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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
4 */
5
6#include <getopt.h>
7#include <stdlib.h>
8#include <string.h>
9#include <signal.h>
10#include <unistd.h>
11#include <stdio.h>
12#include <time.h>
13
14#include "utils.h"
15#include "osnoise.h"
16#include "timerlat.h"
17
18struct timerlat_hist_params {
19 char *cpus;
20 char *monitored_cpus;
21 char *trace_output;
22 unsigned long long runtime;
23 long long stop_us;
24 long long stop_total_us;
25 long long timerlat_period_us;
26 long long print_stack;
27 int sleep_time;
28 int output_divisor;
29 int duration;
30 int set_sched;
31 int dma_latency;
32 struct sched_attr sched_param;
33 struct trace_events *events;
34
35 char no_irq;
36 char no_thread;
37 char no_header;
38 char no_summary;
39 char no_index;
40 char with_zeros;
41 int bucket_size;
42 int entries;
43};
44
45struct timerlat_hist_cpu {
46 int *irq;
47 int *thread;
48
49 int irq_count;
50 int thread_count;
51
52 unsigned long long min_irq;
53 unsigned long long sum_irq;
54 unsigned long long max_irq;
55
56 unsigned long long min_thread;
57 unsigned long long sum_thread;
58 unsigned long long max_thread;
59};
60
61struct timerlat_hist_data {
62 struct timerlat_hist_cpu *hist;
63 int entries;
64 int bucket_size;
65 int nr_cpus;
66};
67
68/*
69 * timerlat_free_histogram - free runtime data
70 */
71static void
72timerlat_free_histogram(struct timerlat_hist_data *data)
73{
74 int cpu;
75
76 /* one histogram for IRQ and one for thread, per CPU */
77 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
78 if (data->hist[cpu].irq)
79 free(data->hist[cpu].irq);
80
81 if (data->hist[cpu].thread)
82 free(data->hist[cpu].thread);
83 }
84
85 /* one set of histograms per CPU */
86 if (data->hist)
87 free(data->hist);
88
89 free(data);
90}
91
92/*
93 * timerlat_alloc_histogram - alloc runtime data
94 */
95static struct timerlat_hist_data
96*timerlat_alloc_histogram(int nr_cpus, int entries, int bucket_size)
97{
98 struct timerlat_hist_data *data;
99 int cpu;
100
101 data = calloc(1, sizeof(*data));
102 if (!data)
103 return NULL;
104
105 data->entries = entries;
106 data->bucket_size = bucket_size;
107 data->nr_cpus = nr_cpus;
108
109 /* one set of histograms per CPU */
110 data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
111 if (!data->hist)
112 goto cleanup;
113
114 /* one histogram for IRQ and one for thread, per cpu */
115 for (cpu = 0; cpu < nr_cpus; cpu++) {
116 data->hist[cpu].irq = calloc(1, sizeof(*data->hist->irq) * (entries + 1));
117 if (!data->hist[cpu].irq)
118 goto cleanup;
119 data->hist[cpu].thread = calloc(1, sizeof(*data->hist->thread) * (entries + 1));
120 if (!data->hist[cpu].thread)
121 goto cleanup;
122 }
123
124 /* set the min to max */
125 for (cpu = 0; cpu < nr_cpus; cpu++) {
126 data->hist[cpu].min_irq = ~0;
127 data->hist[cpu].min_thread = ~0;
128 }
129
130 return data;
131
132cleanup:
133 timerlat_free_histogram(data);
134 return NULL;
135}
136
137/*
138 * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
139 */
140static void
141timerlat_hist_update(struct osnoise_tool *tool, int cpu,
142 unsigned long long thread,
143 unsigned long long latency)
144{
145 struct timerlat_hist_params *params = tool->params;
146 struct timerlat_hist_data *data = tool->data;
147 int entries = data->entries;
148 int bucket;
149 int *hist;
150
151 if (params->output_divisor)
152 latency = latency / params->output_divisor;
153
154 if (data->bucket_size)
155 bucket = latency / data->bucket_size;
156
157 if (!thread) {
158 hist = data->hist[cpu].irq;
159 data->hist[cpu].irq_count++;
160 update_min(&data->hist[cpu].min_irq, &latency);
161 update_sum(&data->hist[cpu].sum_irq, &latency);
162 update_max(&data->hist[cpu].max_irq, &latency);
163 } else {
164 hist = data->hist[cpu].thread;
165 data->hist[cpu].thread_count++;
166 update_min(&data->hist[cpu].min_thread, &latency);
167 update_sum(&data->hist[cpu].sum_thread, &latency);
168 update_max(&data->hist[cpu].max_thread, &latency);
169 }
170
171 if (bucket < entries)
172 hist[bucket]++;
173 else
174 hist[entries]++;
175}
176
177/*
178 * timerlat_hist_handler - this is the handler for timerlat tracer events
179 */
180static int
181timerlat_hist_handler(struct trace_seq *s, struct tep_record *record,
182 struct tep_event *event, void *data)
183{
184 struct trace_instance *trace = data;
185 unsigned long long thread, latency;
186 struct osnoise_tool *tool;
187 int cpu = record->cpu;
188
189 tool = container_of(trace, struct osnoise_tool, trace);
190
191 tep_get_field_val(s, event, "context", record, &thread, 1);
192 tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
193
194 timerlat_hist_update(tool, cpu, thread, latency);
195
196 return 0;
197}
198
199/*
200 * timerlat_hist_header - print the header of the tracer to the output
201 */
202static void timerlat_hist_header(struct osnoise_tool *tool)
203{
204 struct timerlat_hist_params *params = tool->params;
205 struct timerlat_hist_data *data = tool->data;
206 struct trace_seq *s = tool->trace.seq;
207 char duration[26];
208 int cpu;
209
210 if (params->no_header)
211 return;
212
213 get_duration(tool->start_time, duration, sizeof(duration));
214 trace_seq_printf(s, "# RTLA timerlat histogram\n");
215 trace_seq_printf(s, "# Time unit is %s (%s)\n",
216 params->output_divisor == 1 ? "nanoseconds" : "microseconds",
217 params->output_divisor == 1 ? "ns" : "us");
218
219 trace_seq_printf(s, "# Duration: %s\n", duration);
220
221 if (!params->no_index)
222 trace_seq_printf(s, "Index");
223
224 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
225 if (params->cpus && !params->monitored_cpus[cpu])
226 continue;
227
228 if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
229 continue;
230
231 if (!params->no_irq)
232 trace_seq_printf(s, " IRQ-%03d", cpu);
233
234 if (!params->no_thread)
235 trace_seq_printf(s, " Thr-%03d", cpu);
236 }
237 trace_seq_printf(s, "\n");
238
239
240 trace_seq_do_printf(s);
241 trace_seq_reset(s);
242}
243
244/*
245 * timerlat_print_summary - print the summary of the hist data to the output
246 */
247static void
248timerlat_print_summary(struct timerlat_hist_params *params,
249 struct trace_instance *trace,
250 struct timerlat_hist_data *data)
251{
252 int cpu;
253
254 if (params->no_summary)
255 return;
256
257 if (!params->no_index)
258 trace_seq_printf(trace->seq, "count:");
259
260 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
261 if (params->cpus && !params->monitored_cpus[cpu])
262 continue;
263
264 if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
265 continue;
266
267 if (!params->no_irq)
268 trace_seq_printf(trace->seq, "%9d ",
269 data->hist[cpu].irq_count);
270
271 if (!params->no_thread)
272 trace_seq_printf(trace->seq, "%9d ",
273 data->hist[cpu].thread_count);
274 }
275 trace_seq_printf(trace->seq, "\n");
276
277 if (!params->no_index)
278 trace_seq_printf(trace->seq, "min: ");
279
280 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
281 if (params->cpus && !params->monitored_cpus[cpu])
282 continue;
283
284 if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
285 continue;
286
287 if (!params->no_irq)
288 trace_seq_printf(trace->seq, "%9llu ",
289 data->hist[cpu].min_irq);
290
291 if (!params->no_thread)
292 trace_seq_printf(trace->seq, "%9llu ",
293 data->hist[cpu].min_thread);
294 }
295 trace_seq_printf(trace->seq, "\n");
296
297 if (!params->no_index)
298 trace_seq_printf(trace->seq, "avg: ");
299
300 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
301 if (params->cpus && !params->monitored_cpus[cpu])
302 continue;
303
304 if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
305 continue;
306
307 if (!params->no_irq) {
308 if (data->hist[cpu].irq_count)
309 trace_seq_printf(trace->seq, "%9llu ",
310 data->hist[cpu].sum_irq / data->hist[cpu].irq_count);
311 else
312 trace_seq_printf(trace->seq, " - ");
313 }
314
315 if (!params->no_thread) {
316 if (data->hist[cpu].thread_count)
317 trace_seq_printf(trace->seq, "%9llu ",
318 data->hist[cpu].sum_thread / data->hist[cpu].thread_count);
319 else
320 trace_seq_printf(trace->seq, " - ");
321 }
322 }
323 trace_seq_printf(trace->seq, "\n");
324
325 if (!params->no_index)
326 trace_seq_printf(trace->seq, "max: ");
327
328 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
329 if (params->cpus && !params->monitored_cpus[cpu])
330 continue;
331
332 if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
333 continue;
334
335 if (!params->no_irq)
336 trace_seq_printf(trace->seq, "%9llu ",
337 data->hist[cpu].max_irq);
338
339 if (!params->no_thread)
340 trace_seq_printf(trace->seq, "%9llu ",
341 data->hist[cpu].max_thread);
342 }
343 trace_seq_printf(trace->seq, "\n");
344 trace_seq_do_printf(trace->seq);
345 trace_seq_reset(trace->seq);
346}
347
348/*
349 * timerlat_print_stats - print data for all CPUs
350 */
351static void
352timerlat_print_stats(struct timerlat_hist_params *params, struct osnoise_tool *tool)
353{
354 struct timerlat_hist_data *data = tool->data;
355 struct trace_instance *trace = &tool->trace;
356 int bucket, cpu;
357 int total;
358
359 timerlat_hist_header(tool);
360
361 for (bucket = 0; bucket < data->entries; bucket++) {
362 total = 0;
363
364 if (!params->no_index)
365 trace_seq_printf(trace->seq, "%-6d",
366 bucket * data->bucket_size);
367
368 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
369 if (params->cpus && !params->monitored_cpus[cpu])
370 continue;
371
372 if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
373 continue;
374
375 if (!params->no_irq) {
376 total += data->hist[cpu].irq[bucket];
377 trace_seq_printf(trace->seq, "%9d ",
378 data->hist[cpu].irq[bucket]);
379 }
380
381 if (!params->no_thread) {
382 total += data->hist[cpu].thread[bucket];
383 trace_seq_printf(trace->seq, "%9d ",
384 data->hist[cpu].thread[bucket]);
385 }
386
387 }
388
389 if (total == 0 && !params->with_zeros) {
390 trace_seq_reset(trace->seq);
391 continue;
392 }
393
394 trace_seq_printf(trace->seq, "\n");
395 trace_seq_do_printf(trace->seq);
396 trace_seq_reset(trace->seq);
397 }
398
399 if (!params->no_index)
400 trace_seq_printf(trace->seq, "over: ");
401
402 for (cpu = 0; cpu < data->nr_cpus; cpu++) {
403 if (params->cpus && !params->monitored_cpus[cpu])
404 continue;
405
406 if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
407 continue;
408
409 if (!params->no_irq)
410 trace_seq_printf(trace->seq, "%9d ",
411 data->hist[cpu].irq[data->entries]);
412
413 if (!params->no_thread)
414 trace_seq_printf(trace->seq, "%9d ",
415 data->hist[cpu].thread[data->entries]);
416 }
417 trace_seq_printf(trace->seq, "\n");
418 trace_seq_do_printf(trace->seq);
419 trace_seq_reset(trace->seq);
420
421 timerlat_print_summary(params, trace, data);
422}
423
424/*
425 * timerlat_hist_usage - prints timerlat top usage message
426 */
427static void timerlat_hist_usage(char *usage)
428{
429 int i;
430
431 char *msg[] = {
432 "",
433 " usage: [rtla] timerlat hist [-h] [-q] [-d s] [-D] [-n] [-a us] [-p us] [-i us] [-T us] [-s us] \\",
434 " [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] \\",
435 " [-P priority] [-E N] [-b N] [--no-irq] [--no-thread] [--no-header] [--no-summary] \\",
436 " [--no-index] [--with-zeros] [--dma-latency us]",
437 "",
438 " -h/--help: print this menu",
439 " -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
440 " -p/--period us: timerlat period in us",
441 " -i/--irq us: stop trace if the irq latency is higher than the argument in us",
442 " -T/--thread us: stop trace if the thread latency is higher than the argument in us",
443 " -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
444 " -c/--cpus cpus: run the tracer only on the given cpus",
445 " -d/--duration time[m|h|d]: duration of the session in seconds",
446 " -D/--debug: print debug info",
447 " -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]",
448 " -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
449 " --filter <filter>: enable a trace event filter to the previous -e event",
450 " --trigger <trigger>: enable a trace event trigger to the previous -e event",
451 " -n/--nano: display data in nanoseconds",
452 " -b/--bucket-size N: set the histogram bucket size (default 1)",
453 " -E/--entries N: set the number of entries of the histogram (default 256)",
454 " --no-irq: ignore IRQ latencies",
455 " --no-thread: ignore thread latencies",
456 " --no-header: do not print header",
457 " --no-summary: do not print summary",
458 " --no-index: do not print index",
459 " --with-zeros: print zero only entries",
460 " --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
461 " -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
462 " o:prio - use SCHED_OTHER with prio",
463 " r:prio - use SCHED_RR with prio",
464 " f:prio - use SCHED_FIFO with prio",
465 " d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
466 " in nanoseconds",
467 NULL,
468 };
469
470 if (usage)
471 fprintf(stderr, "%s\n", usage);
472
473 fprintf(stderr, "rtla timerlat hist: a per-cpu histogram of the timer latency (version %s)\n",
474 VERSION);
475
476 for (i = 0; msg[i]; i++)
477 fprintf(stderr, "%s\n", msg[i]);
478 exit(1);
479}
480
481/*
482 * timerlat_hist_parse_args - allocs, parse and fill the cmd line parameters
483 */
484static struct timerlat_hist_params
485*timerlat_hist_parse_args(int argc, char *argv[])
486{
487 struct timerlat_hist_params *params;
488 struct trace_events *tevent;
489 int auto_thresh;
490 int retval;
491 int c;
492
493 params = calloc(1, sizeof(*params));
494 if (!params)
495 exit(1);
496
497 /* disabled by default */
498 params->dma_latency = -1;
499
500 /* display data in microseconds */
501 params->output_divisor = 1000;
502 params->bucket_size = 1;
503 params->entries = 256;
504
505 while (1) {
506 static struct option long_options[] = {
507 {"auto", required_argument, 0, 'a'},
508 {"cpus", required_argument, 0, 'c'},
509 {"bucket-size", required_argument, 0, 'b'},
510 {"debug", no_argument, 0, 'D'},
511 {"entries", required_argument, 0, 'E'},
512 {"duration", required_argument, 0, 'd'},
513 {"help", no_argument, 0, 'h'},
514 {"irq", required_argument, 0, 'i'},
515 {"nano", no_argument, 0, 'n'},
516 {"period", required_argument, 0, 'p'},
517 {"priority", required_argument, 0, 'P'},
518 {"stack", required_argument, 0, 's'},
519 {"thread", required_argument, 0, 'T'},
520 {"trace", optional_argument, 0, 't'},
521 {"event", required_argument, 0, 'e'},
522 {"no-irq", no_argument, 0, '0'},
523 {"no-thread", no_argument, 0, '1'},
524 {"no-header", no_argument, 0, '2'},
525 {"no-summary", no_argument, 0, '3'},
526 {"no-index", no_argument, 0, '4'},
527 {"with-zeros", no_argument, 0, '5'},
528 {"trigger", required_argument, 0, '6'},
529 {"filter", required_argument, 0, '7'},
530 {"dma-latency", required_argument, 0, '8'},
531 {0, 0, 0, 0}
532 };
533
534 /* getopt_long stores the option index here. */
535 int option_index = 0;
536
537 c = getopt_long(argc, argv, "a:c:b:d:e:E:Dhi:np:P:s:t::T:0123456:7:8:",
538 long_options, &option_index);
539
540 /* detect the end of the options. */
541 if (c == -1)
542 break;
543
544 switch (c) {
545 case 'a':
546 auto_thresh = get_llong_from_str(optarg);
547
548 /* set thread stop to auto_thresh */
549 params->stop_total_us = auto_thresh;
550
551 /* get stack trace */
552 params->print_stack = auto_thresh;
553
554 /* set trace */
555 params->trace_output = "timerlat_trace.txt";
556
557 break;
558 case 'c':
559 retval = parse_cpu_list(optarg, ¶ms->monitored_cpus);
560 if (retval)
561 timerlat_hist_usage("\nInvalid -c cpu list\n");
562 params->cpus = optarg;
563 break;
564 case 'b':
565 params->bucket_size = get_llong_from_str(optarg);
566 if ((params->bucket_size == 0) || (params->bucket_size >= 1000000))
567 timerlat_hist_usage("Bucket size needs to be > 0 and <= 1000000\n");
568 break;
569 case 'D':
570 config_debug = 1;
571 break;
572 case 'd':
573 params->duration = parse_seconds_duration(optarg);
574 if (!params->duration)
575 timerlat_hist_usage("Invalid -D duration\n");
576 break;
577 case 'e':
578 tevent = trace_event_alloc(optarg);
579 if (!tevent) {
580 err_msg("Error alloc trace event");
581 exit(EXIT_FAILURE);
582 }
583
584 if (params->events)
585 tevent->next = params->events;
586
587 params->events = tevent;
588 break;
589 case 'E':
590 params->entries = get_llong_from_str(optarg);
591 if ((params->entries < 10) || (params->entries > 9999999))
592 timerlat_hist_usage("Entries must be > 10 and < 9999999\n");
593 break;
594 case 'h':
595 case '?':
596 timerlat_hist_usage(NULL);
597 break;
598 case 'i':
599 params->stop_us = get_llong_from_str(optarg);
600 break;
601 case 'n':
602 params->output_divisor = 1;
603 break;
604 case 'p':
605 params->timerlat_period_us = get_llong_from_str(optarg);
606 if (params->timerlat_period_us > 1000000)
607 timerlat_hist_usage("Period longer than 1 s\n");
608 break;
609 case 'P':
610 retval = parse_prio(optarg, ¶ms->sched_param);
611 if (retval == -1)
612 timerlat_hist_usage("Invalid -P priority");
613 params->set_sched = 1;
614 break;
615 case 's':
616 params->print_stack = get_llong_from_str(optarg);
617 break;
618 case 'T':
619 params->stop_total_us = get_llong_from_str(optarg);
620 break;
621 case 't':
622 if (optarg)
623 /* skip = */
624 params->trace_output = &optarg[1];
625 else
626 params->trace_output = "timerlat_trace.txt";
627 break;
628 case '0': /* no irq */
629 params->no_irq = 1;
630 break;
631 case '1': /* no thread */
632 params->no_thread = 1;
633 break;
634 case '2': /* no header */
635 params->no_header = 1;
636 break;
637 case '3': /* no summary */
638 params->no_summary = 1;
639 break;
640 case '4': /* no index */
641 params->no_index = 1;
642 break;
643 case '5': /* with zeros */
644 params->with_zeros = 1;
645 break;
646 case '6': /* trigger */
647 if (params->events) {
648 retval = trace_event_add_trigger(params->events, optarg);
649 if (retval) {
650 err_msg("Error adding trigger %s\n", optarg);
651 exit(EXIT_FAILURE);
652 }
653 } else {
654 timerlat_hist_usage("--trigger requires a previous -e\n");
655 }
656 break;
657 case '7': /* filter */
658 if (params->events) {
659 retval = trace_event_add_filter(params->events, optarg);
660 if (retval) {
661 err_msg("Error adding filter %s\n", optarg);
662 exit(EXIT_FAILURE);
663 }
664 } else {
665 timerlat_hist_usage("--filter requires a previous -e\n");
666 }
667 break;
668 case '8':
669 params->dma_latency = get_llong_from_str(optarg);
670 if (params->dma_latency < 0 || params->dma_latency > 10000) {
671 err_msg("--dma-latency needs to be >= 0 and < 10000");
672 exit(EXIT_FAILURE);
673 }
674 break;
675 default:
676 timerlat_hist_usage("Invalid option");
677 }
678 }
679
680 if (geteuid()) {
681 err_msg("rtla needs root permission\n");
682 exit(EXIT_FAILURE);
683 }
684
685 if (params->no_irq && params->no_thread)
686 timerlat_hist_usage("no-irq and no-thread set, there is nothing to do here");
687
688 if (params->no_index && !params->with_zeros)
689 timerlat_hist_usage("no-index set with with-zeros is not set - it does not make sense");
690
691 return params;
692}
693
694/*
695 * timerlat_hist_apply_config - apply the hist configs to the initialized tool
696 */
697static int
698timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_params *params)
699{
700 int retval;
701
702 if (!params->sleep_time)
703 params->sleep_time = 1;
704
705 if (params->cpus) {
706 retval = osnoise_set_cpus(tool->context, params->cpus);
707 if (retval) {
708 err_msg("Failed to apply CPUs config\n");
709 goto out_err;
710 }
711 }
712
713 if (params->stop_us) {
714 retval = osnoise_set_stop_us(tool->context, params->stop_us);
715 if (retval) {
716 err_msg("Failed to set stop us\n");
717 goto out_err;
718 }
719 }
720
721 if (params->stop_total_us) {
722 retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
723 if (retval) {
724 err_msg("Failed to set stop total us\n");
725 goto out_err;
726 }
727 }
728
729 if (params->timerlat_period_us) {
730 retval = osnoise_set_timerlat_period_us(tool->context, params->timerlat_period_us);
731 if (retval) {
732 err_msg("Failed to set timerlat period\n");
733 goto out_err;
734 }
735 }
736
737 if (params->print_stack) {
738 retval = osnoise_set_print_stack(tool->context, params->print_stack);
739 if (retval) {
740 err_msg("Failed to set print stack\n");
741 goto out_err;
742 }
743 }
744
745 return 0;
746
747out_err:
748 return -1;
749}
750
751/*
752 * timerlat_init_hist - initialize a timerlat hist tool with parameters
753 */
754static struct osnoise_tool
755*timerlat_init_hist(struct timerlat_hist_params *params)
756{
757 struct osnoise_tool *tool;
758 int nr_cpus;
759
760 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
761
762 tool = osnoise_init_tool("timerlat_hist");
763 if (!tool)
764 return NULL;
765
766 tool->data = timerlat_alloc_histogram(nr_cpus, params->entries, params->bucket_size);
767 if (!tool->data)
768 goto out_err;
769
770 tool->params = params;
771
772 tep_register_event_handler(tool->trace.tep, -1, "ftrace", "timerlat",
773 timerlat_hist_handler, tool);
774
775 return tool;
776
777out_err:
778 osnoise_destroy_tool(tool);
779 return NULL;
780}
781
782static int stop_tracing;
783static void stop_hist(int sig)
784{
785 stop_tracing = 1;
786}
787
788/*
789 * timerlat_hist_set_signals - handles the signal to stop the tool
790 */
791static void
792timerlat_hist_set_signals(struct timerlat_hist_params *params)
793{
794 signal(SIGINT, stop_hist);
795 if (params->duration) {
796 signal(SIGALRM, stop_hist);
797 alarm(params->duration);
798 }
799}
800
801int timerlat_hist_main(int argc, char *argv[])
802{
803 struct timerlat_hist_params *params;
804 struct osnoise_tool *record = NULL;
805 struct osnoise_tool *tool = NULL;
806 struct trace_instance *trace;
807 int dma_latency_fd = -1;
808 int return_value = 1;
809 int retval;
810
811 params = timerlat_hist_parse_args(argc, argv);
812 if (!params)
813 exit(1);
814
815 tool = timerlat_init_hist(params);
816 if (!tool) {
817 err_msg("Could not init osnoise hist\n");
818 goto out_exit;
819 }
820
821 retval = timerlat_hist_apply_config(tool, params);
822 if (retval) {
823 err_msg("Could not apply config\n");
824 goto out_free;
825 }
826
827 trace = &tool->trace;
828
829 retval = enable_timerlat(trace);
830 if (retval) {
831 err_msg("Failed to enable timerlat tracer\n");
832 goto out_free;
833 }
834
835 if (params->set_sched) {
836 retval = set_comm_sched_attr("timerlat/", ¶ms->sched_param);
837 if (retval) {
838 err_msg("Failed to set sched parameters\n");
839 goto out_free;
840 }
841 }
842
843 if (params->dma_latency >= 0) {
844 dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
845 if (dma_latency_fd < 0) {
846 err_msg("Could not set /dev/cpu_dma_latency.\n");
847 goto out_free;
848 }
849 }
850
851 trace_instance_start(trace);
852
853 if (params->trace_output) {
854 record = osnoise_init_trace_tool("timerlat");
855 if (!record) {
856 err_msg("Failed to enable the trace instance\n");
857 goto out_free;
858 }
859
860 if (params->events) {
861 retval = trace_events_enable(&record->trace, params->events);
862 if (retval)
863 goto out_hist;
864 }
865
866 trace_instance_start(&record->trace);
867 }
868
869 tool->start_time = time(NULL);
870 timerlat_hist_set_signals(params);
871
872 while (!stop_tracing) {
873 sleep(params->sleep_time);
874
875 retval = tracefs_iterate_raw_events(trace->tep,
876 trace->inst,
877 NULL,
878 0,
879 collect_registered_events,
880 trace);
881 if (retval < 0) {
882 err_msg("Error iterating on events\n");
883 goto out_hist;
884 }
885
886 if (trace_is_off(&tool->trace, &record->trace))
887 break;
888 }
889
890 timerlat_print_stats(params, tool);
891
892 return_value = 0;
893
894 if (trace_is_off(&tool->trace, &record->trace)) {
895 printf("rtla timerlat hit stop tracing\n");
896 if (params->trace_output) {
897 printf(" Saving trace to %s\n", params->trace_output);
898 save_trace_to_file(record->trace.inst, params->trace_output);
899 }
900 }
901
902out_hist:
903 if (dma_latency_fd >= 0)
904 close(dma_latency_fd);
905 trace_events_destroy(&record->trace, params->events);
906 params->events = NULL;
907out_free:
908 timerlat_free_histogram(tool->data);
909 osnoise_destroy_tool(record);
910 osnoise_destroy_tool(tool);
911 free(params);
912out_exit:
913 exit(return_value);
914}