xref: /linux/tools/tracing/rtla/src/osnoise_hist.c (revision cdbf71962bb07493d67fee34536a5724a8bb5886)
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 	char			no_header;
40 	char			no_summary;
41 	char			no_index;
42 	char			with_zeros;
43 	int			bucket_size;
44 	int			entries;
45 	int			warmup;
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]] [--warm-up]",
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 		"	     --warm-up: let the workload run for s seconds before collecting data",
472 		NULL,
473 	};
474 
475 	if (usage)
476 		fprintf(stderr, "%s\n", usage);
477 
478 	fprintf(stderr, "rtla osnoise hist: a per-cpu histogram of the OS noise (version %s)\n",
479 			VERSION);
480 
481 	for (i = 0; msg[i]; i++)
482 		fprintf(stderr, "%s\n", msg[i]);
483 
484 	if (usage)
485 		exit(EXIT_FAILURE);
486 
487 	exit(EXIT_SUCCESS);
488 }
489 
490 /*
491  * osnoise_hist_parse_args - allocs, parse and fill the cmd line parameters
492  */
493 static struct osnoise_hist_params
494 *osnoise_hist_parse_args(int argc, char *argv[])
495 {
496 	struct osnoise_hist_params *params;
497 	struct trace_events *tevent;
498 	int retval;
499 	int c;
500 
501 	params = calloc(1, sizeof(*params));
502 	if (!params)
503 		exit(1);
504 
505 	/* display data in microseconds */
506 	params->output_divisor = 1000;
507 	params->bucket_size = 1;
508 	params->entries = 256;
509 
510 	while (1) {
511 		static struct option long_options[] = {
512 			{"auto",		required_argument,	0, 'a'},
513 			{"bucket-size",		required_argument,	0, 'b'},
514 			{"entries",		required_argument,	0, 'E'},
515 			{"cpus",		required_argument,	0, 'c'},
516 			{"cgroup",		optional_argument,	0, 'C'},
517 			{"debug",		no_argument,		0, 'D'},
518 			{"duration",		required_argument,	0, 'd'},
519 			{"house-keeping",	required_argument,		0, 'H'},
520 			{"help",		no_argument,		0, 'h'},
521 			{"period",		required_argument,	0, 'p'},
522 			{"priority",		required_argument,	0, 'P'},
523 			{"runtime",		required_argument,	0, 'r'},
524 			{"stop",		required_argument,	0, 's'},
525 			{"stop-total",		required_argument,	0, 'S'},
526 			{"trace",		optional_argument,	0, 't'},
527 			{"event",		required_argument,	0, 'e'},
528 			{"threshold",		required_argument,	0, 'T'},
529 			{"no-header",		no_argument,		0, '0'},
530 			{"no-summary",		no_argument,		0, '1'},
531 			{"no-index",		no_argument,		0, '2'},
532 			{"with-zeros",		no_argument,		0, '3'},
533 			{"trigger",		required_argument,	0, '4'},
534 			{"filter",		required_argument,	0, '5'},
535 			{"warm-up",		required_argument,	0, '6'},
536 			{0, 0, 0, 0}
537 		};
538 
539 		/* getopt_long stores the option index here. */
540 		int option_index = 0;
541 
542 		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:p:P:r:s:S:t::T:01234:5:6:",
543 				 long_options, &option_index);
544 
545 		/* detect the end of the options. */
546 		if (c == -1)
547 			break;
548 
549 		switch (c) {
550 		case 'a':
551 			/* set sample stop to auto_thresh */
552 			params->stop_us = get_llong_from_str(optarg);
553 
554 			/* set sample threshold to 1 */
555 			params->threshold = 1;
556 
557 			/* set trace */
558 			params->trace_output = "osnoise_trace.txt";
559 
560 			break;
561 		case 'b':
562 			params->bucket_size = get_llong_from_str(optarg);
563 			if ((params->bucket_size == 0) || (params->bucket_size >= 1000000))
564 				osnoise_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
565 			break;
566 		case 'c':
567 			retval = parse_cpu_set(optarg, &params->monitored_cpus);
568 			if (retval)
569 				osnoise_hist_usage("\nInvalid -c cpu list\n");
570 			params->cpus = optarg;
571 			break;
572 		case 'C':
573 			params->cgroup = 1;
574 			if (!optarg) {
575 				/* will inherit this cgroup */
576 				params->cgroup_name = NULL;
577 			} else if (*optarg == '=') {
578 				/* skip the = */
579 				params->cgroup_name = ++optarg;
580 			}
581 			break;
582 		case 'D':
583 			config_debug = 1;
584 			break;
585 		case 'd':
586 			params->duration = parse_seconds_duration(optarg);
587 			if (!params->duration)
588 				osnoise_hist_usage("Invalid -D duration\n");
589 			break;
590 		case 'e':
591 			tevent = trace_event_alloc(optarg);
592 			if (!tevent) {
593 				err_msg("Error alloc trace event");
594 				exit(EXIT_FAILURE);
595 			}
596 
597 			if (params->events)
598 				tevent->next = params->events;
599 
600 			params->events = tevent;
601 			break;
602 		case 'E':
603 			params->entries = get_llong_from_str(optarg);
604 			if ((params->entries < 10) || (params->entries > 9999999))
605 				osnoise_hist_usage("Entries must be > 10 and < 9999999\n");
606 			break;
607 		case 'h':
608 		case '?':
609 			osnoise_hist_usage(NULL);
610 			break;
611 		case 'H':
612 			params->hk_cpus = 1;
613 			retval = parse_cpu_set(optarg, &params->hk_cpu_set);
614 			if (retval) {
615 				err_msg("Error parsing house keeping CPUs\n");
616 				exit(EXIT_FAILURE);
617 			}
618 			break;
619 		case 'p':
620 			params->period = get_llong_from_str(optarg);
621 			if (params->period > 10000000)
622 				osnoise_hist_usage("Period longer than 10 s\n");
623 			break;
624 		case 'P':
625 			retval = parse_prio(optarg, &params->sched_param);
626 			if (retval == -1)
627 				osnoise_hist_usage("Invalid -P priority");
628 			params->set_sched = 1;
629 			break;
630 		case 'r':
631 			params->runtime = get_llong_from_str(optarg);
632 			if (params->runtime < 100)
633 				osnoise_hist_usage("Runtime shorter than 100 us\n");
634 			break;
635 		case 's':
636 			params->stop_us = get_llong_from_str(optarg);
637 			break;
638 		case 'S':
639 			params->stop_total_us = get_llong_from_str(optarg);
640 			break;
641 		case 'T':
642 			params->threshold = get_llong_from_str(optarg);
643 			break;
644 		case 't':
645 			if (optarg)
646 				/* skip = */
647 				params->trace_output = &optarg[1];
648 			else
649 				params->trace_output = "osnoise_trace.txt";
650 			break;
651 		case '0': /* no header */
652 			params->no_header = 1;
653 			break;
654 		case '1': /* no summary */
655 			params->no_summary = 1;
656 			break;
657 		case '2': /* no index */
658 			params->no_index = 1;
659 			break;
660 		case '3': /* with zeros */
661 			params->with_zeros = 1;
662 			break;
663 		case '4': /* trigger */
664 			if (params->events) {
665 				retval = trace_event_add_trigger(params->events, optarg);
666 				if (retval) {
667 					err_msg("Error adding trigger %s\n", optarg);
668 					exit(EXIT_FAILURE);
669 				}
670 			} else {
671 				osnoise_hist_usage("--trigger requires a previous -e\n");
672 			}
673 			break;
674 		case '5': /* filter */
675 			if (params->events) {
676 				retval = trace_event_add_filter(params->events, optarg);
677 				if (retval) {
678 					err_msg("Error adding filter %s\n", optarg);
679 					exit(EXIT_FAILURE);
680 				}
681 			} else {
682 				osnoise_hist_usage("--filter requires a previous -e\n");
683 			}
684 			break;
685 		case '6':
686 			params->warmup = get_llong_from_str(optarg);
687 			break;
688 		default:
689 			osnoise_hist_usage("Invalid option");
690 		}
691 	}
692 
693 	if (geteuid()) {
694 		err_msg("rtla needs root permission\n");
695 		exit(EXIT_FAILURE);
696 	}
697 
698 	if (params->no_index && !params->with_zeros)
699 		osnoise_hist_usage("no-index set and with-zeros not set - it does not make sense");
700 
701 	return params;
702 }
703 
704 /*
705  * osnoise_hist_apply_config - apply the hist configs to the initialized tool
706  */
707 static int
708 osnoise_hist_apply_config(struct osnoise_tool *tool, struct osnoise_hist_params *params)
709 {
710 	int retval;
711 
712 	if (!params->sleep_time)
713 		params->sleep_time = 1;
714 
715 	if (params->cpus) {
716 		retval = osnoise_set_cpus(tool->context, params->cpus);
717 		if (retval) {
718 			err_msg("Failed to apply CPUs config\n");
719 			goto out_err;
720 		}
721 	}
722 
723 	if (params->runtime || params->period) {
724 		retval = osnoise_set_runtime_period(tool->context,
725 						    params->runtime,
726 						    params->period);
727 		if (retval) {
728 			err_msg("Failed to set runtime and/or period\n");
729 			goto out_err;
730 		}
731 	}
732 
733 	if (params->stop_us) {
734 		retval = osnoise_set_stop_us(tool->context, params->stop_us);
735 		if (retval) {
736 			err_msg("Failed to set stop us\n");
737 			goto out_err;
738 		}
739 	}
740 
741 	if (params->stop_total_us) {
742 		retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
743 		if (retval) {
744 			err_msg("Failed to set stop total us\n");
745 			goto out_err;
746 		}
747 	}
748 
749 	if (params->threshold) {
750 		retval = osnoise_set_tracing_thresh(tool->context, params->threshold);
751 		if (retval) {
752 			err_msg("Failed to set tracing_thresh\n");
753 			goto out_err;
754 		}
755 	}
756 
757 	if (params->hk_cpus) {
758 		retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
759 					   &params->hk_cpu_set);
760 		if (retval == -1) {
761 			err_msg("Failed to set rtla to the house keeping CPUs\n");
762 			goto out_err;
763 		}
764 	} else if (params->cpus) {
765 		/*
766 		 * Even if the user do not set a house-keeping CPU, try to
767 		 * move rtla to a CPU set different to the one where the user
768 		 * set the workload to run.
769 		 *
770 		 * No need to check results as this is an automatic attempt.
771 		 */
772 		auto_house_keeping(&params->monitored_cpus);
773 	}
774 
775 	return 0;
776 
777 out_err:
778 	return -1;
779 }
780 
781 /*
782  * osnoise_init_hist - initialize a osnoise hist tool with parameters
783  */
784 static struct osnoise_tool
785 *osnoise_init_hist(struct osnoise_hist_params *params)
786 {
787 	struct osnoise_tool *tool;
788 	int nr_cpus;
789 
790 	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
791 
792 	tool = osnoise_init_tool("osnoise_hist");
793 	if (!tool)
794 		return NULL;
795 
796 	tool->data = osnoise_alloc_histogram(nr_cpus, params->entries, params->bucket_size);
797 	if (!tool->data)
798 		goto out_err;
799 
800 	tool->params = params;
801 
802 	return tool;
803 
804 out_err:
805 	osnoise_destroy_tool(tool);
806 	return NULL;
807 }
808 
809 static int stop_tracing;
810 static void stop_hist(int sig)
811 {
812 	stop_tracing = 1;
813 }
814 
815 /*
816  * osnoise_hist_set_signals - handles the signal to stop the tool
817  */
818 static void
819 osnoise_hist_set_signals(struct osnoise_hist_params *params)
820 {
821 	signal(SIGINT, stop_hist);
822 	if (params->duration) {
823 		signal(SIGALRM, stop_hist);
824 		alarm(params->duration);
825 	}
826 }
827 
828 int osnoise_hist_main(int argc, char *argv[])
829 {
830 	struct osnoise_hist_params *params;
831 	struct osnoise_tool *record = NULL;
832 	struct osnoise_tool *tool = NULL;
833 	struct trace_instance *trace;
834 	int return_value = 1;
835 	int retval;
836 
837 	params = osnoise_hist_parse_args(argc, argv);
838 	if (!params)
839 		exit(1);
840 
841 	tool = osnoise_init_hist(params);
842 	if (!tool) {
843 		err_msg("Could not init osnoise hist\n");
844 		goto out_exit;
845 	}
846 
847 	retval = osnoise_hist_apply_config(tool, params);
848 	if (retval) {
849 		err_msg("Could not apply config\n");
850 		goto out_destroy;
851 	}
852 
853 	trace = &tool->trace;
854 
855 	retval = enable_osnoise(trace);
856 	if (retval) {
857 		err_msg("Failed to enable osnoise tracer\n");
858 		goto out_destroy;
859 	}
860 
861 	retval = osnoise_init_trace_hist(tool);
862 	if (retval)
863 		goto out_destroy;
864 
865 	if (params->set_sched) {
866 		retval = set_comm_sched_attr("osnoise/", &params->sched_param);
867 		if (retval) {
868 			err_msg("Failed to set sched parameters\n");
869 			goto out_free;
870 		}
871 	}
872 
873 	if (params->cgroup) {
874 		retval = set_comm_cgroup("timerlat/", params->cgroup_name);
875 		if (!retval) {
876 			err_msg("Failed to move threads to cgroup\n");
877 			goto out_free;
878 		}
879 	}
880 
881 	if (params->trace_output) {
882 		record = osnoise_init_trace_tool("osnoise");
883 		if (!record) {
884 			err_msg("Failed to enable the trace instance\n");
885 			goto out_free;
886 		}
887 
888 		if (params->events) {
889 			retval = trace_events_enable(&record->trace, params->events);
890 			if (retval)
891 				goto out_hist;
892 		}
893 
894 	}
895 
896 	/*
897 	 * Start the tracer here, after having set all instances.
898 	 *
899 	 * Let the trace instance start first for the case of hitting a stop
900 	 * tracing while enabling other instances. The trace instance is the
901 	 * one with most valuable information.
902 	 */
903 	if (params->trace_output)
904 		trace_instance_start(&record->trace);
905 	trace_instance_start(trace);
906 
907 	if (params->warmup > 0) {
908 		debug_msg("Warming up for %d seconds\n", params->warmup);
909 		sleep(params->warmup);
910 		if (stop_tracing)
911 			goto out_hist;
912 
913 		/*
914 		 * Clean up the buffer. The osnoise workload do not run
915 		 * with tracing off to avoid creating a performance penalty
916 		 * when not needed.
917 		 */
918 		retval = tracefs_instance_file_write(trace->inst, "trace", "");
919 		if (retval < 0) {
920 			debug_msg("Error cleaning up the buffer");
921 			goto out_hist;
922 		}
923 
924 	}
925 
926 	tool->start_time = time(NULL);
927 	osnoise_hist_set_signals(params);
928 
929 	while (!stop_tracing) {
930 		sleep(params->sleep_time);
931 
932 		retval = tracefs_iterate_raw_events(trace->tep,
933 						    trace->inst,
934 						    NULL,
935 						    0,
936 						    collect_registered_events,
937 						    trace);
938 		if (retval < 0) {
939 			err_msg("Error iterating on events\n");
940 			goto out_hist;
941 		}
942 
943 		if (trace_is_off(&tool->trace, &record->trace))
944 			break;
945 	}
946 
947 	osnoise_read_trace_hist(tool);
948 
949 	osnoise_print_stats(params, tool);
950 
951 	return_value = 0;
952 
953 	if (trace_is_off(&tool->trace, &record->trace)) {
954 		printf("rtla osnoise hit stop tracing\n");
955 		if (params->trace_output) {
956 			printf("  Saving trace to %s\n", params->trace_output);
957 			save_trace_to_file(record->trace.inst, params->trace_output);
958 		}
959 	}
960 
961 out_hist:
962 	trace_events_destroy(&record->trace, params->events);
963 	params->events = NULL;
964 out_free:
965 	osnoise_free_histogram(tool->data);
966 out_destroy:
967 	osnoise_destroy_tool(record);
968 	osnoise_destroy_tool(tool);
969 	free(params);
970 out_exit:
971 	exit(return_value);
972 }
973