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 <stdio.h>
13 #include <time.h>
14 #include <sched.h>
15 #include <pthread.h>
16 
17 #include "utils.h"
18 #include "osnoise.h"
19 #include "timerlat.h"
20 #include "timerlat_aa.h"
21 #include "timerlat_u.h"
22 
23 struct timerlat_hist_params {
24 	char			*cpus;
25 	cpu_set_t		monitored_cpus;
26 	char			*trace_output;
27 	char			*cgroup_name;
28 	unsigned long long	runtime;
29 	long long		stop_us;
30 	long long		stop_total_us;
31 	long long		timerlat_period_us;
32 	long long		print_stack;
33 	int			sleep_time;
34 	int			output_divisor;
35 	int			duration;
36 	int			set_sched;
37 	int			dma_latency;
38 	int			cgroup;
39 	int			hk_cpus;
40 	int			no_aa;
41 	int			dump_tasks;
42 	int			user_hist;
43 	cpu_set_t		hk_cpu_set;
44 	struct sched_attr	sched_param;
45 	struct trace_events	*events;
46 	char			no_irq;
47 	char			no_thread;
48 	char			no_header;
49 	char			no_summary;
50 	char			no_index;
51 	char			with_zeros;
52 	int			bucket_size;
53 	int			entries;
54 };
55 
56 struct timerlat_hist_cpu {
57 	int			*irq;
58 	int			*thread;
59 	int			*user;
60 
61 	int			irq_count;
62 	int			thread_count;
63 	int			user_count;
64 
65 	unsigned long long	min_irq;
66 	unsigned long long	sum_irq;
67 	unsigned long long	max_irq;
68 
69 	unsigned long long	min_thread;
70 	unsigned long long	sum_thread;
71 	unsigned long long	max_thread;
72 
73 	unsigned long long	min_user;
74 	unsigned long long	sum_user;
75 	unsigned long long	max_user;
76 };
77 
78 struct timerlat_hist_data {
79 	struct timerlat_hist_cpu	*hist;
80 	int				entries;
81 	int				bucket_size;
82 	int				nr_cpus;
83 };
84 
85 /*
86  * timerlat_free_histogram - free runtime data
87  */
88 static void
89 timerlat_free_histogram(struct timerlat_hist_data *data)
90 {
91 	int cpu;
92 
93 	/* one histogram for IRQ and one for thread, per CPU */
94 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
95 		if (data->hist[cpu].irq)
96 			free(data->hist[cpu].irq);
97 
98 		if (data->hist[cpu].thread)
99 			free(data->hist[cpu].thread);
100 
101 		if (data->hist[cpu].user)
102 			free(data->hist[cpu].user);
103 
104 	}
105 
106 	/* one set of histograms per CPU */
107 	if (data->hist)
108 		free(data->hist);
109 
110 	free(data);
111 }
112 
113 /*
114  * timerlat_alloc_histogram - alloc runtime data
115  */
116 static struct timerlat_hist_data
117 *timerlat_alloc_histogram(int nr_cpus, int entries, int bucket_size)
118 {
119 	struct timerlat_hist_data *data;
120 	int cpu;
121 
122 	data = calloc(1, sizeof(*data));
123 	if (!data)
124 		return NULL;
125 
126 	data->entries = entries;
127 	data->bucket_size = bucket_size;
128 	data->nr_cpus = nr_cpus;
129 
130 	/* one set of histograms per CPU */
131 	data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
132 	if (!data->hist)
133 		goto cleanup;
134 
135 	/* one histogram for IRQ and one for thread, per cpu */
136 	for (cpu = 0; cpu < nr_cpus; cpu++) {
137 		data->hist[cpu].irq = calloc(1, sizeof(*data->hist->irq) * (entries + 1));
138 		if (!data->hist[cpu].irq)
139 			goto cleanup;
140 
141 		data->hist[cpu].thread = calloc(1, sizeof(*data->hist->thread) * (entries + 1));
142 		if (!data->hist[cpu].thread)
143 			goto cleanup;
144 
145 		data->hist[cpu].user = calloc(1, sizeof(*data->hist->user) * (entries + 1));
146 		if (!data->hist[cpu].user)
147 			goto cleanup;
148 	}
149 
150 	/* set the min to max */
151 	for (cpu = 0; cpu < nr_cpus; cpu++) {
152 		data->hist[cpu].min_irq = ~0;
153 		data->hist[cpu].min_thread = ~0;
154 		data->hist[cpu].min_user = ~0;
155 	}
156 
157 	return data;
158 
159 cleanup:
160 	timerlat_free_histogram(data);
161 	return NULL;
162 }
163 
164 /*
165  * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
166  */
167 static void
168 timerlat_hist_update(struct osnoise_tool *tool, int cpu,
169 		     unsigned long long context,
170 		     unsigned long long latency)
171 {
172 	struct timerlat_hist_params *params = tool->params;
173 	struct timerlat_hist_data *data = tool->data;
174 	int entries = data->entries;
175 	int bucket;
176 	int *hist;
177 
178 	if (params->output_divisor)
179 		latency = latency / params->output_divisor;
180 
181 	bucket = latency / data->bucket_size;
182 
183 	if (!context) {
184 		hist = data->hist[cpu].irq;
185 		data->hist[cpu].irq_count++;
186 		update_min(&data->hist[cpu].min_irq, &latency);
187 		update_sum(&data->hist[cpu].sum_irq, &latency);
188 		update_max(&data->hist[cpu].max_irq, &latency);
189 	} else if (context == 1) {
190 		hist = data->hist[cpu].thread;
191 		data->hist[cpu].thread_count++;
192 		update_min(&data->hist[cpu].min_thread, &latency);
193 		update_sum(&data->hist[cpu].sum_thread, &latency);
194 		update_max(&data->hist[cpu].max_thread, &latency);
195 	} else { /* user */
196 		hist = data->hist[cpu].user;
197 		data->hist[cpu].user_count++;
198 		update_min(&data->hist[cpu].min_user, &latency);
199 		update_sum(&data->hist[cpu].sum_user, &latency);
200 		update_max(&data->hist[cpu].max_user, &latency);
201 	}
202 
203 	if (bucket < entries)
204 		hist[bucket]++;
205 	else
206 		hist[entries]++;
207 }
208 
209 /*
210  * timerlat_hist_handler - this is the handler for timerlat tracer events
211  */
212 static int
213 timerlat_hist_handler(struct trace_seq *s, struct tep_record *record,
214 		     struct tep_event *event, void *data)
215 {
216 	struct trace_instance *trace = data;
217 	unsigned long long context, latency;
218 	struct osnoise_tool *tool;
219 	int cpu = record->cpu;
220 
221 	tool = container_of(trace, struct osnoise_tool, trace);
222 
223 	tep_get_field_val(s, event, "context", record, &context, 1);
224 	tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
225 
226 	timerlat_hist_update(tool, cpu, context, latency);
227 
228 	return 0;
229 }
230 
231 /*
232  * timerlat_hist_header - print the header of the tracer to the output
233  */
234 static void timerlat_hist_header(struct osnoise_tool *tool)
235 {
236 	struct timerlat_hist_params *params = tool->params;
237 	struct timerlat_hist_data *data = tool->data;
238 	struct trace_seq *s = tool->trace.seq;
239 	char duration[26];
240 	int cpu;
241 
242 	if (params->no_header)
243 		return;
244 
245 	get_duration(tool->start_time, duration, sizeof(duration));
246 	trace_seq_printf(s, "# RTLA timerlat histogram\n");
247 	trace_seq_printf(s, "# Time unit is %s (%s)\n",
248 			params->output_divisor == 1 ? "nanoseconds" : "microseconds",
249 			params->output_divisor == 1 ? "ns" : "us");
250 
251 	trace_seq_printf(s, "# Duration: %s\n", duration);
252 
253 	if (!params->no_index)
254 		trace_seq_printf(s, "Index");
255 
256 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
257 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
258 			continue;
259 
260 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
261 			continue;
262 
263 		if (!params->no_irq)
264 			trace_seq_printf(s, "   IRQ-%03d", cpu);
265 
266 		if (!params->no_thread)
267 			trace_seq_printf(s, "   Thr-%03d", cpu);
268 
269 		if (params->user_hist)
270 			trace_seq_printf(s, "   Usr-%03d", cpu);
271 	}
272 	trace_seq_printf(s, "\n");
273 
274 
275 	trace_seq_do_printf(s);
276 	trace_seq_reset(s);
277 }
278 
279 /*
280  * timerlat_print_summary - print the summary of the hist data to the output
281  */
282 static void
283 timerlat_print_summary(struct timerlat_hist_params *params,
284 		       struct trace_instance *trace,
285 		       struct timerlat_hist_data *data)
286 {
287 	int cpu;
288 
289 	if (params->no_summary)
290 		return;
291 
292 	if (!params->no_index)
293 		trace_seq_printf(trace->seq, "count:");
294 
295 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
296 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
297 			continue;
298 
299 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
300 			continue;
301 
302 		if (!params->no_irq)
303 			trace_seq_printf(trace->seq, "%9d ",
304 					data->hist[cpu].irq_count);
305 
306 		if (!params->no_thread)
307 			trace_seq_printf(trace->seq, "%9d ",
308 					data->hist[cpu].thread_count);
309 
310 		if (params->user_hist)
311 			trace_seq_printf(trace->seq, "%9d ",
312 					 data->hist[cpu].user_count);
313 	}
314 	trace_seq_printf(trace->seq, "\n");
315 
316 	if (!params->no_index)
317 		trace_seq_printf(trace->seq, "min:  ");
318 
319 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
320 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
321 			continue;
322 
323 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
324 			continue;
325 
326 		if (!params->no_irq)
327 			trace_seq_printf(trace->seq, "%9llu ",
328 					data->hist[cpu].min_irq);
329 
330 		if (!params->no_thread)
331 			trace_seq_printf(trace->seq, "%9llu ",
332 					data->hist[cpu].min_thread);
333 
334 		if (params->user_hist)
335 			trace_seq_printf(trace->seq, "%9llu ",
336 					data->hist[cpu].min_user);
337 	}
338 	trace_seq_printf(trace->seq, "\n");
339 
340 	if (!params->no_index)
341 		trace_seq_printf(trace->seq, "avg:  ");
342 
343 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
344 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
345 			continue;
346 
347 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
348 			continue;
349 
350 		if (!params->no_irq) {
351 			if (data->hist[cpu].irq_count)
352 				trace_seq_printf(trace->seq, "%9llu ",
353 						 data->hist[cpu].sum_irq / data->hist[cpu].irq_count);
354 			else
355 				trace_seq_printf(trace->seq, "        - ");
356 		}
357 
358 		if (!params->no_thread) {
359 			if (data->hist[cpu].thread_count)
360 				trace_seq_printf(trace->seq, "%9llu ",
361 						 data->hist[cpu].sum_thread / data->hist[cpu].thread_count);
362 			else
363 				trace_seq_printf(trace->seq, "        - ");
364 		}
365 
366 		if (params->user_hist) {
367 			if (data->hist[cpu].user_count)
368 				trace_seq_printf(trace->seq, "%9llu ",
369 						 data->hist[cpu].sum_user / data->hist[cpu].user_count);
370 			else
371 				trace_seq_printf(trace->seq, "        - ");
372 		}
373 	}
374 	trace_seq_printf(trace->seq, "\n");
375 
376 	if (!params->no_index)
377 		trace_seq_printf(trace->seq, "max:  ");
378 
379 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
380 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
381 			continue;
382 
383 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
384 			continue;
385 
386 		if (!params->no_irq)
387 			trace_seq_printf(trace->seq, "%9llu ",
388 					data->hist[cpu].max_irq);
389 
390 		if (!params->no_thread)
391 			trace_seq_printf(trace->seq, "%9llu ",
392 					data->hist[cpu].max_thread);
393 
394 		if (params->user_hist)
395 			trace_seq_printf(trace->seq, "%9llu ",
396 					data->hist[cpu].max_user);
397 	}
398 	trace_seq_printf(trace->seq, "\n");
399 	trace_seq_do_printf(trace->seq);
400 	trace_seq_reset(trace->seq);
401 }
402 
403 /*
404  * timerlat_print_stats - print data for all CPUs
405  */
406 static void
407 timerlat_print_stats(struct timerlat_hist_params *params, struct osnoise_tool *tool)
408 {
409 	struct timerlat_hist_data *data = tool->data;
410 	struct trace_instance *trace = &tool->trace;
411 	int bucket, cpu;
412 	int total;
413 
414 	timerlat_hist_header(tool);
415 
416 	for (bucket = 0; bucket < data->entries; bucket++) {
417 		total = 0;
418 
419 		if (!params->no_index)
420 			trace_seq_printf(trace->seq, "%-6d",
421 					 bucket * data->bucket_size);
422 
423 		for (cpu = 0; cpu < data->nr_cpus; cpu++) {
424 			if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
425 				continue;
426 
427 			if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
428 				continue;
429 
430 			if (!params->no_irq) {
431 				total += data->hist[cpu].irq[bucket];
432 				trace_seq_printf(trace->seq, "%9d ",
433 						data->hist[cpu].irq[bucket]);
434 			}
435 
436 			if (!params->no_thread) {
437 				total += data->hist[cpu].thread[bucket];
438 				trace_seq_printf(trace->seq, "%9d ",
439 						data->hist[cpu].thread[bucket]);
440 			}
441 
442 			if (params->user_hist) {
443 				total += data->hist[cpu].user[bucket];
444 				trace_seq_printf(trace->seq, "%9d ",
445 						data->hist[cpu].user[bucket]);
446 			}
447 
448 		}
449 
450 		if (total == 0 && !params->with_zeros) {
451 			trace_seq_reset(trace->seq);
452 			continue;
453 		}
454 
455 		trace_seq_printf(trace->seq, "\n");
456 		trace_seq_do_printf(trace->seq);
457 		trace_seq_reset(trace->seq);
458 	}
459 
460 	if (!params->no_index)
461 		trace_seq_printf(trace->seq, "over: ");
462 
463 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
464 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
465 			continue;
466 
467 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
468 			continue;
469 
470 		if (!params->no_irq)
471 			trace_seq_printf(trace->seq, "%9d ",
472 					 data->hist[cpu].irq[data->entries]);
473 
474 		if (!params->no_thread)
475 			trace_seq_printf(trace->seq, "%9d ",
476 					 data->hist[cpu].thread[data->entries]);
477 
478 		if (params->user_hist)
479 			trace_seq_printf(trace->seq, "%9d ",
480 					 data->hist[cpu].user[data->entries]);
481 	}
482 	trace_seq_printf(trace->seq, "\n");
483 	trace_seq_do_printf(trace->seq);
484 	trace_seq_reset(trace->seq);
485 
486 	timerlat_print_summary(params, trace, data);
487 }
488 
489 /*
490  * timerlat_hist_usage - prints timerlat top usage message
491  */
492 static void timerlat_hist_usage(char *usage)
493 {
494 	int i;
495 
496 	char *msg[] = {
497 		"",
498 		"  usage: [rtla] timerlat hist [-h] [-q] [-d s] [-D] [-n] [-a us] [-p us] [-i us] [-T us] [-s us] \\",
499 		"         [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
500 		"	  [-P priority] [-E N] [-b N] [--no-irq] [--no-thread] [--no-header] [--no-summary] \\",
501 		"	  [--no-index] [--with-zeros] [--dma-latency us] [-C[=cgroup_name]] [--no-aa] [--dump-task] [-u]",
502 		"",
503 		"	  -h/--help: print this menu",
504 		"	  -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
505 		"	  -p/--period us: timerlat period in us",
506 		"	  -i/--irq us: stop trace if the irq latency is higher than the argument in us",
507 		"	  -T/--thread us: stop trace if the thread latency is higher than the argument in us",
508 		"	  -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
509 		"	  -c/--cpus cpus: run the tracer only on the given cpus",
510 		"	  -H/--house-keeping cpus: run rtla control threads only on the given cpus",
511 		"	  -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
512 		"	  -d/--duration time[m|h|d]: duration of the session in seconds",
513 		"	     --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
514 		"	  -D/--debug: print debug info",
515 		"	  -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]",
516 		"	  -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
517 		"	     --filter <filter>: enable a trace event filter to the previous -e event",
518 		"	     --trigger <trigger>: enable a trace event trigger to the previous -e event",
519 		"	  -n/--nano: display data in nanoseconds",
520 		"	     --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",
521 		"	  -b/--bucket-size N: set the histogram bucket size (default 1)",
522 		"	  -E/--entries N: set the number of entries of the histogram (default 256)",
523 		"	     --no-irq: ignore IRQ latencies",
524 		"	     --no-thread: ignore thread latencies",
525 		"	     --no-header: do not print header",
526 		"	     --no-summary: do not print summary",
527 		"	     --no-index: do not print index",
528 		"	     --with-zeros: print zero only entries",
529 		"	     --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
530 		"	  -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
531 		"		o:prio - use SCHED_OTHER with prio",
532 		"		r:prio - use SCHED_RR with prio",
533 		"		f:prio - use SCHED_FIFO with prio",
534 		"		d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
535 		"						       in nanoseconds",
536 		"	  -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads",
537 		NULL,
538 	};
539 
540 	if (usage)
541 		fprintf(stderr, "%s\n", usage);
542 
543 	fprintf(stderr, "rtla timerlat hist: a per-cpu histogram of the timer latency (version %s)\n",
544 			VERSION);
545 
546 	for (i = 0; msg[i]; i++)
547 		fprintf(stderr, "%s\n", msg[i]);
548 
549 	if (usage)
550 		exit(EXIT_FAILURE);
551 
552 	exit(EXIT_SUCCESS);
553 }
554 
555 /*
556  * timerlat_hist_parse_args - allocs, parse and fill the cmd line parameters
557  */
558 static struct timerlat_hist_params
559 *timerlat_hist_parse_args(int argc, char *argv[])
560 {
561 	struct timerlat_hist_params *params;
562 	struct trace_events *tevent;
563 	int auto_thresh;
564 	int retval;
565 	int c;
566 
567 	params = calloc(1, sizeof(*params));
568 	if (!params)
569 		exit(1);
570 
571 	/* disabled by default */
572 	params->dma_latency = -1;
573 
574 	/* display data in microseconds */
575 	params->output_divisor = 1000;
576 	params->bucket_size = 1;
577 	params->entries = 256;
578 
579 	while (1) {
580 		static struct option long_options[] = {
581 			{"auto",		required_argument,	0, 'a'},
582 			{"cpus",		required_argument,	0, 'c'},
583 			{"cgroup",		optional_argument,	0, 'C'},
584 			{"bucket-size",		required_argument,	0, 'b'},
585 			{"debug",		no_argument,		0, 'D'},
586 			{"entries",		required_argument,	0, 'E'},
587 			{"duration",		required_argument,	0, 'd'},
588 			{"house-keeping",	required_argument,	0, 'H'},
589 			{"help",		no_argument,		0, 'h'},
590 			{"irq",			required_argument,	0, 'i'},
591 			{"nano",		no_argument,		0, 'n'},
592 			{"period",		required_argument,	0, 'p'},
593 			{"priority",		required_argument,	0, 'P'},
594 			{"stack",		required_argument,	0, 's'},
595 			{"thread",		required_argument,	0, 'T'},
596 			{"trace",		optional_argument,	0, 't'},
597 			{"user-threads",	no_argument,		0, 'u'},
598 			{"event",		required_argument,	0, 'e'},
599 			{"no-irq",		no_argument,		0, '0'},
600 			{"no-thread",		no_argument,		0, '1'},
601 			{"no-header",		no_argument,		0, '2'},
602 			{"no-summary",		no_argument,		0, '3'},
603 			{"no-index",		no_argument,		0, '4'},
604 			{"with-zeros",		no_argument,		0, '5'},
605 			{"trigger",		required_argument,	0, '6'},
606 			{"filter",		required_argument,	0, '7'},
607 			{"dma-latency",		required_argument,	0, '8'},
608 			{"no-aa",		no_argument,		0, '9'},
609 			{"dump-task",		no_argument,		0, '\1'},
610 			{0, 0, 0, 0}
611 		};
612 
613 		/* getopt_long stores the option index here. */
614 		int option_index = 0;
615 
616 		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:u0123456:7:8:9\1",
617 				 long_options, &option_index);
618 
619 		/* detect the end of the options. */
620 		if (c == -1)
621 			break;
622 
623 		switch (c) {
624 		case 'a':
625 			auto_thresh = get_llong_from_str(optarg);
626 
627 			/* set thread stop to auto_thresh */
628 			params->stop_total_us = auto_thresh;
629 			params->stop_us = auto_thresh;
630 
631 			/* get stack trace */
632 			params->print_stack = auto_thresh;
633 
634 			/* set trace */
635 			params->trace_output = "timerlat_trace.txt";
636 
637 			break;
638 		case 'c':
639 			retval = parse_cpu_set(optarg, &params->monitored_cpus);
640 			if (retval)
641 				timerlat_hist_usage("\nInvalid -c cpu list\n");
642 			params->cpus = optarg;
643 			break;
644 		case 'C':
645 			params->cgroup = 1;
646 			if (!optarg) {
647 				/* will inherit this cgroup */
648 				params->cgroup_name = NULL;
649 			} else if (*optarg == '=') {
650 				/* skip the = */
651 				params->cgroup_name = ++optarg;
652 			}
653 			break;
654 		case 'b':
655 			params->bucket_size = get_llong_from_str(optarg);
656 			if ((params->bucket_size == 0) || (params->bucket_size >= 1000000))
657 				timerlat_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
658 			break;
659 		case 'D':
660 			config_debug = 1;
661 			break;
662 		case 'd':
663 			params->duration = parse_seconds_duration(optarg);
664 			if (!params->duration)
665 				timerlat_hist_usage("Invalid -D duration\n");
666 			break;
667 		case 'e':
668 			tevent = trace_event_alloc(optarg);
669 			if (!tevent) {
670 				err_msg("Error alloc trace event");
671 				exit(EXIT_FAILURE);
672 			}
673 
674 			if (params->events)
675 				tevent->next = params->events;
676 
677 			params->events = tevent;
678 			break;
679 		case 'E':
680 			params->entries = get_llong_from_str(optarg);
681 			if ((params->entries < 10) || (params->entries > 9999999))
682 					timerlat_hist_usage("Entries must be > 10 and < 9999999\n");
683 			break;
684 		case 'h':
685 		case '?':
686 			timerlat_hist_usage(NULL);
687 			break;
688 		case 'H':
689 			params->hk_cpus = 1;
690 			retval = parse_cpu_set(optarg, &params->hk_cpu_set);
691 			if (retval) {
692 				err_msg("Error parsing house keeping CPUs\n");
693 				exit(EXIT_FAILURE);
694 			}
695 			break;
696 		case 'i':
697 			params->stop_us = get_llong_from_str(optarg);
698 			break;
699 		case 'n':
700 			params->output_divisor = 1;
701 			break;
702 		case 'p':
703 			params->timerlat_period_us = get_llong_from_str(optarg);
704 			if (params->timerlat_period_us > 1000000)
705 				timerlat_hist_usage("Period longer than 1 s\n");
706 			break;
707 		case 'P':
708 			retval = parse_prio(optarg, &params->sched_param);
709 			if (retval == -1)
710 				timerlat_hist_usage("Invalid -P priority");
711 			params->set_sched = 1;
712 			break;
713 		case 's':
714 			params->print_stack = get_llong_from_str(optarg);
715 			break;
716 		case 'T':
717 			params->stop_total_us = get_llong_from_str(optarg);
718 			break;
719 		case 't':
720 			if (optarg)
721 				/* skip = */
722 				params->trace_output = &optarg[1];
723 			else
724 				params->trace_output = "timerlat_trace.txt";
725 			break;
726 		case 'u':
727 			params->user_hist = 1;
728 			break;
729 		case '0': /* no irq */
730 			params->no_irq = 1;
731 			break;
732 		case '1': /* no thread */
733 			params->no_thread = 1;
734 			break;
735 		case '2': /* no header */
736 			params->no_header = 1;
737 			break;
738 		case '3': /* no summary */
739 			params->no_summary = 1;
740 			break;
741 		case '4': /* no index */
742 			params->no_index = 1;
743 			break;
744 		case '5': /* with zeros */
745 			params->with_zeros = 1;
746 			break;
747 		case '6': /* trigger */
748 			if (params->events) {
749 				retval = trace_event_add_trigger(params->events, optarg);
750 				if (retval) {
751 					err_msg("Error adding trigger %s\n", optarg);
752 					exit(EXIT_FAILURE);
753 				}
754 			} else {
755 				timerlat_hist_usage("--trigger requires a previous -e\n");
756 			}
757 			break;
758 		case '7': /* filter */
759 			if (params->events) {
760 				retval = trace_event_add_filter(params->events, optarg);
761 				if (retval) {
762 					err_msg("Error adding filter %s\n", optarg);
763 					exit(EXIT_FAILURE);
764 				}
765 			} else {
766 				timerlat_hist_usage("--filter requires a previous -e\n");
767 			}
768 			break;
769 		case '8':
770 			params->dma_latency = get_llong_from_str(optarg);
771 			if (params->dma_latency < 0 || params->dma_latency > 10000) {
772 				err_msg("--dma-latency needs to be >= 0 and < 10000");
773 				exit(EXIT_FAILURE);
774 			}
775 			break;
776 		case '9':
777 			params->no_aa = 1;
778 			break;
779 		case '\1':
780 			params->dump_tasks = 1;
781 			break;
782 		default:
783 			timerlat_hist_usage("Invalid option");
784 		}
785 	}
786 
787 	if (geteuid()) {
788 		err_msg("rtla needs root permission\n");
789 		exit(EXIT_FAILURE);
790 	}
791 
792 	if (params->no_irq && params->no_thread)
793 		timerlat_hist_usage("no-irq and no-thread set, there is nothing to do here");
794 
795 	if (params->no_index && !params->with_zeros)
796 		timerlat_hist_usage("no-index set with with-zeros is not set - it does not make sense");
797 
798 	/*
799 	 * Auto analysis only happens if stop tracing, thus:
800 	 */
801 	if (!params->stop_us && !params->stop_total_us)
802 		params->no_aa = 1;
803 
804 	return params;
805 }
806 
807 /*
808  * timerlat_hist_apply_config - apply the hist configs to the initialized tool
809  */
810 static int
811 timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_params *params)
812 {
813 	int retval, i;
814 
815 	if (!params->sleep_time)
816 		params->sleep_time = 1;
817 
818 	if (params->cpus) {
819 		retval = osnoise_set_cpus(tool->context, params->cpus);
820 		if (retval) {
821 			err_msg("Failed to apply CPUs config\n");
822 			goto out_err;
823 		}
824 	} else {
825 		for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
826 			CPU_SET(i, &params->monitored_cpus);
827 	}
828 
829 	if (params->stop_us) {
830 		retval = osnoise_set_stop_us(tool->context, params->stop_us);
831 		if (retval) {
832 			err_msg("Failed to set stop us\n");
833 			goto out_err;
834 		}
835 	}
836 
837 	if (params->stop_total_us) {
838 		retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
839 		if (retval) {
840 			err_msg("Failed to set stop total us\n");
841 			goto out_err;
842 		}
843 	}
844 
845 	if (params->timerlat_period_us) {
846 		retval = osnoise_set_timerlat_period_us(tool->context, params->timerlat_period_us);
847 		if (retval) {
848 			err_msg("Failed to set timerlat period\n");
849 			goto out_err;
850 		}
851 	}
852 
853 	if (params->print_stack) {
854 		retval = osnoise_set_print_stack(tool->context, params->print_stack);
855 		if (retval) {
856 			err_msg("Failed to set print stack\n");
857 			goto out_err;
858 		}
859 	}
860 
861 	if (params->hk_cpus) {
862 		retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
863 					   &params->hk_cpu_set);
864 		if (retval == -1) {
865 			err_msg("Failed to set rtla to the house keeping CPUs\n");
866 			goto out_err;
867 		}
868 	} else if (params->cpus) {
869 		/*
870 		 * Even if the user do not set a house-keeping CPU, try to
871 		 * move rtla to a CPU set different to the one where the user
872 		 * set the workload to run.
873 		 *
874 		 * No need to check results as this is an automatic attempt.
875 		 */
876 		auto_house_keeping(&params->monitored_cpus);
877 	}
878 
879 	if (params->user_hist) {
880 		retval = osnoise_set_workload(tool->context, 0);
881 		if (retval) {
882 			err_msg("Failed to set OSNOISE_WORKLOAD option\n");
883 			goto out_err;
884 		}
885 	}
886 
887 	return 0;
888 
889 out_err:
890 	return -1;
891 }
892 
893 /*
894  * timerlat_init_hist - initialize a timerlat hist tool with parameters
895  */
896 static struct osnoise_tool
897 *timerlat_init_hist(struct timerlat_hist_params *params)
898 {
899 	struct osnoise_tool *tool;
900 	int nr_cpus;
901 
902 	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
903 
904 	tool = osnoise_init_tool("timerlat_hist");
905 	if (!tool)
906 		return NULL;
907 
908 	tool->data = timerlat_alloc_histogram(nr_cpus, params->entries, params->bucket_size);
909 	if (!tool->data)
910 		goto out_err;
911 
912 	tool->params = params;
913 
914 	tep_register_event_handler(tool->trace.tep, -1, "ftrace", "timerlat",
915 				   timerlat_hist_handler, tool);
916 
917 	return tool;
918 
919 out_err:
920 	osnoise_destroy_tool(tool);
921 	return NULL;
922 }
923 
924 static int stop_tracing;
925 static void stop_hist(int sig)
926 {
927 	stop_tracing = 1;
928 }
929 
930 /*
931  * timerlat_hist_set_signals - handles the signal to stop the tool
932  */
933 static void
934 timerlat_hist_set_signals(struct timerlat_hist_params *params)
935 {
936 	signal(SIGINT, stop_hist);
937 	if (params->duration) {
938 		signal(SIGALRM, stop_hist);
939 		alarm(params->duration);
940 	}
941 }
942 
943 int timerlat_hist_main(int argc, char *argv[])
944 {
945 	struct timerlat_hist_params *params;
946 	struct osnoise_tool *record = NULL;
947 	struct timerlat_u_params params_u;
948 	struct osnoise_tool *tool = NULL;
949 	struct osnoise_tool *aa = NULL;
950 	struct trace_instance *trace;
951 	int dma_latency_fd = -1;
952 	int return_value = 1;
953 	pthread_t timerlat_u;
954 	int retval;
955 
956 	params = timerlat_hist_parse_args(argc, argv);
957 	if (!params)
958 		exit(1);
959 
960 	tool = timerlat_init_hist(params);
961 	if (!tool) {
962 		err_msg("Could not init osnoise hist\n");
963 		goto out_exit;
964 	}
965 
966 	retval = timerlat_hist_apply_config(tool, params);
967 	if (retval) {
968 		err_msg("Could not apply config\n");
969 		goto out_free;
970 	}
971 
972 	trace = &tool->trace;
973 
974 	retval = enable_timerlat(trace);
975 	if (retval) {
976 		err_msg("Failed to enable timerlat tracer\n");
977 		goto out_free;
978 	}
979 
980 	if (params->set_sched) {
981 		retval = set_comm_sched_attr("timerlat/", &params->sched_param);
982 		if (retval) {
983 			err_msg("Failed to set sched parameters\n");
984 			goto out_free;
985 		}
986 	}
987 
988 	if (params->cgroup && !params->user_hist) {
989 		retval = set_comm_cgroup("timerlat/", params->cgroup_name);
990 		if (!retval) {
991 			err_msg("Failed to move threads to cgroup\n");
992 			goto out_free;
993 		}
994 	}
995 
996 	if (params->dma_latency >= 0) {
997 		dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
998 		if (dma_latency_fd < 0) {
999 			err_msg("Could not set /dev/cpu_dma_latency.\n");
1000 			goto out_free;
1001 		}
1002 	}
1003 
1004 	if (params->trace_output) {
1005 		record = osnoise_init_trace_tool("timerlat");
1006 		if (!record) {
1007 			err_msg("Failed to enable the trace instance\n");
1008 			goto out_free;
1009 		}
1010 
1011 		if (params->events) {
1012 			retval = trace_events_enable(&record->trace, params->events);
1013 			if (retval)
1014 				goto out_hist;
1015 		}
1016 	}
1017 
1018 	if (!params->no_aa) {
1019 		aa = osnoise_init_tool("timerlat_aa");
1020 		if (!aa)
1021 			goto out_hist;
1022 
1023 		retval = timerlat_aa_init(aa, params->dump_tasks);
1024 		if (retval) {
1025 			err_msg("Failed to enable the auto analysis instance\n");
1026 			goto out_hist;
1027 		}
1028 
1029 		retval = enable_timerlat(&aa->trace);
1030 		if (retval) {
1031 			err_msg("Failed to enable timerlat tracer\n");
1032 			goto out_hist;
1033 		}
1034 	}
1035 
1036 	/*
1037 	 * Start the tracers here, after having set all instances.
1038 	 *
1039 	 * Let the trace instance start first for the case of hitting a stop
1040 	 * tracing while enabling other instances. The trace instance is the
1041 	 * one with most valuable information.
1042 	 */
1043 	if (params->trace_output)
1044 		trace_instance_start(&record->trace);
1045 	if (!params->no_aa)
1046 		trace_instance_start(&aa->trace);
1047 	trace_instance_start(trace);
1048 
1049 	tool->start_time = time(NULL);
1050 	timerlat_hist_set_signals(params);
1051 
1052 	if (params->user_hist) {
1053 		/* rtla asked to stop */
1054 		params_u.should_run = 1;
1055 		/* all threads left */
1056 		params_u.stopped_running = 0;
1057 
1058 		params_u.set = &params->monitored_cpus;
1059 		if (params->set_sched)
1060 			params_u.sched_param = &params->sched_param;
1061 		else
1062 			params_u.sched_param = NULL;
1063 
1064 		params_u.cgroup_name = params->cgroup_name;
1065 
1066 		retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, &params_u);
1067 		if (retval)
1068 			err_msg("Error creating timerlat user-space threads\n");
1069 	}
1070 
1071 	while (!stop_tracing) {
1072 		sleep(params->sleep_time);
1073 
1074 		retval = tracefs_iterate_raw_events(trace->tep,
1075 						    trace->inst,
1076 						    NULL,
1077 						    0,
1078 						    collect_registered_events,
1079 						    trace);
1080 		if (retval < 0) {
1081 			err_msg("Error iterating on events\n");
1082 			goto out_hist;
1083 		}
1084 
1085 		if (trace_is_off(&tool->trace, &record->trace))
1086 			break;
1087 
1088 		/* is there still any user-threads ? */
1089 		if (params->user_hist) {
1090 			if (params_u.stopped_running) {
1091 				debug_msg("timerlat user-space threads stopped!\n");
1092 				break;
1093 			}
1094 		}
1095 	}
1096 	if (params->user_hist && !params_u.stopped_running) {
1097 		params_u.should_run = 0;
1098 		sleep(1);
1099 	}
1100 
1101 	timerlat_print_stats(params, tool);
1102 
1103 	return_value = 0;
1104 
1105 	if (trace_is_off(&tool->trace, &record->trace)) {
1106 		printf("rtla timerlat hit stop tracing\n");
1107 
1108 		if (!params->no_aa)
1109 			timerlat_auto_analysis(params->stop_us, params->stop_total_us);
1110 
1111 		if (params->trace_output) {
1112 			printf("  Saving trace to %s\n", params->trace_output);
1113 			save_trace_to_file(record->trace.inst, params->trace_output);
1114 		}
1115 	}
1116 
1117 out_hist:
1118 	timerlat_aa_destroy();
1119 	if (dma_latency_fd >= 0)
1120 		close(dma_latency_fd);
1121 	trace_events_destroy(&record->trace, params->events);
1122 	params->events = NULL;
1123 out_free:
1124 	timerlat_free_histogram(tool->data);
1125 	osnoise_destroy_tool(aa);
1126 	osnoise_destroy_tool(record);
1127 	osnoise_destroy_tool(tool);
1128 	free(params);
1129 out_exit:
1130 	exit(return_value);
1131 }
1132