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