 				exit(EXIT_FAILURE);
593 			}
594 
595 			if (params->events)
596 				tevent->next = params->events;
597 
598 			params->events = tevent;
599 			break;
600 		case 'E':
601 			params->entries = get_llong_from_str(optarg);
602 			if ((params->entries < 10) || (params->entries > 9999999))
603 				osnoise_hist_usage("Entries must be > 10 and < 9999999\n");
604 			break;
605 		case 'h':
606 		case '?':
607 			osnoise_hist_usage(NULL);
608 			break;
609 		case 'H':
610 			params->hk_cpus = 1;
611 			retval = parse_cpu_set(optarg, &params->hk_cpu_set);
612 			if (retval) {
613 				err_msg("Error parsing house keeping CPUs\n");
614 				exit(EXIT_FAILURE);
615 			}
616 			break;
617 		case 'p':
618 			params->period = get_llong_from_str(optarg);
619 			if (params->period > 10000000)
620 				osnoise_hist_usage("Period longer than 10 s\n");
621 			break;
622 		case 'P':
623 			retval = parse_prio(optarg, &params->sched_param);
624 			if (retval == -1)
625 				osnoise_hist_usage("Invalid -P priority");
626 			params->set_sched = 1;
627 			break;
628 		case 'r':
629 			params->runtime = get_llong_from_str(optarg);
630 			if (params->runtime < 100)
631 				osnoise_hist_usage("Runtime shorter than 100 us\n");
632 			break;
633 		case 's':
634 			params->stop_us = get_llong_from_str(optarg);
635 			break;
636 		case 'S':
637 			params->stop_total_us = get_llong_from_str(optarg);
638 			break;
639 		case 'T':
640 			params->threshold = get_llong_from_str(optarg);
641 			break;
642 		case 't':
643 			if (optarg)
644 				/* skip = */
645 				params->trace_output = &optarg[1];
646 			else
647 				params->trace_output = "osnoise_trace.txt";
648 			break;
649 		case '0': /* no header */
650 			params->no_header = 1;
651 			break;
652 		case '1': /* no summary */
653 			params->no_summary = 1;
654 			break;
655 		case '2': /* no index */
656 			params->no_index = 1;
657 			break;
658 		case '3': /* with zeros */
659 			params->with_zeros = 1;
660 			break;
661 		case '4': /* trigger */
662 			if (params->events) {
663 				retval = trace_event_add_trigger(params->events, optarg);
664 				if (retval) {
665 					err_msg("Error adding trigger %s\n", optarg);
666 					exit(EXIT_FAILURE);
667 				}
668 			} else {
669 				osnoise_hist_usage("--trigger requires a previous -e\n");
670 			}
671 			break;
672 		case '5': /* filter */
673 			if (params->events) {
674 				retval = trace_event_add_filter(params->events, optarg);
675 				if (retval) {
676 					err_msg("Error adding filter %s\n", optarg);
677 					exit(EXIT_FAILURE);
678 				}
679 			} else {
680 				osnoise_hist_usage("--filter requires a previous -e\n");
681 			}
682 			break;
683 		default:
684 			osnoise_hist_usage("Invalid option");
685 		}
686 	}
687 
688 	if (geteuid()) {
689 		err_msg("rtla needs root permission\n");
690 		exit(EXIT_FAILURE);
691 	}
692 
693 	if (params->no_index && !params->with_zeros)
694 		osnoise_hist_usage("no-index set and with-zeros not set - it does not make sense");
695 
696 	return params;
697 }
698 
699 /*
700  * osnoise_hist_apply_config - apply the hist configs to the initialized tool
701  */
702 static int
703 osnoise_hist_apply_config(struct osnoise_tool *tool, struct osnoise_hist_params *params)
704 {
705 	int retval;
706 
707 	if (!params->sleep_time)
708 		params->sleep_time = 1;
709 
710 	if (params->cpus) {
711 		retval = osnoise_set_cpus(tool->context, params->cpus);
712 		if (retval) {
713 			err_msg("Failed to apply CPUs config\n");
714 			goto out_err;
715 		}
716 	}
717 
718 	if (params->runtime || params->period) {
719 		retval = osnoise_set_runtime_period(tool->context,
720 						    params->runtime,
721 						    params->period);
722 		if (retval) {
723 			err_msg("Failed to set runtime and/or period\n");
724 			goto out_err;
725 		}
726 	}
727 
728 	if (params->stop_us) {
729 		retval = osnoise_set_stop_us(tool->context, params->stop_us);
730 		if (retval) {
731 			err_msg("Failed to set stop us\n");
732 			goto out_err;
733 		}
734 	}
735 
736 	if (params->stop_total_us) {
737 		retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
738 		if (retval) {
739 			err_msg("Failed to set stop total us\n");
740 			goto out_err;
741 		}
742 	}
743 
744 	if (params->threshold) {
745 		retval = osnoise_set_tracing_thresh(tool->context, params->threshold);
746 		if (retval) {
747 			err_msg("Failed to set tracing_thresh\n");
748 			goto out_err;
749 		}
750 	}
751 
752 	if (params->hk_cpus) {
753 		retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
754 					   &params->hk_cpu_set);
755 		if (retval == -1) {
756 			err_msg("Failed to set rtla to the house keeping CPUs\n");
757 			goto out_err;
758 		}
759 	} else if (params->cpus) {
760 		/*
761 		 * Even if the user do not set a house-keeping CPU, try to
762 		 * move rtla to a CPU set different to the one where the user
763 		 * set the workload to run.
764 		 *
765 		 * No need to check results as this is an automatic attempt.
766 		 */
767 		auto_house_keeping(&params->monitored_cpus);
768 	}
769 
770 	return 0;
771 
772 out_err:
773 	return -1;
774 }
775 
776 /*
777  * osnoise_init_hist - initialize a osnoise hist tool with parameters
778  */
779 static struct osnoise_tool
780 *osnoise_init_hist(struct osnoise_hist_params *params)
781 {
782 	struct osnoise_tool *tool;
783 	int nr_cpus;
784 
785 	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
786 
787 	tool = osnoise_init_tool("osnoise_hist");
788 	if (!tool)
789 		return NULL;
790 
791 	tool->data = osnoise_alloc_histogram(nr_cpus, params->entries, params->bucket_size);
792 	if (!tool->data)
793 		goto out_err;
794 
795 	tool->params = params;
796 
797 	return tool;
798 
799 out_err:
800 	osnoise_destroy_tool(tool);
801 	return NULL;
802 }
803 
804 static int stop_tracing;
805 static void stop_hist(int sig)
806 {
807 	stop_tracing = 1;
808 }
809 
810 /*
811  * osnoise_hist_set_signals - handles the signal to stop the tool
812  */
813 static void
814 osnoise_hist_set_signals(struct osnoise_hist_params *params)
815 {
816 	signal(SIGINT, stop_hist);
817 	if (params->duration) {
818 		signal(SIGALRM, stop_hist);
819 		alarm(params->duration);
820 	}
821 }
822 
823 int osnoise_hist_main(int argc, char *argv[])
824 {
825 	struct osnoise_hist_params *params;
826 	struct osnoise_tool *record = NULL;
827 	struct osnoise_tool *tool = NULL;
828 	struct trace_instance *trace;
829 	int return_value = 1;
830 	int retval;
831 
832 	params = osnoise_hist_parse_args(argc, argv);
833 	if (!params)
834 		exit(1);
835 
836 	tool = osnoise_init_hist(params);
837 	if (!tool) {
838 		err_msg("Could not init osnoise hist\n");
839 		goto out_exit;
840 	}
841 
842 	retval = osnoise_hist_apply_config(tool, params);
843 	if (retval) {
844 		err_msg("Could not apply config\n");
845 		goto out_destroy;
846 	}
847 
848 	trace = &tool->trace;
849 
850 	retval = enable_osnoise(trace);
851 	if (retval) {
852 		err_msg("Failed to enable osnoise tracer\n");
853 		goto out_destroy;
854 	}
855 
856 	retval = osnoise_init_trace_hist(tool);
857 	if (retval)
858 		goto out_destroy;
859 
860 	if (params->set_sched) {
861 		retval = set_comm_sched_attr("osnoise/", &params->sched_param);
862 		if (retval) {
863 			err_msg("Failed to set sched parameters\n");
864 			goto out_free;
865 		}
866 	}
867 
868 	if (params->cgroup) {
869 		retval = set_comm_cgroup("timerlat/", params->cgroup_name);
870 		if (!retval) {
871 			err_msg("Failed to move threads to cgroup\n");
872 			goto out_free;
873 		}
874 	}
875 
876 	if (params->trace_output) {
877 		record = osnoise_init_trace_tool("osnoise");
878 		if (!record) {
879 			err_msg("Failed to enable the trace instance\n");
880 			goto out_free;
881 		}
882 
883 		if (params->events) {
884 			retval = trace_events_enable(&record->trace, params->events);
885 			if (retval)
886 				goto out_hist;
887 		}
888 
889 	}
890 
891 	/*
892 	 * Start the tracer here, after having set all instances.
893 	 *
894 	 * Let the trace instance start first for the case of hitting a stop
895 	 * tracing while enabling other instances. The trace instance is the
896 	 * one with most valuable information.
897 	 */
898 	if (params->trace_output)
899 		trace_instance_start(&record->trace);
900 	trace_instance_start(trace);
901 
902 	tool->start_time = time(NULL);
903 	osnoise_hist_set_signals(params);
904 
905 	while (!stop_tracing) {
906 		sleep(params->sleep_time);
907 
908 		retval = tracefs_iterate_raw_events(trace->tep,
909 						    trace->inst,
910 						    NULL,
911 						    0,
912 						    collect_registered_events,
913 						    trace);
914 		if (retval < 0) {
915 			err_msg("Error iterating on events\n");
916 			goto out_hist;
917 		}
918 
919 		if (trace_is_off(&tool->trace, &record->trace))
920 			break;
921 	}
922 
923 	osnoise_read_trace_hist(tool);
924 
925 	osnoise_print_stats(params, tool);
926 
927 	return_value = 0;
928 
929 	if (trace_is_off(&tool->trace, &record->trace)) {
930 		printf("rtla osnoise hit stop tracing\n");
931 		if (params->trace_output) {
932 			printf("  Saving trace to %s\n", params->trace_output);
933 			save_trace_to_file(record->trace.inst, params->trace_output);
934 		}
935 	}
936 
937 out_hist:
938 	trace_events_destroy(&record->trace, params->events);
939 	params->events = NULL;
940 out_free:
941 	osnoise_free_histogram(tool->data);
942 out_destroy:
943 	osnoise_destroy_tool(record);
944 	osnoise_destroy_tool(tool);
945 	free(params);
946 out_exit:
947 	exit(return_value);
948 }
949