xref: /linux/tools/tracing/rtla/src/timerlat_hist.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
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 	if (data->bucket_size)
182 		bucket = latency / data->bucket_size;
183 
184 	if (!context) {
185 		hist = data->hist[cpu].irq;
186 		data->hist[cpu].irq_count++;
187 		update_min(&data->hist[cpu].min_irq, &latency);
188 		update_sum(&data->hist[cpu].sum_irq, &latency);
189 		update_max(&data->hist[cpu].max_irq, &latency);
190 	} else if (context == 1) {
191 		hist = data->hist[cpu].thread;
192 		data->hist[cpu].thread_count++;
193 		update_min(&data->hist[cpu].min_thread, &latency);
194 		update_sum(&data->hist[cpu].sum_thread, &latency);
195 		update_max(&data->hist[cpu].max_thread, &latency);
196 	} else { /* user */
197 		hist = data->hist[cpu].user;
198 		data->hist[cpu].user_count++;
199 		update_min(&data->hist[cpu].min_user, &latency);
200 		update_sum(&data->hist[cpu].sum_user, &latency);
201 		update_max(&data->hist[cpu].max_user, &latency);
202 	}
203 
204 	if (bucket < entries)
205 		hist[bucket]++;
206 	else
207 		hist[entries]++;
208 }
209 
210 /*
211  * timerlat_hist_handler - this is the handler for timerlat tracer events
212  */
213 static int
214 timerlat_hist_handler(struct trace_seq *s, struct tep_record *record,
215 		     struct tep_event *event, void *data)
216 {
217 	struct trace_instance *trace = data;
218 	unsigned long long context, latency;
219 	struct osnoise_tool *tool;
220 	int cpu = record->cpu;
221 
222 	tool = container_of(trace, struct osnoise_tool, trace);
223 
224 	tep_get_field_val(s, event, "context", record, &context, 1);
225 	tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
226 
227 	timerlat_hist_update(tool, cpu, context, latency);
228 
229 	return 0;
230 }
231 
232 /*
233  * timerlat_hist_header - print the header of the tracer to the output
234  */
235 static void timerlat_hist_header(struct osnoise_tool *tool)
236 {
237 	struct timerlat_hist_params *params = tool->params;
238 	struct timerlat_hist_data *data = tool->data;
239 	struct trace_seq *s = tool->trace.seq;
240 	char duration[26];
241 	int cpu;
242 
243 	if (params->no_header)
244 		return;
245 
246 	get_duration(tool->start_time, duration, sizeof(duration));
247 	trace_seq_printf(s, "# RTLA timerlat histogram\n");
248 	trace_seq_printf(s, "# Time unit is %s (%s)\n",
249 			params->output_divisor == 1 ? "nanoseconds" : "microseconds",
250 			params->output_divisor == 1 ? "ns" : "us");
251 
252 	trace_seq_printf(s, "# Duration: %s\n", duration);
253 
254 	if (!params->no_index)
255 		trace_seq_printf(s, "Index");
256 
257 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
258 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
259 			continue;
260 
261 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
262 			continue;
263 
264 		if (!params->no_irq)
265 			trace_seq_printf(s, "   IRQ-%03d", cpu);
266 
267 		if (!params->no_thread)
268 			trace_seq_printf(s, "   Thr-%03d", cpu);
269 
270 		if (params->user_hist)
271 			trace_seq_printf(s, "   Usr-%03d", cpu);
272 	}
273 	trace_seq_printf(s, "\n");
274 
275 
276 	trace_seq_do_printf(s);
277 	trace_seq_reset(s);
278 }
279 
280 /*
281  * timerlat_print_summary - print the summary of the hist data to the output
282  */
283 static void
284 timerlat_print_summary(struct timerlat_hist_params *params,
285 		       struct trace_instance *trace,
286 		       struct timerlat_hist_data *data)
287 {
288 	int cpu;
289 
290 	if (params->no_summary)
291 		return;
292 
293 	if (!params->no_index)
294 		trace_seq_printf(trace->seq, "count:");
295 
296 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
297 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
298 			continue;
299 
300 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
301 			continue;
302 
303 		if (!params->no_irq)
304 			trace_seq_printf(trace->seq, "%9d ",
305 					data->hist[cpu].irq_count);
306 
307 		if (!params->no_thread)
308 			trace_seq_printf(trace->seq, "%9d ",
309 					data->hist[cpu].thread_count);
310 
311 		if (params->user_hist)
312 			trace_seq_printf(trace->seq, "%9d ",
313 					 data->hist[cpu].user_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].irq_count && !data->hist[cpu].thread_count)
325 			continue;
326 
327 		if (!params->no_irq)
328 			trace_seq_printf(trace->seq, "%9llu ",
329 					data->hist[cpu].min_irq);
330 
331 		if (!params->no_thread)
332 			trace_seq_printf(trace->seq, "%9llu ",
333 					data->hist[cpu].min_thread);
334 
335 		if (params->user_hist)
336 			trace_seq_printf(trace->seq, "%9llu ",
337 					data->hist[cpu].min_user);
338 	}
339 	trace_seq_printf(trace->seq, "\n");
340 
341 	if (!params->no_index)
342 		trace_seq_printf(trace->seq, "avg:  ");
343 
344 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
345 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
346 			continue;
347 
348 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
349 			continue;
350 
351 		if (!params->no_irq) {
352 			if (data->hist[cpu].irq_count)
353 				trace_seq_printf(trace->seq, "%9llu ",
354 						 data->hist[cpu].sum_irq / data->hist[cpu].irq_count);
355 			else
356 				trace_seq_printf(trace->seq, "        - ");
357 		}
358 
359 		if (!params->no_thread) {
360 			if (data->hist[cpu].thread_count)
361 				trace_seq_printf(trace->seq, "%9llu ",
362 						 data->hist[cpu].sum_thread / data->hist[cpu].thread_count);
363 			else
364 				trace_seq_printf(trace->seq, "        - ");
365 		}
366 
367 		if (params->user_hist) {
368 			if (data->hist[cpu].user_count)
369 				trace_seq_printf(trace->seq, "%9llu ",
370 						 data->hist[cpu].sum_user / data->hist[cpu].user_count);
371 			else
372 				trace_seq_printf(trace->seq, "        - ");
373 		}
374 	}
375 	trace_seq_printf(trace->seq, "\n");
376 
377 	if (!params->no_index)
378 		trace_seq_printf(trace->seq, "max:  ");
379 
380 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
381 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
382 			continue;
383 
384 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
385 			continue;
386 
387 		if (!params->no_irq)
388 			trace_seq_printf(trace->seq, "%9llu ",
389 					data->hist[cpu].max_irq);
390 
391 		if (!params->no_thread)
392 			trace_seq_printf(trace->seq, "%9llu ",
393 					data->hist[cpu].max_thread);
394 
395 		if (params->user_hist)
396 			trace_seq_printf(trace->seq, "%9llu ",
397 					data->hist[cpu].max_user);
398 	}
399 	trace_seq_printf(trace->seq, "\n");
400 	trace_seq_do_printf(trace->seq);
401 	trace_seq_reset(trace->seq);
402 }
403 
404 /*
405  * timerlat_print_stats - print data for all CPUs
406  */
407 static void
408 timerlat_print_stats(struct timerlat_hist_params *params, struct osnoise_tool *tool)
409 {
410 	struct timerlat_hist_data *data = tool->data;
411 	struct trace_instance *trace = &tool->trace;
412 	int bucket, cpu;
413 	int total;
414 
415 	timerlat_hist_header(tool);
416 
417 	for (bucket = 0; bucket < data->entries; bucket++) {
418 		total = 0;
419 
420 		if (!params->no_index)
421 			trace_seq_printf(trace->seq, "%-6d",
422 					 bucket * data->bucket_size);
423 
424 		for (cpu = 0; cpu < data->nr_cpus; cpu++) {
425 			if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
426 				continue;
427 
428 			if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
429 				continue;
430 
431 			if (!params->no_irq) {
432 				total += data->hist[cpu].irq[bucket];
433 				trace_seq_printf(trace->seq, "%9d ",
434 						data->hist[cpu].irq[bucket]);
435 			}
436 
437 			if (!params->no_thread) {
438 				total += data->hist[cpu].thread[bucket];
439 				trace_seq_printf(trace->seq, "%9d ",
440 						data->hist[cpu].thread[bucket]);
441 			}
442 
443 			if (params->user_hist) {
444 				total += data->hist[cpu].user[bucket];
445 				trace_seq_printf(trace->seq, "%9d ",
446 						data->hist[cpu].user[bucket]);
447 			}
448 
449 		}
450 
451 		if (total == 0 && !params->with_zeros) {
452 			trace_seq_reset(trace->seq);
453 			continue;
454 		}
455 
456 		trace_seq_printf(trace->seq, "\n");
457 		trace_seq_do_printf(trace->seq);
458 		trace_seq_reset(trace->seq);
459 	}
460 
461 	if (!params->no_index)
462 		trace_seq_printf(trace->seq, "over: ");
463 
464 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
465 		if (params->cpus && !CPU_ISSET(cpu, &params->monitored_cpus))
466 			continue;
467 
468 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
469 			continue;
470 
471 		if (!params->no_irq)
472 			trace_seq_printf(trace->seq, "%9d ",
473 					 data->hist[cpu].irq[data->entries]);
474 
475 		if (!params->no_thread)
476 			trace_seq_printf(trace->seq, "%9d ",
477 					 data->hist[cpu].thread[data->entries]);
478 
479 		if (params->user_hist)
480 			trace_seq_printf(trace->seq, "%9d ",
481 					 data->hist[cpu].user[data->entries]);
482 	}
483 	trace_seq_printf(trace->seq, "\n");
484 	trace_seq_do_printf(trace->seq);
485 	trace_seq_reset(trace->seq);
486 
487 	timerlat_print_summary(params, trace, data);
488 }
489 
490 /*
491  * timerlat_hist_usage - prints timerlat top usage message
492  */
493 static void timerlat_hist_usage(char *usage)
494 {
495 	int i;
496 
497 	char *msg[] = {
498 		"",
499 		"  usage: [rtla] timerlat hist [-h] [-q] [-d s] [-D] [-n] [-a us] [-p us] [-i us] [-T us] [-s us] \\",
500 		"         [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
501 		"	  [-P priority] [-E N] [-b N] [--no-irq] [--no-thread] [--no-header] [--no-summary] \\",
502 		"	  [--no-index] [--with-zeros] [--dma-latency us] [-C[=cgroup_name]] [--no-aa] [--dump-task] [-u]",
503 		"",
504 		"	  -h/--help: print this menu",
505 		"	  -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
506 		"	  -p/--period us: timerlat period in us",
507 		"	  -i/--irq us: stop trace if the irq latency is higher than the argument in us",
508 		"	  -T/--thread us: stop trace if the thread latency is higher than the argument in us",
509 		"	  -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
510 		"	  -c/--cpus cpus: run the tracer only on the given cpus",
511 		"	  -H/--house-keeping cpus: run rtla control threads only on the given cpus",
512 		"	  -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
513 		"	  -d/--duration time[m|h|d]: duration of the session in seconds",
514 		"	     --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
515 		"	  -D/--debug: print debug info",
516 		"	  -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]",
517 		"	  -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
518 		"	     --filter <filter>: enable a trace event filter to the previous -e event",
519 		"	     --trigger <trigger>: enable a trace event trigger to the previous -e event",
520 		"	  -n/--nano: display data in nanoseconds",
521 		"	     --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",
522 		"	  -b/--bucket-size N: set the histogram bucket size (default 1)",
523 		"	  -E/--entries N: set the number of entries of the histogram (default 256)",
524 		"	     --no-irq: ignore IRQ latencies",
525 		"	     --no-thread: ignore thread latencies",
526 		"	     --no-header: do not print header",
527 		"	     --no-summary: do not print summary",
528 		"	     --no-index: do not print index",
529 		"	     --with-zeros: print zero only entries",
530 		"	     --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
531 		"	  -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
532 		"		o:prio - use SCHED_OTHER with prio",
533 		"		r:prio - use SCHED_RR with prio",
534 		"		f:prio - use SCHED_FIFO with prio",
535 		"		d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
536 		"						       in nanoseconds",
537 		"	  -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads",
538 		NULL,
539 	};
540 
541 	if (usage)
542 		fprintf(stderr, "%s\n", usage);
543 
544 	fprintf(stderr, "rtla timerlat hist: a per-cpu histogram of the timer latency (version %s)\n",
545 			VERSION);
546 
547 	for (i = 0; msg[i]; i++)
548 		fprintf(stderr, "%s\n", msg[i]);
549 	exit(1);
550 }
551 
552 /*
553  * timerlat_hist_parse_args - allocs, parse and fill the cmd line parameters
554  */
555 static struct timerlat_hist_params
556 *timerlat_hist_parse_args(int argc, char *argv[])
557 {
558 	struct timerlat_hist_params *params;
559 	struct trace_events *tevent;
560 	int auto_thresh;
561 	int retval;
562 	int c;
563 
564 	params = calloc(1, sizeof(*params));
565 	if (!params)
566 		exit(1);
567 
568 	/* disabled by default */
569 	params->dma_latency = -1;
570 
571 	/* display data in microseconds */
572 	params->output_divisor = 1000;
573 	params->bucket_size = 1;
574 	params->entries = 256;
575 
576 	while (1) {
577 		static struct option long_options[] = {
578 			{"auto",		required_argument,	0, 'a'},
579 			{"cpus",		required_argument,	0, 'c'},
580 			{"cgroup",		optional_argument,	0, 'C'},
581 			{"bucket-size",		required_argument,	0, 'b'},
582 			{"debug",		no_argument,		0, 'D'},
583 			{"entries",		required_argument,	0, 'E'},
584 			{"duration",		required_argument,	0, 'd'},
585 			{"house-keeping",	required_argument,	0, 'H'},
586 			{"help",		no_argument,		0, 'h'},
587 			{"irq",			required_argument,	0, 'i'},
588 			{"nano",		no_argument,		0, 'n'},
589 			{"period",		required_argument,	0, 'p'},
590 			{"priority",		required_argument,	0, 'P'},
591 			{"stack",		required_argument,	0, 's'},
592 			{"thread",		required_argument,	0, 'T'},
593 			{"trace",		optional_argument,	0, 't'},
594 			{"user-threads",	no_argument,		0, 'u'},
595 			{"event",		required_argument,	0, 'e'},
596 			{"no-irq",		no_argument,		0, '0'},
597 			{"no-thread",		no_argument,		0, '1'},
598 			{"no-header",		no_argument,		0, '2'},
599 			{"no-summary",		no_argument,		0, '3'},
600 			{"no-index",		no_argument,		0, '4'},
601 			{"with-zeros",		no_argument,		0, '5'},
602 			{"trigger",		required_argument,	0, '6'},
603 			{"filter",		required_argument,	0, '7'},
604 			{"dma-latency",		required_argument,	0, '8'},
605 			{"no-aa",		no_argument,		0, '9'},
606 			{"dump-task",		no_argument,		0, '\1'},
607 			{0, 0, 0, 0}
608 		};
609 
610 		/* getopt_long stores the option index here. */
611 		int option_index = 0;
612 
613 		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:u0123456:7:8:9\1",
614 				 long_options, &option_index);
615 
616 		/* detect the end of the options. */
617 		if (c == -1)
618 			break;
619 
620 		switch (c) {
621 		case 'a':
622 			auto_thresh = get_llong_from_str(optarg);
623 
624 			/* set thread stop to auto_thresh */
625 			params->stop_total_us = auto_thresh;
626 			params->stop_us = auto_thresh;
627 
628 			/* get stack trace */
629 			params->print_stack = auto_thresh;
630 
631 			/* set trace */
632 			params->trace_output = "timerlat_trace.txt";
633 
634 			break;
635 		case 'c':
636 			retval = parse_cpu_set(optarg, &params->monitored_cpus);
637 			if (retval)
638 				timerlat_hist_usage("\nInvalid -c cpu list\n");
639 			params->cpus = optarg;
640 			break;
641 		case 'C':
642 			params->cgroup = 1;
643 			if (!optarg) {
644 				/* will inherit this cgroup */
645 				params->cgroup_name = NULL;
646 			} else if (*optarg == '=') {
647 				/* skip the = */
648 				params->cgroup_name = ++optarg;
649 			}
650 			break;
651 		case 'b':
652 			params->bucket_size = get_llong_from_str(optarg);
653 			if ((params->bucket_size == 0) || (params->bucket_size >= 1000000))
654 				timerlat_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
655 			break;
656 		case 'D':
657 			config_debug = 1;
658 			break;
659 		case 'd':
660 			params->duration = parse_seconds_duration(optarg);
661 			if (!params->duration)
662 				timerlat_hist_usage("Invalid -D duration\n");
663 			break;
664 		case 'e':
665 			tevent = trace_event_alloc(optarg);
666 			if (!tevent) {
667 				err_msg("Error alloc trace event");
668 				exit(EXIT_FAILURE);
669 			}
670 
671 			if (params->events)
672 				tevent->next = params->events;
673 
674 			params->events = tevent;
675 			break;
676 		case 'E':
677 			params->entries = get_llong_from_str(optarg);
678 			if ((params->entries < 10) || (params->entries > 9999999))
679 					timerlat_hist_usage("Entries must be > 10 and < 9999999\n");
680 			break;
681 		case 'h':
682 		case '?':
683 			timerlat_hist_usage(NULL);
684 			break;
685 		case 'H':
686 			params->hk_cpus = 1;
687 			retval = parse_cpu_set(optarg, &params->hk_cpu_set);
688 			if (retval) {
689 				err_msg("Error parsing house keeping CPUs\n");
690 				exit(EXIT_FAILURE);
691 			}
692 			break;
693 		case 'i':
694 			params->stop_us = get_llong_from_str(optarg);
695 			break;
696 		case 'n':
697 			params->output_divisor = 1;
698 			break;
699 		case 'p':
700 			params->timerlat_period_us = get_llong_from_str(optarg);
701 			if (params->timerlat_period_us > 1000000)
702 				timerlat_hist_usage("Period longer than 1 s\n");
703 			break;
704 		case 'P':
705 			retval = parse_prio(optarg, &params->sched_param);
706 			if (retval == -1)
707 				timerlat_hist_usage("Invalid -P priority");
708 			params->set_sched = 1;
709 			break;
710 		case 's':
711 			params->print_stack = get_llong_from_str(optarg);
712 			break;
713 		case 'T':
714 			params->stop_total_us = get_llong_from_str(optarg);
715 			break;
716 		case 't':
717 			if (optarg)
718 				/* skip = */
719 				params->trace_output = &optarg[1];
720 			else
721 				params->trace_output = "timerlat_trace.txt";
722 			break;
723 		case 'u':
724 			params->user_hist = 1;
725 			break;
726 		case '0': /* no irq */
727 			params->no_irq = 1;
728 			break;
729 		case '1': /* no thread */
730 			params->no_thread = 1;
731 			break;
732 		case '2': /* no header */
733 			params->no_header = 1;
734 			break;
735 		case '3': /* no summary */
736 			params->no_summary = 1;
737 			break;
738 		case '4': /* no index */
739 			params->no_index = 1;
740 			break;
741 		case '5': /* with zeros */
742 			params->with_zeros = 1;
743 			break;
744 		case '6': /* trigger */
745 			if (params->events) {
746 				retval = trace_event_add_trigger(params->events, optarg);
747 				if (retval) {
748 					err_msg("Error adding trigger %s\n", optarg);
749 					exit(EXIT_FAILURE);
750 				}
751 			} else {
752 				timerlat_hist_usage("--trigger requires a previous -e\n");
753 			}
754 			break;
755 		case '7': /* filter */
756 			if (params->events) {
757 				retval = trace_event_add_filter(params->events, optarg);
758 				if (retval) {
759 					err_msg("Error adding filter %s\n", optarg);
760 					exit(EXIT_FAILURE);
761 				}
762 			} else {
763 				timerlat_hist_usage("--filter requires a previous -e\n");
764 			}
765 			break;
766 		case '8':
767 			params->dma_latency = get_llong_from_str(optarg);
768 			if (params->dma_latency < 0 || params->dma_latency > 10000) {
769 				err_msg("--dma-latency needs to be >= 0 and < 10000");
770 				exit(EXIT_FAILURE);
771 			}
772 			break;
773 		case '9':
774 			params->no_aa = 1;
775 			break;
776 		case '\1':
777 			params->dump_tasks = 1;
778 			break;
779 		default:
780 			timerlat_hist_usage("Invalid option");
781 		}
782 	}
783 
784 	if (geteuid()) {
785 		err_msg("rtla needs root permission\n");
786 		exit(EXIT_FAILURE);
787 	}
788 
789 	if (params->no_irq && params->no_thread)
790 		timerlat_hist_usage("no-irq and no-thread set, there is nothing to do here");
791 
792 	if (params->no_index && !params->with_zeros)
793 		timerlat_hist_usage("no-index set with with-zeros is not set - it does not make sense");
794 
795 	/*
796 	 * Auto analysis only happens if stop tracing, thus:
797 	 */
798 	if (!params->stop_us && !params->stop_total_us)
799 		params->no_aa = 1;
800 
801 	return params;
802 }
803 
804 /*
805  * timerlat_hist_apply_config - apply the hist configs to the initialized tool
806  */
807 static int
808 timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_params *params)
809 {
810 	int retval, i;
811 
812 	if (!params->sleep_time)
813 		params->sleep_time = 1;
814 
815 	if (params->cpus) {
816 		retval = osnoise_set_cpus(tool->context, params->cpus);
817 		if (retval) {
818 			err_msg("Failed to apply CPUs config\n");
819 			goto out_err;
820 		}
821 	} else {
822 		for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
823 			CPU_SET(i, &params->monitored_cpus);
824 	}
825 
826 	if (params->stop_us) {
827 		retval = osnoise_set_stop_us(tool->context, params->stop_us);
828 		if (retval) {
829 			err_msg("Failed to set stop us\n");
830 			goto out_err;
831 		}
832 	}
833 
834 	if (params->stop_total_us) {
835 		retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
836 		if (retval) {
837 			err_msg("Failed to set stop total us\n");
838 			goto out_err;
839 		}
840 	}
841 
842 	if (params->timerlat_period_us) {
843 		retval = osnoise_set_timerlat_period_us(tool->context, params->timerlat_period_us);
844 		if (retval) {
845 			err_msg("Failed to set timerlat period\n");
846 			goto out_err;
847 		}
848 	}
849 
850 	if (params->print_stack) {
851 		retval = osnoise_set_print_stack(tool->context, params->print_stack);
852 		if (retval) {
853 			err_msg("Failed to set print stack\n");
854 			goto out_err;
855 		}
856 	}
857 
858 	if (params->hk_cpus) {
859 		retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
860 					   &params->hk_cpu_set);
861 		if (retval == -1) {
862 			err_msg("Failed to set rtla to the house keeping CPUs\n");
863 			goto out_err;
864 		}
865 	} else if (params->cpus) {
866 		/*
867 		 * Even if the user do not set a house-keeping CPU, try to
868 		 * move rtla to a CPU set different to the one where the user
869 		 * set the workload to run.
870 		 *
871 		 * No need to check results as this is an automatic attempt.
872 		 */
873 		auto_house_keeping(&params->monitored_cpus);
874 	}
875 
876 	if (params->user_hist) {
877 		retval = osnoise_set_workload(tool->context, 0);
878 		if (retval) {
879 			err_msg("Failed to set OSNOISE_WORKLOAD option\n");
880 			goto out_err;
881 		}
882 	}
883 
884 	return 0;
885 
886 out_err:
887 	return -1;
888 }
889 
890 /*
891  * timerlat_init_hist - initialize a timerlat hist tool with parameters
892  */
893 static struct osnoise_tool
894 *timerlat_init_hist(struct timerlat_hist_params *params)
895 {
896 	struct osnoise_tool *tool;
897 	int nr_cpus;
898 
899 	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
900 
901 	tool = osnoise_init_tool("timerlat_hist");
902 	if (!tool)
903 		return NULL;
904 
905 	tool->data = timerlat_alloc_histogram(nr_cpus, params->entries, params->bucket_size);
906 	if (!tool->data)
907 		goto out_err;
908 
909 	tool->params = params;
910 
911 	tep_register_event_handler(tool->trace.tep, -1, "ftrace", "timerlat",
912 				   timerlat_hist_handler, tool);
913 
914 	return tool;
915 
916 out_err:
917 	osnoise_destroy_tool(tool);
918 	return NULL;
919 }
920 
921 static int stop_tracing;
922 static void stop_hist(int sig)
923 {
924 	stop_tracing = 1;
925 }
926 
927 /*
928  * timerlat_hist_set_signals - handles the signal to stop the tool
929  */
930 static void
931 timerlat_hist_set_signals(struct timerlat_hist_params *params)
932 {
933 	signal(SIGINT, stop_hist);
934 	if (params->duration) {
935 		signal(SIGALRM, stop_hist);
936 		alarm(params->duration);
937 	}
938 }
939 
940 int timerlat_hist_main(int argc, char *argv[])
941 {
942 	struct timerlat_hist_params *params;
943 	struct osnoise_tool *record = NULL;
944 	struct timerlat_u_params params_u;
945 	struct osnoise_tool *tool = NULL;
946 	struct osnoise_tool *aa = NULL;
947 	struct trace_instance *trace;
948 	int dma_latency_fd = -1;
949 	int return_value = 1;
950 	pthread_t timerlat_u;
951 	int retval;
952 
953 	params = timerlat_hist_parse_args(argc, argv);
954 	if (!params)
955 		exit(1);
956 
957 	tool = timerlat_init_hist(params);
958 	if (!tool) {
959 		err_msg("Could not init osnoise hist\n");
960 		goto out_exit;
961 	}
962 
963 	retval = timerlat_hist_apply_config(tool, params);
964 	if (retval) {
965 		err_msg("Could not apply config\n");
966 		goto out_free;
967 	}
968 
969 	trace = &tool->trace;
970 
971 	retval = enable_timerlat(trace);
972 	if (retval) {
973 		err_msg("Failed to enable timerlat tracer\n");
974 		goto out_free;
975 	}
976 
977 	if (params->set_sched) {
978 		retval = set_comm_sched_attr("timerlat/", &params->sched_param);
979 		if (retval) {
980 			err_msg("Failed to set sched parameters\n");
981 			goto out_free;
982 		}
983 	}
984 
985 	if (params->cgroup && !params->user_hist) {
986 		retval = set_comm_cgroup("timerlat/", params->cgroup_name);
987 		if (!retval) {
988 			err_msg("Failed to move threads to cgroup\n");
989 			goto out_free;
990 		}
991 	}
992 
993 	if (params->dma_latency >= 0) {
994 		dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
995 		if (dma_latency_fd < 0) {
996 			err_msg("Could not set /dev/cpu_dma_latency.\n");
997 			goto out_free;
998 		}
999 	}
1000 
1001 	if (params->trace_output) {
1002 		record = osnoise_init_trace_tool("timerlat");
1003 		if (!record) {
1004 			err_msg("Failed to enable the trace instance\n");
1005 			goto out_free;
1006 		}
1007 
1008 		if (params->events) {
1009 			retval = trace_events_enable(&record->trace, params->events);
1010 			if (retval)
1011 				goto out_hist;
1012 		}
1013 	}
1014 
1015 	if (!params->no_aa) {
1016 		aa = osnoise_init_tool("timerlat_aa");
1017 		if (!aa)
1018 			goto out_hist;
1019 
1020 		retval = timerlat_aa_init(aa, params->dump_tasks);
1021 		if (retval) {
1022 			err_msg("Failed to enable the auto analysis instance\n");
1023 			goto out_hist;
1024 		}
1025 
1026 		retval = enable_timerlat(&aa->trace);
1027 		if (retval) {
1028 			err_msg("Failed to enable timerlat tracer\n");
1029 			goto out_hist;
1030 		}
1031 	}
1032 
1033 	/*
1034 	 * Start the tracers here, after having set all instances.
1035 	 *
1036 	 * Let the trace instance start first for the case of hitting a stop
1037 	 * tracing while enabling other instances. The trace instance is the
1038 	 * one with most valuable information.
1039 	 */
1040 	if (params->trace_output)
1041 		trace_instance_start(&record->trace);
1042 	if (!params->no_aa)
1043 		trace_instance_start(&aa->trace);
1044 	trace_instance_start(trace);
1045 
1046 	tool->start_time = time(NULL);
1047 	timerlat_hist_set_signals(params);
1048 
1049 	if (params->user_hist) {
1050 		/* rtla asked to stop */
1051 		params_u.should_run = 1;
1052 		/* all threads left */
1053 		params_u.stopped_running = 0;
1054 
1055 		params_u.set = &params->monitored_cpus;
1056 		if (params->set_sched)
1057 			params_u.sched_param = &params->sched_param;
1058 		else
1059 			params_u.sched_param = NULL;
1060 
1061 		params_u.cgroup_name = params->cgroup_name;
1062 
1063 		retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, &params_u);
1064 		if (retval)
1065 			err_msg("Error creating timerlat user-space threads\n");
1066 	}
1067 
1068 	while (!stop_tracing) {
1069 		sleep(params->sleep_time);
1070 
1071 		retval = tracefs_iterate_raw_events(trace->tep,
1072 						    trace->inst,
1073 						    NULL,
1074 						    0,
1075 						    collect_registered_events,
1076 						    trace);
1077 		if (retval < 0) {
1078 			err_msg("Error iterating on events\n");
1079 			goto out_hist;
1080 		}
1081 
1082 		if (trace_is_off(&tool->trace, &record->trace))
1083 			break;
1084 
1085 		/* is there still any user-threads ? */
1086 		if (params->user_hist) {
1087 			if (params_u.stopped_running) {
1088 				debug_msg("timerlat user-space threads stopped!\n");
1089 				break;
1090 			}
1091 		}
1092 	}
1093 	if (params->user_hist && !params_u.stopped_running) {
1094 		params_u.should_run = 0;
1095 		sleep(1);
1096 	}
1097 
1098 	timerlat_print_stats(params, tool);
1099 
1100 	return_value = 0;
1101 
1102 	if (trace_is_off(&tool->trace, &record->trace)) {
1103 		printf("rtla timerlat hit stop tracing\n");
1104 
1105 		if (!params->no_aa)
1106 			timerlat_auto_analysis(params->stop_us, params->stop_total_us);
1107 
1108 		if (params->trace_output) {
1109 			printf("  Saving trace to %s\n", params->trace_output);
1110 			save_trace_to_file(record->trace.inst, params->trace_output);
1111 		}
1112 	}
1113 
1114 out_hist:
1115 	timerlat_aa_destroy();
1116 	if (dma_latency_fd >= 0)
1117 		close(dma_latency_fd);
1118 	trace_events_destroy(&record->trace, params->events);
1119 	params->events = NULL;
1120 out_free:
1121 	timerlat_free_histogram(tool->data);
1122 	osnoise_destroy_tool(aa);
1123 	osnoise_destroy_tool(record);
1124 	osnoise_destroy_tool(tool);
1125 	free(params);
1126 out_exit:
1127 	exit(return_value);
1128 }
1129