xref: /linux/tools/tracing/rtla/src/timerlat_hist.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
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_workload;
43 	int			user_hist;
44 	cpu_set_t		hk_cpu_set;
45 	struct sched_attr	sched_param;
46 	struct trace_events	*events;
47 	char			no_irq;
48 	char			no_thread;
49 	char			no_header;
50 	char			no_summary;
51 	char			no_index;
52 	char			with_zeros;
53 	int			bucket_size;
54 	int			entries;
55 };
56 
57 struct timerlat_hist_cpu {
58 	int			*irq;
59 	int			*thread;
60 	int			*user;
61 
62 	int			irq_count;
63 	int			thread_count;
64 	int			user_count;
65 
66 	unsigned long long	min_irq;
67 	unsigned long long	sum_irq;
68 	unsigned long long	max_irq;
69 
70 	unsigned long long	min_thread;
71 	unsigned long long	sum_thread;
72 	unsigned long long	max_thread;
73 
74 	unsigned long long	min_user;
75 	unsigned long long	sum_user;
76 	unsigned long long	max_user;
77 };
78 
79 struct timerlat_hist_data {
80 	struct timerlat_hist_cpu	*hist;
81 	int				entries;
82 	int				bucket_size;
83 	int				nr_cpus;
84 };
85 
86 /*
87  * timerlat_free_histogram - free runtime data
88  */
89 static void
90 timerlat_free_histogram(struct timerlat_hist_data *data)
91 {
92 	int cpu;
93 
94 	/* one histogram for IRQ and one for thread, per CPU */
95 	for (cpu = 0; cpu < data->nr_cpus; cpu++) {
96 		if (data->hist[cpu].irq)
97 			free(data->hist[cpu].irq);
98 
99 		if (data->hist[cpu].thread)
100 			free(data->hist[cpu].thread);
101 
102 		if (data->hist[cpu].user)
103 			free(data->hist[cpu].user);
104 
105 	}
106 
107 	/* one set of histograms per CPU */
108 	if (data->hist)
109 		free(data->hist);
110 
111 	free(data);
112 }
113 
114 /*
115  * timerlat_alloc_histogram - alloc runtime data
116  */
117 static struct timerlat_hist_data
118 *timerlat_alloc_histogram(int nr_cpus, int entries, int bucket_size)
119 {
120 	struct timerlat_hist_data *data;
121 	int cpu;
122 
123 	data = calloc(1, sizeof(*data));
124 	if (!data)
125 		return NULL;
126 
127 	data->entries = entries;
128 	data->bucket_size = bucket_size;
129 	data->nr_cpus = nr_cpus;
130 
131 	/* one set of histograms per CPU */
132 	data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
133 	if (!data->hist)
134 		goto cleanup;
135 
136 	/* one histogram for IRQ and one for thread, per cpu */
137 	for (cpu = 0; cpu < nr_cpus; cpu++) {
138 		data->hist[cpu].irq = calloc(1, sizeof(*data->hist->irq) * (entries + 1));
139 		if (!data->hist[cpu].irq)
140 			goto cleanup;
141 
142 		data->hist[cpu].thread = calloc(1, sizeof(*data->hist->thread) * (entries + 1));
143 		if (!data->hist[cpu].thread)
144 			goto cleanup;
145 
146 		data->hist[cpu].user = calloc(1, sizeof(*data->hist->user) * (entries + 1));
147 		if (!data->hist[cpu].user)
148 			goto cleanup;
149 	}
150 
151 	/* set the min to max */
152 	for (cpu = 0; cpu < nr_cpus; cpu++) {
153 		data->hist[cpu].min_irq = ~0;
154 		data->hist[cpu].min_thread = ~0;
155 		data->hist[cpu].min_user = ~0;
156 	}
157 
158 	return data;
159 
160 cleanup:
161 	timerlat_free_histogram(data);
162 	return NULL;
163 }
164 
165 /*
166  * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
167  */
168 static void
169 timerlat_hist_update(struct osnoise_tool *tool, int cpu,
170 		     unsigned long long context,
171 		     unsigned long long latency)
172 {
173 	struct timerlat_hist_params *params = tool->params;
174 	struct timerlat_hist_data *data = tool->data;
175 	int entries = data->entries;
176 	int bucket;
177 	int *hist;
178 
179 	if (params->output_divisor)
180 		latency = latency / params->output_divisor;
181 
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 		"	  -U/--user-load: enable timerlat for user-defined user-space workload",
539 		NULL,
540 	};
541 
542 	if (usage)
543 		fprintf(stderr, "%s\n", usage);
544 
545 	fprintf(stderr, "rtla timerlat hist: a per-cpu histogram of the timer latency (version %s)\n",
546 			VERSION);
547 
548 	for (i = 0; msg[i]; i++)
549 		fprintf(stderr, "%s\n", msg[i]);
550 
551 	if (usage)
552 		exit(EXIT_FAILURE);
553 
554 	exit(EXIT_SUCCESS);
555 }
556 
557 /*
558  * timerlat_hist_parse_args - allocs, parse and fill the cmd line parameters
559  */
560 static struct timerlat_hist_params
561 *timerlat_hist_parse_args(int argc, char *argv[])
562 {
563 	struct timerlat_hist_params *params;
564 	struct trace_events *tevent;
565 	int auto_thresh;
566 	int retval;
567 	int c;
568 
569 	params = calloc(1, sizeof(*params));
570 	if (!params)
571 		exit(1);
572 
573 	/* disabled by default */
574 	params->dma_latency = -1;
575 
576 	/* display data in microseconds */
577 	params->output_divisor = 1000;
578 	params->bucket_size = 1;
579 	params->entries = 256;
580 
581 	while (1) {
582 		static struct option long_options[] = {
583 			{"auto",		required_argument,	0, 'a'},
584 			{"cpus",		required_argument,	0, 'c'},
585 			{"cgroup",		optional_argument,	0, 'C'},
586 			{"bucket-size",		required_argument,	0, 'b'},
587 			{"debug",		no_argument,		0, 'D'},
588 			{"entries",		required_argument,	0, 'E'},
589 			{"duration",		required_argument,	0, 'd'},
590 			{"house-keeping",	required_argument,	0, 'H'},
591 			{"help",		no_argument,		0, 'h'},
592 			{"irq",			required_argument,	0, 'i'},
593 			{"nano",		no_argument,		0, 'n'},
594 			{"period",		required_argument,	0, 'p'},
595 			{"priority",		required_argument,	0, 'P'},
596 			{"stack",		required_argument,	0, 's'},
597 			{"thread",		required_argument,	0, 'T'},
598 			{"trace",		optional_argument,	0, 't'},
599 			{"user-threads",	no_argument,		0, 'u'},
600 			{"user-load",		no_argument,		0, 'U'},
601 			{"event",		required_argument,	0, 'e'},
602 			{"no-irq",		no_argument,		0, '0'},
603 			{"no-thread",		no_argument,		0, '1'},
604 			{"no-header",		no_argument,		0, '2'},
605 			{"no-summary",		no_argument,		0, '3'},
606 			{"no-index",		no_argument,		0, '4'},
607 			{"with-zeros",		no_argument,		0, '5'},
608 			{"trigger",		required_argument,	0, '6'},
609 			{"filter",		required_argument,	0, '7'},
610 			{"dma-latency",		required_argument,	0, '8'},
611 			{"no-aa",		no_argument,		0, '9'},
612 			{"dump-task",		no_argument,		0, '\1'},
613 			{0, 0, 0, 0}
614 		};
615 
616 		/* getopt_long stores the option index here. */
617 		int option_index = 0;
618 
619 		c = getopt_long(argc, argv, "a:c:C::b:d:e:E:DhH:i:np:P:s:t::T:uU0123456:7:8:9\1",
620 				 long_options, &option_index);
621 
622 		/* detect the end of the options. */
623 		if (c == -1)
624 			break;
625 
626 		switch (c) {
627 		case 'a':
628 			auto_thresh = get_llong_from_str(optarg);
629 
630 			/* set thread stop to auto_thresh */
631 			params->stop_total_us = auto_thresh;
632 			params->stop_us = auto_thresh;
633 
634 			/* get stack trace */
635 			params->print_stack = auto_thresh;
636 
637 			/* set trace */
638 			params->trace_output = "timerlat_trace.txt";
639 
640 			break;
641 		case 'c':
642 			retval = parse_cpu_set(optarg, &params->monitored_cpus);
643 			if (retval)
644 				timerlat_hist_usage("\nInvalid -c cpu list\n");
645 			params->cpus = optarg;
646 			break;
647 		case 'C':
648 			params->cgroup = 1;
649 			if (!optarg) {
650 				/* will inherit this cgroup */
651 				params->cgroup_name = NULL;
652 			} else if (*optarg == '=') {
653 				/* skip the = */
654 				params->cgroup_name = ++optarg;
655 			}
656 			break;
657 		case 'b':
658 			params->bucket_size = get_llong_from_str(optarg);
659 			if ((params->bucket_size == 0) || (params->bucket_size >= 1000000))
660 				timerlat_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
661 			break;
662 		case 'D':
663 			config_debug = 1;
664 			break;
665 		case 'd':
666 			params->duration = parse_seconds_duration(optarg);
667 			if (!params->duration)
668 				timerlat_hist_usage("Invalid -D duration\n");
669 			break;
670 		case 'e':
671 			tevent = trace_event_alloc(optarg);
672 			if (!tevent) {
673 				err_msg("Error alloc trace event");
674 				exit(EXIT_FAILURE);
675 			}
676 
677 			if (params->events)
678 				tevent->next = params->events;
679 
680 			params->events = tevent;
681 			break;
682 		case 'E':
683 			params->entries = get_llong_from_str(optarg);
684 			if ((params->entries < 10) || (params->entries > 9999999))
685 					timerlat_hist_usage("Entries must be > 10 and < 9999999\n");
686 			break;
687 		case 'h':
688 		case '?':
689 			timerlat_hist_usage(NULL);
690 			break;
691 		case 'H':
692 			params->hk_cpus = 1;
693 			retval = parse_cpu_set(optarg, &params->hk_cpu_set);
694 			if (retval) {
695 				err_msg("Error parsing house keeping CPUs\n");
696 				exit(EXIT_FAILURE);
697 			}
698 			break;
699 		case 'i':
700 			params->stop_us = get_llong_from_str(optarg);
701 			break;
702 		case 'n':
703 			params->output_divisor = 1;
704 			break;
705 		case 'p':
706 			params->timerlat_period_us = get_llong_from_str(optarg);
707 			if (params->timerlat_period_us > 1000000)
708 				timerlat_hist_usage("Period longer than 1 s\n");
709 			break;
710 		case 'P':
711 			retval = parse_prio(optarg, &params->sched_param);
712 			if (retval == -1)
713 				timerlat_hist_usage("Invalid -P priority");
714 			params->set_sched = 1;
715 			break;
716 		case 's':
717 			params->print_stack = get_llong_from_str(optarg);
718 			break;
719 		case 'T':
720 			params->stop_total_us = get_llong_from_str(optarg);
721 			break;
722 		case 't':
723 			if (optarg)
724 				/* skip = */
725 				params->trace_output = &optarg[1];
726 			else
727 				params->trace_output = "timerlat_trace.txt";
728 			break;
729 		case 'u':
730 			params->user_workload = 1;
731 			/* fallback: -u implies in -U */
732 		case 'U':
733 			params->user_hist = 1;
734 			break;
735 		case '0': /* no irq */
736 			params->no_irq = 1;
737 			break;
738 		case '1': /* no thread */
739 			params->no_thread = 1;
740 			break;
741 		case '2': /* no header */
742 			params->no_header = 1;
743 			break;
744 		case '3': /* no summary */
745 			params->no_summary = 1;
746 			break;
747 		case '4': /* no index */
748 			params->no_index = 1;
749 			break;
750 		case '5': /* with zeros */
751 			params->with_zeros = 1;
752 			break;
753 		case '6': /* trigger */
754 			if (params->events) {
755 				retval = trace_event_add_trigger(params->events, optarg);
756 				if (retval) {
757 					err_msg("Error adding trigger %s\n", optarg);
758 					exit(EXIT_FAILURE);
759 				}
760 			} else {
761 				timerlat_hist_usage("--trigger requires a previous -e\n");
762 			}
763 			break;
764 		case '7': /* filter */
765 			if (params->events) {
766 				retval = trace_event_add_filter(params->events, optarg);
767 				if (retval) {
768 					err_msg("Error adding filter %s\n", optarg);
769 					exit(EXIT_FAILURE);
770 				}
771 			} else {
772 				timerlat_hist_usage("--filter requires a previous -e\n");
773 			}
774 			break;
775 		case '8':
776 			params->dma_latency = get_llong_from_str(optarg);
777 			if (params->dma_latency < 0 || params->dma_latency > 10000) {
778 				err_msg("--dma-latency needs to be >= 0 and < 10000");
779 				exit(EXIT_FAILURE);
780 			}
781 			break;
782 		case '9':
783 			params->no_aa = 1;
784 			break;
785 		case '\1':
786 			params->dump_tasks = 1;
787 			break;
788 		default:
789 			timerlat_hist_usage("Invalid option");
790 		}
791 	}
792 
793 	if (geteuid()) {
794 		err_msg("rtla needs root permission\n");
795 		exit(EXIT_FAILURE);
796 	}
797 
798 	if (params->no_irq && params->no_thread)
799 		timerlat_hist_usage("no-irq and no-thread set, there is nothing to do here");
800 
801 	if (params->no_index && !params->with_zeros)
802 		timerlat_hist_usage("no-index set with with-zeros is not set - it does not make sense");
803 
804 	/*
805 	 * Auto analysis only happens if stop tracing, thus:
806 	 */
807 	if (!params->stop_us && !params->stop_total_us)
808 		params->no_aa = 1;
809 
810 	return params;
811 }
812 
813 /*
814  * timerlat_hist_apply_config - apply the hist configs to the initialized tool
815  */
816 static int
817 timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_params *params)
818 {
819 	int retval, i;
820 
821 	if (!params->sleep_time)
822 		params->sleep_time = 1;
823 
824 	if (params->cpus) {
825 		retval = osnoise_set_cpus(tool->context, params->cpus);
826 		if (retval) {
827 			err_msg("Failed to apply CPUs config\n");
828 			goto out_err;
829 		}
830 	} else {
831 		for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
832 			CPU_SET(i, &params->monitored_cpus);
833 	}
834 
835 	if (params->stop_us) {
836 		retval = osnoise_set_stop_us(tool->context, params->stop_us);
837 		if (retval) {
838 			err_msg("Failed to set stop us\n");
839 			goto out_err;
840 		}
841 	}
842 
843 	if (params->stop_total_us) {
844 		retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
845 		if (retval) {
846 			err_msg("Failed to set stop total us\n");
847 			goto out_err;
848 		}
849 	}
850 
851 	if (params->timerlat_period_us) {
852 		retval = osnoise_set_timerlat_period_us(tool->context, params->timerlat_period_us);
853 		if (retval) {
854 			err_msg("Failed to set timerlat period\n");
855 			goto out_err;
856 		}
857 	}
858 
859 	if (params->print_stack) {
860 		retval = osnoise_set_print_stack(tool->context, params->print_stack);
861 		if (retval) {
862 			err_msg("Failed to set print stack\n");
863 			goto out_err;
864 		}
865 	}
866 
867 	if (params->hk_cpus) {
868 		retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
869 					   &params->hk_cpu_set);
870 		if (retval == -1) {
871 			err_msg("Failed to set rtla to the house keeping CPUs\n");
872 			goto out_err;
873 		}
874 	} else if (params->cpus) {
875 		/*
876 		 * Even if the user do not set a house-keeping CPU, try to
877 		 * move rtla to a CPU set different to the one where the user
878 		 * set the workload to run.
879 		 *
880 		 * No need to check results as this is an automatic attempt.
881 		 */
882 		auto_house_keeping(&params->monitored_cpus);
883 	}
884 
885 	if (params->user_hist) {
886 		retval = osnoise_set_workload(tool->context, 0);
887 		if (retval) {
888 			err_msg("Failed to set OSNOISE_WORKLOAD option\n");
889 			goto out_err;
890 		}
891 	}
892 
893 	return 0;
894 
895 out_err:
896 	return -1;
897 }
898 
899 /*
900  * timerlat_init_hist - initialize a timerlat hist tool with parameters
901  */
902 static struct osnoise_tool
903 *timerlat_init_hist(struct timerlat_hist_params *params)
904 {
905 	struct osnoise_tool *tool;
906 	int nr_cpus;
907 
908 	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
909 
910 	tool = osnoise_init_tool("timerlat_hist");
911 	if (!tool)
912 		return NULL;
913 
914 	tool->data = timerlat_alloc_histogram(nr_cpus, params->entries, params->bucket_size);
915 	if (!tool->data)
916 		goto out_err;
917 
918 	tool->params = params;
919 
920 	tep_register_event_handler(tool->trace.tep, -1, "ftrace", "timerlat",
921 				   timerlat_hist_handler, tool);
922 
923 	return tool;
924 
925 out_err:
926 	osnoise_destroy_tool(tool);
927 	return NULL;
928 }
929 
930 static int stop_tracing;
931 static void stop_hist(int sig)
932 {
933 	stop_tracing = 1;
934 }
935 
936 /*
937  * timerlat_hist_set_signals - handles the signal to stop the tool
938  */
939 static void
940 timerlat_hist_set_signals(struct timerlat_hist_params *params)
941 {
942 	signal(SIGINT, stop_hist);
943 	if (params->duration) {
944 		signal(SIGALRM, stop_hist);
945 		alarm(params->duration);
946 	}
947 }
948 
949 int timerlat_hist_main(int argc, char *argv[])
950 {
951 	struct timerlat_hist_params *params;
952 	struct osnoise_tool *record = NULL;
953 	struct timerlat_u_params params_u;
954 	struct osnoise_tool *tool = NULL;
955 	struct osnoise_tool *aa = NULL;
956 	struct trace_instance *trace;
957 	int dma_latency_fd = -1;
958 	int return_value = 1;
959 	pthread_t timerlat_u;
960 	int retval;
961 
962 	params = timerlat_hist_parse_args(argc, argv);
963 	if (!params)
964 		exit(1);
965 
966 	tool = timerlat_init_hist(params);
967 	if (!tool) {
968 		err_msg("Could not init osnoise hist\n");
969 		goto out_exit;
970 	}
971 
972 	retval = timerlat_hist_apply_config(tool, params);
973 	if (retval) {
974 		err_msg("Could not apply config\n");
975 		goto out_free;
976 	}
977 
978 	trace = &tool->trace;
979 
980 	retval = enable_timerlat(trace);
981 	if (retval) {
982 		err_msg("Failed to enable timerlat tracer\n");
983 		goto out_free;
984 	}
985 
986 	if (params->set_sched) {
987 		retval = set_comm_sched_attr("timerlat/", &params->sched_param);
988 		if (retval) {
989 			err_msg("Failed to set sched parameters\n");
990 			goto out_free;
991 		}
992 	}
993 
994 	if (params->cgroup && !params->user_workload) {
995 		retval = set_comm_cgroup("timerlat/", params->cgroup_name);
996 		if (!retval) {
997 			err_msg("Failed to move threads to cgroup\n");
998 			goto out_free;
999 		}
1000 	}
1001 
1002 	if (params->dma_latency >= 0) {
1003 		dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
1004 		if (dma_latency_fd < 0) {
1005 			err_msg("Could not set /dev/cpu_dma_latency.\n");
1006 			goto out_free;
1007 		}
1008 	}
1009 
1010 	if (params->trace_output) {
1011 		record = osnoise_init_trace_tool("timerlat");
1012 		if (!record) {
1013 			err_msg("Failed to enable the trace instance\n");
1014 			goto out_free;
1015 		}
1016 
1017 		if (params->events) {
1018 			retval = trace_events_enable(&record->trace, params->events);
1019 			if (retval)
1020 				goto out_hist;
1021 		}
1022 	}
1023 
1024 	if (!params->no_aa) {
1025 		aa = osnoise_init_tool("timerlat_aa");
1026 		if (!aa)
1027 			goto out_hist;
1028 
1029 		retval = timerlat_aa_init(aa, params->dump_tasks);
1030 		if (retval) {
1031 			err_msg("Failed to enable the auto analysis instance\n");
1032 			goto out_hist;
1033 		}
1034 
1035 		retval = enable_timerlat(&aa->trace);
1036 		if (retval) {
1037 			err_msg("Failed to enable timerlat tracer\n");
1038 			goto out_hist;
1039 		}
1040 	}
1041 
1042 	/*
1043 	 * Start the tracers here, after having set all instances.
1044 	 *
1045 	 * Let the trace instance start first for the case of hitting a stop
1046 	 * tracing while enabling other instances. The trace instance is the
1047 	 * one with most valuable information.
1048 	 */
1049 	if (params->trace_output)
1050 		trace_instance_start(&record->trace);
1051 	if (!params->no_aa)
1052 		trace_instance_start(&aa->trace);
1053 	trace_instance_start(trace);
1054 
1055 	tool->start_time = time(NULL);
1056 	timerlat_hist_set_signals(params);
1057 
1058 	if (params->user_workload) {
1059 		/* rtla asked to stop */
1060 		params_u.should_run = 1;
1061 		/* all threads left */
1062 		params_u.stopped_running = 0;
1063 
1064 		params_u.set = &params->monitored_cpus;
1065 		if (params->set_sched)
1066 			params_u.sched_param = &params->sched_param;
1067 		else
1068 			params_u.sched_param = NULL;
1069 
1070 		params_u.cgroup_name = params->cgroup_name;
1071 
1072 		retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, &params_u);
1073 		if (retval)
1074 			err_msg("Error creating timerlat user-space threads\n");
1075 	}
1076 
1077 	while (!stop_tracing) {
1078 		sleep(params->sleep_time);
1079 
1080 		retval = tracefs_iterate_raw_events(trace->tep,
1081 						    trace->inst,
1082 						    NULL,
1083 						    0,
1084 						    collect_registered_events,
1085 						    trace);
1086 		if (retval < 0) {
1087 			err_msg("Error iterating on events\n");
1088 			goto out_hist;
1089 		}
1090 
1091 		if (trace_is_off(&tool->trace, &record->trace))
1092 			break;
1093 
1094 		/* is there still any user-threads ? */
1095 		if (params->user_workload) {
1096 			if (params_u.stopped_running) {
1097 				debug_msg("timerlat user-space threads stopped!\n");
1098 				break;
1099 			}
1100 		}
1101 	}
1102 	if (params->user_workload && !params_u.stopped_running) {
1103 		params_u.should_run = 0;
1104 		sleep(1);
1105 	}
1106 
1107 	timerlat_print_stats(params, tool);
1108 
1109 	return_value = 0;
1110 
1111 	if (trace_is_off(&tool->trace, &record->trace)) {
1112 		printf("rtla timerlat hit stop tracing\n");
1113 
1114 		if (!params->no_aa)
1115 			timerlat_auto_analysis(params->stop_us, params->stop_total_us);
1116 
1117 		if (params->trace_output) {
1118 			printf("  Saving trace to %s\n", params->trace_output);
1119 			save_trace_to_file(record->trace.inst, params->trace_output);
1120 		}
1121 	}
1122 
1123 out_hist:
1124 	timerlat_aa_destroy();
1125 	if (dma_latency_fd >= 0)
1126 		close(dma_latency_fd);
1127 	trace_events_destroy(&record->trace, params->events);
1128 	params->events = NULL;
1129 out_free:
1130 	timerlat_free_histogram(tool->data);
1131 	osnoise_destroy_tool(aa);
1132 	osnoise_destroy_tool(record);
1133 	osnoise_destroy_tool(tool);
1134 	free(params);
1135 out_exit:
1136 	exit(return_value);
1137 }
1138