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 <errno.h>
15 #include <sched.h>
16 #include <pthread.h>
17
18 #include "utils.h"
19 #include "osnoise.h"
20 #include "timerlat.h"
21 #include "timerlat_aa.h"
22 #include "timerlat_u.h"
23
24 struct timerlat_top_params {
25 char *cpus;
26 cpu_set_t monitored_cpus;
27 char *trace_output;
28 char *cgroup_name;
29 unsigned long long runtime;
30 long long stop_us;
31 long long stop_total_us;
32 long long timerlat_period_us;
33 long long print_stack;
34 int sleep_time;
35 int output_divisor;
36 int duration;
37 int quiet;
38 int set_sched;
39 int dma_latency;
40 int no_aa;
41 int aa_only;
42 int dump_tasks;
43 int cgroup;
44 int hk_cpus;
45 int user_top;
46 cpu_set_t hk_cpu_set;
47 struct sched_attr sched_param;
48 struct trace_events *events;
49 };
50
51 struct timerlat_top_cpu {
52 int irq_count;
53 int thread_count;
54 int user_count;
55
56 unsigned long long cur_irq;
57 unsigned long long min_irq;
58 unsigned long long sum_irq;
59 unsigned long long max_irq;
60
61 unsigned long long cur_thread;
62 unsigned long long min_thread;
63 unsigned long long sum_thread;
64 unsigned long long max_thread;
65
66 unsigned long long cur_user;
67 unsigned long long min_user;
68 unsigned long long sum_user;
69 unsigned long long max_user;
70 };
71
72 struct timerlat_top_data {
73 struct timerlat_top_cpu *cpu_data;
74 int nr_cpus;
75 };
76
77 /*
78 * timerlat_free_top - free runtime data
79 */
80 static void
timerlat_free_top(struct timerlat_top_data * data)81 timerlat_free_top(struct timerlat_top_data *data)
82 {
83 free(data->cpu_data);
84 free(data);
85 }
86
87 /*
88 * timerlat_alloc_histogram - alloc runtime data
89 */
timerlat_alloc_top(int nr_cpus)90 static struct timerlat_top_data *timerlat_alloc_top(int nr_cpus)
91 {
92 struct timerlat_top_data *data;
93 int cpu;
94
95 data = calloc(1, sizeof(*data));
96 if (!data)
97 return NULL;
98
99 data->nr_cpus = nr_cpus;
100
101 /* one set of histograms per CPU */
102 data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus);
103 if (!data->cpu_data)
104 goto cleanup;
105
106 /* set the min to max */
107 for (cpu = 0; cpu < nr_cpus; cpu++) {
108 data->cpu_data[cpu].min_irq = ~0;
109 data->cpu_data[cpu].min_thread = ~0;
110 data->cpu_data[cpu].min_user = ~0;
111 }
112
113 return data;
114
115 cleanup:
116 timerlat_free_top(data);
117 return NULL;
118 }
119
120 /*
121 * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
122 */
123 static void
timerlat_top_update(struct osnoise_tool * tool,int cpu,unsigned long long thread,unsigned long long latency)124 timerlat_top_update(struct osnoise_tool *tool, int cpu,
125 unsigned long long thread,
126 unsigned long long latency)
127 {
128 struct timerlat_top_data *data = tool->data;
129 struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
130
131 if (!thread) {
132 cpu_data->irq_count++;
133 cpu_data->cur_irq = latency;
134 update_min(&cpu_data->min_irq, &latency);
135 update_sum(&cpu_data->sum_irq, &latency);
136 update_max(&cpu_data->max_irq, &latency);
137 } else if (thread == 1) {
138 cpu_data->thread_count++;
139 cpu_data->cur_thread = latency;
140 update_min(&cpu_data->min_thread, &latency);
141 update_sum(&cpu_data->sum_thread, &latency);
142 update_max(&cpu_data->max_thread, &latency);
143 } else {
144 cpu_data->user_count++;
145 cpu_data->cur_user = latency;
146 update_min(&cpu_data->min_user, &latency);
147 update_sum(&cpu_data->sum_user, &latency);
148 update_max(&cpu_data->max_user, &latency);
149 }
150 }
151
152 /*
153 * timerlat_top_handler - this is the handler for timerlat tracer events
154 */
155 static int
timerlat_top_handler(struct trace_seq * s,struct tep_record * record,struct tep_event * event,void * context)156 timerlat_top_handler(struct trace_seq *s, struct tep_record *record,
157 struct tep_event *event, void *context)
158 {
159 struct trace_instance *trace = context;
160 struct timerlat_top_params *params;
161 unsigned long long latency, thread;
162 struct osnoise_tool *top;
163 int cpu = record->cpu;
164
165 top = container_of(trace, struct osnoise_tool, trace);
166 params = top->params;
167
168 if (!params->aa_only) {
169 tep_get_field_val(s, event, "context", record, &thread, 1);
170 tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
171
172 timerlat_top_update(top, cpu, thread, latency);
173 }
174
175 return 0;
176 }
177
178 /*
179 * timerlat_top_header - print the header of the tool output
180 */
timerlat_top_header(struct osnoise_tool * top)181 static void timerlat_top_header(struct osnoise_tool *top)
182 {
183 struct timerlat_top_params *params = top->params;
184 struct trace_seq *s = top->trace.seq;
185 char duration[26];
186
187 get_duration(top->start_time, duration, sizeof(duration));
188
189 trace_seq_printf(s, "\033[2;37;40m");
190 trace_seq_printf(s, " Timer Latency ");
191 if (params->user_top)
192 trace_seq_printf(s, " ");
193 trace_seq_printf(s, "\033[0;0;0m");
194 trace_seq_printf(s, "\n");
195
196 trace_seq_printf(s, "%-6s | IRQ Timer Latency (%s) | Thread Timer Latency (%s)", duration,
197 params->output_divisor == 1 ? "ns" : "us",
198 params->output_divisor == 1 ? "ns" : "us");
199
200 if (params->user_top) {
201 trace_seq_printf(s, " | Ret user Timer Latency (%s)",
202 params->output_divisor == 1 ? "ns" : "us");
203 }
204
205 trace_seq_printf(s, "\n");
206 trace_seq_printf(s, "\033[2;30;47m");
207 trace_seq_printf(s, "CPU COUNT | cur min avg max | cur min avg max");
208 if (params->user_top)
209 trace_seq_printf(s, " | cur min avg max");
210 trace_seq_printf(s, "\033[0;0;0m");
211 trace_seq_printf(s, "\n");
212 }
213
214 /*
215 * timerlat_top_print - prints the output of a given CPU
216 */
timerlat_top_print(struct osnoise_tool * top,int cpu)217 static void timerlat_top_print(struct osnoise_tool *top, int cpu)
218 {
219
220 struct timerlat_top_params *params = top->params;
221 struct timerlat_top_data *data = top->data;
222 struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
223 int divisor = params->output_divisor;
224 struct trace_seq *s = top->trace.seq;
225
226 if (divisor == 0)
227 return;
228
229 /*
230 * Skip if no data is available: is this cpu offline?
231 */
232 if (!cpu_data->irq_count && !cpu_data->thread_count)
233 return;
234
235 /*
236 * Unless trace is being lost, IRQ counter is always the max.
237 */
238 trace_seq_printf(s, "%3d #%-9d |", cpu, cpu_data->irq_count);
239
240 if (!cpu_data->irq_count) {
241 trace_seq_printf(s, " - ");
242 trace_seq_printf(s, " - ");
243 trace_seq_printf(s, " - ");
244 trace_seq_printf(s, " - |");
245 } else {
246 trace_seq_printf(s, "%9llu ", cpu_data->cur_irq / params->output_divisor);
247 trace_seq_printf(s, "%9llu ", cpu_data->min_irq / params->output_divisor);
248 trace_seq_printf(s, "%9llu ", (cpu_data->sum_irq / cpu_data->irq_count) / divisor);
249 trace_seq_printf(s, "%9llu |", cpu_data->max_irq / divisor);
250 }
251
252 if (!cpu_data->thread_count) {
253 trace_seq_printf(s, " - ");
254 trace_seq_printf(s, " - ");
255 trace_seq_printf(s, " - ");
256 trace_seq_printf(s, " -\n");
257 } else {
258 trace_seq_printf(s, "%9llu ", cpu_data->cur_thread / divisor);
259 trace_seq_printf(s, "%9llu ", cpu_data->min_thread / divisor);
260 trace_seq_printf(s, "%9llu ",
261 (cpu_data->sum_thread / cpu_data->thread_count) / divisor);
262 trace_seq_printf(s, "%9llu", cpu_data->max_thread / divisor);
263 }
264
265 if (!params->user_top) {
266 trace_seq_printf(s, "\n");
267 return;
268 }
269
270 trace_seq_printf(s, " |");
271
272 if (!cpu_data->user_count) {
273 trace_seq_printf(s, " - ");
274 trace_seq_printf(s, " - ");
275 trace_seq_printf(s, " - ");
276 trace_seq_printf(s, " -\n");
277 } else {
278 trace_seq_printf(s, "%9llu ", cpu_data->cur_user / divisor);
279 trace_seq_printf(s, "%9llu ", cpu_data->min_user / divisor);
280 trace_seq_printf(s, "%9llu ",
281 (cpu_data->sum_user / cpu_data->user_count) / divisor);
282 trace_seq_printf(s, "%9llu\n", cpu_data->max_user / divisor);
283 }
284 }
285
286 /*
287 * clear_terminal - clears the output terminal
288 */
clear_terminal(struct trace_seq * seq)289 static void clear_terminal(struct trace_seq *seq)
290 {
291 if (!config_debug)
292 trace_seq_printf(seq, "\033c");
293 }
294
295 /*
296 * timerlat_print_stats - print data for all cpus
297 */
298 static void
timerlat_print_stats(struct timerlat_top_params * params,struct osnoise_tool * top)299 timerlat_print_stats(struct timerlat_top_params *params, struct osnoise_tool *top)
300 {
301 struct trace_instance *trace = &top->trace;
302 static int nr_cpus = -1;
303 int i;
304
305 if (params->aa_only)
306 return;
307
308 if (nr_cpus == -1)
309 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
310
311 if (!params->quiet)
312 clear_terminal(trace->seq);
313
314 timerlat_top_header(top);
315
316 for (i = 0; i < nr_cpus; i++) {
317 if (params->cpus && !CPU_ISSET(i, ¶ms->monitored_cpus))
318 continue;
319 timerlat_top_print(top, i);
320 }
321
322 trace_seq_do_printf(trace->seq);
323 trace_seq_reset(trace->seq);
324 }
325
326 /*
327 * timerlat_top_usage - prints timerlat top usage message
328 */
timerlat_top_usage(char * usage)329 static void timerlat_top_usage(char *usage)
330 {
331 int i;
332
333 static const char *const msg[] = {
334 "",
335 " usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
336 " [[-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
337 " [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u]",
338 "",
339 " -h/--help: print this menu",
340 " -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
341 " --aa-only us: stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)",
342 " -p/--period us: timerlat period in us",
343 " -i/--irq us: stop trace if the irq latency is higher than the argument in us",
344 " -T/--thread us: stop trace if the thread latency is higher than the argument in us",
345 " -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
346 " -c/--cpus cpus: run the tracer only on the given cpus",
347 " -H/--house-keeping cpus: run rtla control threads only on the given cpus",
348 " -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
349 " -d/--duration time[m|h|d]: duration of the session in seconds",
350 " -D/--debug: print debug info",
351 " --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
352 " -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]",
353 " -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
354 " --filter <command>: enable a trace event filter to the previous -e event",
355 " --trigger <command>: enable a trace event trigger to the previous -e event",
356 " -n/--nano: display data in nanoseconds",
357 " --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",
358 " -q/--quiet print only a summary at the end",
359 " --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
360 " -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
361 " o:prio - use SCHED_OTHER with prio",
362 " r:prio - use SCHED_RR with prio",
363 " f:prio - use SCHED_FIFO with prio",
364 " d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
365 " in nanoseconds",
366 " -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads",
367 NULL,
368 };
369
370 if (usage)
371 fprintf(stderr, "%s\n", usage);
372
373 fprintf(stderr, "rtla timerlat top: a per-cpu summary of the timer latency (version %s)\n",
374 VERSION);
375
376 for (i = 0; msg[i]; i++)
377 fprintf(stderr, "%s\n", msg[i]);
378 exit(1);
379 }
380
381 /*
382 * timerlat_top_parse_args - allocs, parse and fill the cmd line parameters
383 */
384 static struct timerlat_top_params
timerlat_top_parse_args(int argc,char ** argv)385 *timerlat_top_parse_args(int argc, char **argv)
386 {
387 struct timerlat_top_params *params;
388 struct trace_events *tevent;
389 long long auto_thresh;
390 int retval;
391 int c;
392
393 params = calloc(1, sizeof(*params));
394 if (!params)
395 exit(1);
396
397 /* disabled by default */
398 params->dma_latency = -1;
399
400 /* display data in microseconds */
401 params->output_divisor = 1000;
402
403 while (1) {
404 static struct option long_options[] = {
405 {"auto", required_argument, 0, 'a'},
406 {"cpus", required_argument, 0, 'c'},
407 {"cgroup", optional_argument, 0, 'C'},
408 {"debug", no_argument, 0, 'D'},
409 {"duration", required_argument, 0, 'd'},
410 {"event", required_argument, 0, 'e'},
411 {"help", no_argument, 0, 'h'},
412 {"house-keeping", required_argument, 0, 'H'},
413 {"irq", required_argument, 0, 'i'},
414 {"nano", no_argument, 0, 'n'},
415 {"period", required_argument, 0, 'p'},
416 {"priority", required_argument, 0, 'P'},
417 {"quiet", no_argument, 0, 'q'},
418 {"stack", required_argument, 0, 's'},
419 {"thread", required_argument, 0, 'T'},
420 {"trace", optional_argument, 0, 't'},
421 {"user-threads", no_argument, 0, 'u'},
422 {"trigger", required_argument, 0, '0'},
423 {"filter", required_argument, 0, '1'},
424 {"dma-latency", required_argument, 0, '2'},
425 {"no-aa", no_argument, 0, '3'},
426 {"dump-tasks", no_argument, 0, '4'},
427 {"aa-only", required_argument, 0, '5'},
428 {0, 0, 0, 0}
429 };
430
431 /* getopt_long stores the option index here. */
432 int option_index = 0;
433
434 c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:np:P:qs:t::T:u0:1:2:345:",
435 long_options, &option_index);
436
437 /* detect the end of the options. */
438 if (c == -1)
439 break;
440
441 switch (c) {
442 case 'a':
443 auto_thresh = get_llong_from_str(optarg);
444
445 /* set thread stop to auto_thresh */
446 params->stop_total_us = auto_thresh;
447 params->stop_us = auto_thresh;
448
449 /* get stack trace */
450 params->print_stack = auto_thresh;
451
452 /* set trace */
453 params->trace_output = "timerlat_trace.txt";
454 break;
455 case '5':
456 /* it is here because it is similar to -a */
457 auto_thresh = get_llong_from_str(optarg);
458
459 /* set thread stop to auto_thresh */
460 params->stop_total_us = auto_thresh;
461 params->stop_us = auto_thresh;
462
463 /* get stack trace */
464 params->print_stack = auto_thresh;
465
466 /* set aa_only to avoid parsing the trace */
467 params->aa_only = 1;
468 break;
469 case 'c':
470 retval = parse_cpu_set(optarg, ¶ms->monitored_cpus);
471 if (retval)
472 timerlat_top_usage("\nInvalid -c cpu list\n");
473 params->cpus = optarg;
474 break;
475 case 'C':
476 params->cgroup = 1;
477 if (!optarg) {
478 /* will inherit this cgroup */
479 params->cgroup_name = NULL;
480 } else if (*optarg == '=') {
481 /* skip the = */
482 params->cgroup_name = ++optarg;
483 }
484 break;
485 case 'D':
486 config_debug = 1;
487 break;
488 case 'd':
489 params->duration = parse_seconds_duration(optarg);
490 if (!params->duration)
491 timerlat_top_usage("Invalid -D duration\n");
492 break;
493 case 'e':
494 tevent = trace_event_alloc(optarg);
495 if (!tevent) {
496 err_msg("Error alloc trace event");
497 exit(EXIT_FAILURE);
498 }
499
500 if (params->events)
501 tevent->next = params->events;
502 params->events = tevent;
503 break;
504 case 'h':
505 case '?':
506 timerlat_top_usage(NULL);
507 break;
508 case 'H':
509 params->hk_cpus = 1;
510 retval = parse_cpu_set(optarg, ¶ms->hk_cpu_set);
511 if (retval) {
512 err_msg("Error parsing house keeping CPUs\n");
513 exit(EXIT_FAILURE);
514 }
515 break;
516 case 'i':
517 params->stop_us = get_llong_from_str(optarg);
518 break;
519 case 'n':
520 params->output_divisor = 1;
521 break;
522 case 'p':
523 params->timerlat_period_us = get_llong_from_str(optarg);
524 if (params->timerlat_period_us > 1000000)
525 timerlat_top_usage("Period longer than 1 s\n");
526 break;
527 case 'P':
528 retval = parse_prio(optarg, ¶ms->sched_param);
529 if (retval == -1)
530 timerlat_top_usage("Invalid -P priority");
531 params->set_sched = 1;
532 break;
533 case 'q':
534 params->quiet = 1;
535 break;
536 case 's':
537 params->print_stack = get_llong_from_str(optarg);
538 break;
539 case 'T':
540 params->stop_total_us = get_llong_from_str(optarg);
541 break;
542 case 't':
543 if (optarg)
544 /* skip = */
545 params->trace_output = &optarg[1];
546 else
547 params->trace_output = "timerlat_trace.txt";
548
549 break;
550 case 'u':
551 params->user_top = true;
552 break;
553 case '0': /* trigger */
554 if (params->events) {
555 retval = trace_event_add_trigger(params->events, optarg);
556 if (retval) {
557 err_msg("Error adding trigger %s\n", optarg);
558 exit(EXIT_FAILURE);
559 }
560 } else {
561 timerlat_top_usage("--trigger requires a previous -e\n");
562 }
563 break;
564 case '1': /* filter */
565 if (params->events) {
566 retval = trace_event_add_filter(params->events, optarg);
567 if (retval) {
568 err_msg("Error adding filter %s\n", optarg);
569 exit(EXIT_FAILURE);
570 }
571 } else {
572 timerlat_top_usage("--filter requires a previous -e\n");
573 }
574 break;
575 case '2': /* dma-latency */
576 params->dma_latency = get_llong_from_str(optarg);
577 if (params->dma_latency < 0 || params->dma_latency > 10000) {
578 err_msg("--dma-latency needs to be >= 0 and < 10000");
579 exit(EXIT_FAILURE);
580 }
581 break;
582 case '3': /* no-aa */
583 params->no_aa = 1;
584 break;
585 case '4':
586 params->dump_tasks = 1;
587 break;
588 default:
589 timerlat_top_usage("Invalid option");
590 }
591 }
592
593 if (geteuid()) {
594 err_msg("rtla needs root permission\n");
595 exit(EXIT_FAILURE);
596 }
597
598 /*
599 * Auto analysis only happens if stop tracing, thus:
600 */
601 if (!params->stop_us && !params->stop_total_us)
602 params->no_aa = 1;
603
604 if (params->no_aa && params->aa_only)
605 timerlat_top_usage("--no-aa and --aa-only are mutually exclusive!");
606
607 return params;
608 }
609
610 /*
611 * timerlat_top_apply_config - apply the top configs to the initialized tool
612 */
613 static int
timerlat_top_apply_config(struct osnoise_tool * top,struct timerlat_top_params * params)614 timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *params)
615 {
616 int retval;
617 int i;
618
619 if (!params->sleep_time)
620 params->sleep_time = 1;
621
622 if (params->cpus) {
623 retval = osnoise_set_cpus(top->context, params->cpus);
624 if (retval) {
625 err_msg("Failed to apply CPUs config\n");
626 goto out_err;
627 }
628 } else {
629 for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
630 CPU_SET(i, ¶ms->monitored_cpus);
631 }
632
633 if (params->stop_us) {
634 retval = osnoise_set_stop_us(top->context, params->stop_us);
635 if (retval) {
636 err_msg("Failed to set stop us\n");
637 goto out_err;
638 }
639 }
640
641 if (params->stop_total_us) {
642 retval = osnoise_set_stop_total_us(top->context, params->stop_total_us);
643 if (retval) {
644 err_msg("Failed to set stop total us\n");
645 goto out_err;
646 }
647 }
648
649
650 if (params->timerlat_period_us) {
651 retval = osnoise_set_timerlat_period_us(top->context, params->timerlat_period_us);
652 if (retval) {
653 err_msg("Failed to set timerlat period\n");
654 goto out_err;
655 }
656 }
657
658
659 if (params->print_stack) {
660 retval = osnoise_set_print_stack(top->context, params->print_stack);
661 if (retval) {
662 err_msg("Failed to set print stack\n");
663 goto out_err;
664 }
665 }
666
667 if (params->hk_cpus) {
668 retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
669 ¶ms->hk_cpu_set);
670 if (retval == -1) {
671 err_msg("Failed to set rtla to the house keeping CPUs\n");
672 goto out_err;
673 }
674 } else if (params->cpus) {
675 /*
676 * Even if the user do not set a house-keeping CPU, try to
677 * move rtla to a CPU set different to the one where the user
678 * set the workload to run.
679 *
680 * No need to check results as this is an automatic attempt.
681 */
682 auto_house_keeping(¶ms->monitored_cpus);
683 }
684
685 if (params->user_top) {
686 retval = osnoise_set_workload(top->context, 0);
687 if (retval) {
688 err_msg("Failed to set OSNOISE_WORKLOAD option\n");
689 goto out_err;
690 }
691 }
692
693 return 0;
694
695 out_err:
696 return -1;
697 }
698
699 /*
700 * timerlat_init_top - initialize a timerlat top tool with parameters
701 */
702 static struct osnoise_tool
timerlat_init_top(struct timerlat_top_params * params)703 *timerlat_init_top(struct timerlat_top_params *params)
704 {
705 struct osnoise_tool *top;
706 int nr_cpus;
707
708 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
709
710 top = osnoise_init_tool("timerlat_top");
711 if (!top)
712 return NULL;
713
714 top->data = timerlat_alloc_top(nr_cpus);
715 if (!top->data)
716 goto out_err;
717
718 top->params = params;
719
720 tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat",
721 timerlat_top_handler, top);
722
723 return top;
724
725 out_err:
726 osnoise_destroy_tool(top);
727 return NULL;
728 }
729
730 static int stop_tracing;
stop_top(int sig)731 static void stop_top(int sig)
732 {
733 stop_tracing = 1;
734 }
735
736 /*
737 * timerlat_top_set_signals - handles the signal to stop the tool
738 */
739 static void
timerlat_top_set_signals(struct timerlat_top_params * params)740 timerlat_top_set_signals(struct timerlat_top_params *params)
741 {
742 signal(SIGINT, stop_top);
743 if (params->duration) {
744 signal(SIGALRM, stop_top);
745 alarm(params->duration);
746 }
747 }
748
timerlat_top_main(int argc,char * argv[])749 int timerlat_top_main(int argc, char *argv[])
750 {
751 struct timerlat_top_params *params;
752 struct osnoise_tool *record = NULL;
753 struct timerlat_u_params params_u;
754 struct osnoise_tool *top = NULL;
755 struct osnoise_tool *aa = NULL;
756 struct trace_instance *trace;
757 int dma_latency_fd = -1;
758 pthread_t timerlat_u;
759 int return_value = 1;
760 char *max_lat;
761 int retval;
762
763 params = timerlat_top_parse_args(argc, argv);
764 if (!params)
765 exit(1);
766
767 top = timerlat_init_top(params);
768 if (!top) {
769 err_msg("Could not init osnoise top\n");
770 goto out_exit;
771 }
772
773 retval = timerlat_top_apply_config(top, params);
774 if (retval) {
775 err_msg("Could not apply config\n");
776 goto out_free;
777 }
778
779 trace = &top->trace;
780
781 retval = enable_timerlat(trace);
782 if (retval) {
783 err_msg("Failed to enable timerlat tracer\n");
784 goto out_free;
785 }
786
787 if (params->set_sched) {
788 retval = set_comm_sched_attr("timerlat/", ¶ms->sched_param);
789 if (retval) {
790 err_msg("Failed to set sched parameters\n");
791 goto out_free;
792 }
793 }
794
795 if (params->cgroup && !params->user_top) {
796 retval = set_comm_cgroup("timerlat/", params->cgroup_name);
797 if (!retval) {
798 err_msg("Failed to move threads to cgroup\n");
799 goto out_free;
800 }
801 }
802
803 if (params->dma_latency >= 0) {
804 dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
805 if (dma_latency_fd < 0) {
806 err_msg("Could not set /dev/cpu_dma_latency.\n");
807 goto out_free;
808 }
809 }
810
811 if (params->trace_output) {
812 record = osnoise_init_trace_tool("timerlat");
813 if (!record) {
814 err_msg("Failed to enable the trace instance\n");
815 goto out_free;
816 }
817
818 if (params->events) {
819 retval = trace_events_enable(&record->trace, params->events);
820 if (retval)
821 goto out_top;
822 }
823 }
824
825 if (!params->no_aa) {
826 if (params->aa_only) {
827 /* as top is not used for display, use it for aa */
828 aa = top;
829 } else {
830 /* otherwise, a new instance is needed */
831 aa = osnoise_init_tool("timerlat_aa");
832 if (!aa)
833 goto out_top;
834 }
835
836 retval = timerlat_aa_init(aa, params->dump_tasks);
837 if (retval) {
838 err_msg("Failed to enable the auto analysis instance\n");
839 goto out_top;
840 }
841
842 /* if it is re-using the main instance, there is no need to start it */
843 if (aa != top) {
844 retval = enable_timerlat(&aa->trace);
845 if (retval) {
846 err_msg("Failed to enable timerlat tracer\n");
847 goto out_top;
848 }
849 }
850 }
851
852 /*
853 * Start the tracers here, after having set all instances.
854 *
855 * Let the trace instance start first for the case of hitting a stop
856 * tracing while enabling other instances. The trace instance is the
857 * one with most valuable information.
858 */
859 if (params->trace_output)
860 trace_instance_start(&record->trace);
861 if (!params->no_aa && aa != top)
862 trace_instance_start(&aa->trace);
863 trace_instance_start(trace);
864
865 top->start_time = time(NULL);
866 timerlat_top_set_signals(params);
867
868 if (params->user_top) {
869 /* rtla asked to stop */
870 params_u.should_run = 1;
871 /* all threads left */
872 params_u.stopped_running = 0;
873
874 params_u.set = ¶ms->monitored_cpus;
875 if (params->set_sched)
876 params_u.sched_param = ¶ms->sched_param;
877 else
878 params_u.sched_param = NULL;
879
880 params_u.cgroup_name = params->cgroup_name;
881
882 retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, ¶ms_u);
883 if (retval)
884 err_msg("Error creating timerlat user-space threads\n");
885 }
886
887 while (!stop_tracing) {
888 sleep(params->sleep_time);
889
890 if (params->aa_only && !trace_is_off(&top->trace, &record->trace))
891 continue;
892
893 retval = tracefs_iterate_raw_events(trace->tep,
894 trace->inst,
895 NULL,
896 0,
897 collect_registered_events,
898 trace);
899 if (retval < 0) {
900 err_msg("Error iterating on events\n");
901 goto out_top;
902 }
903
904 if (!params->quiet)
905 timerlat_print_stats(params, top);
906
907 if (trace_is_off(&top->trace, &record->trace))
908 break;
909
910 /* is there still any user-threads ? */
911 if (params->user_top) {
912 if (params_u.stopped_running) {
913 debug_msg("timerlat user space threads stopped!\n");
914 break;
915 }
916 }
917 }
918
919 if (params->user_top && !params_u.stopped_running) {
920 params_u.should_run = 0;
921 sleep(1);
922 }
923
924 timerlat_print_stats(params, top);
925
926 return_value = 0;
927
928 if (trace_is_off(&top->trace, &record->trace)) {
929 printf("rtla timerlat hit stop tracing\n");
930
931 if (!params->no_aa)
932 timerlat_auto_analysis(params->stop_us, params->stop_total_us);
933
934 if (params->trace_output) {
935 printf(" Saving trace to %s\n", params->trace_output);
936 save_trace_to_file(record->trace.inst, params->trace_output);
937 }
938 } else if (params->aa_only) {
939 /*
940 * If the trace did not stop with --aa-only, at least print the
941 * max known latency.
942 */
943 max_lat = tracefs_instance_file_read(trace->inst, "tracing_max_latency", NULL);
944 if (max_lat) {
945 printf(" Max latency was %s\n", max_lat);
946 free(max_lat);
947 }
948 }
949
950 out_top:
951 timerlat_aa_destroy();
952 if (dma_latency_fd >= 0)
953 close(dma_latency_fd);
954 trace_events_destroy(&record->trace, params->events);
955 params->events = NULL;
956 out_free:
957 timerlat_free_top(top->data);
958 if (aa && aa != top)
959 osnoise_destroy_tool(aa);
960 osnoise_destroy_tool(record);
961 osnoise_destroy_tool(top);
962 free(params);
963 out_exit:
964 exit(return_value);
965 }
966
