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 unsigned long long irq_count;
53 unsigned long long thread_count;
54 unsigned long long 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 static const char *no_value = " -";
215
216 /*
217 * timerlat_top_print - prints the output of a given CPU
218 */
timerlat_top_print(struct osnoise_tool * top,int cpu)219 static void timerlat_top_print(struct osnoise_tool *top, int cpu)
220 {
221
222 struct timerlat_top_params *params = top->params;
223 struct timerlat_top_data *data = top->data;
224 struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
225 int divisor = params->output_divisor;
226 struct trace_seq *s = top->trace.seq;
227
228 if (divisor == 0)
229 return;
230
231 /*
232 * Skip if no data is available: is this cpu offline?
233 */
234 if (!cpu_data->irq_count && !cpu_data->thread_count)
235 return;
236
237 /*
238 * Unless trace is being lost, IRQ counter is always the max.
239 */
240 trace_seq_printf(s, "%3d #%-9llu |", cpu, cpu_data->irq_count);
241
242 if (!cpu_data->irq_count) {
243 trace_seq_printf(s, "%s %s %s %s |", no_value, no_value, no_value, no_value);
244 } else {
245 trace_seq_printf(s, "%9llu ", cpu_data->cur_irq / params->output_divisor);
246 trace_seq_printf(s, "%9llu ", cpu_data->min_irq / params->output_divisor);
247 trace_seq_printf(s, "%9llu ", (cpu_data->sum_irq / cpu_data->irq_count) / divisor);
248 trace_seq_printf(s, "%9llu |", cpu_data->max_irq / divisor);
249 }
250
251 if (!cpu_data->thread_count) {
252 trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
253 } else {
254 trace_seq_printf(s, "%9llu ", cpu_data->cur_thread / divisor);
255 trace_seq_printf(s, "%9llu ", cpu_data->min_thread / divisor);
256 trace_seq_printf(s, "%9llu ",
257 (cpu_data->sum_thread / cpu_data->thread_count) / divisor);
258 trace_seq_printf(s, "%9llu", cpu_data->max_thread / divisor);
259 }
260
261 if (!params->user_top) {
262 trace_seq_printf(s, "\n");
263 return;
264 }
265
266 trace_seq_printf(s, " |");
267
268 if (!cpu_data->user_count) {
269 trace_seq_printf(s, "%s %s %s %s\n", no_value, no_value, no_value, no_value);
270 } else {
271 trace_seq_printf(s, "%9llu ", cpu_data->cur_user / divisor);
272 trace_seq_printf(s, "%9llu ", cpu_data->min_user / divisor);
273 trace_seq_printf(s, "%9llu ",
274 (cpu_data->sum_user / cpu_data->user_count) / divisor);
275 trace_seq_printf(s, "%9llu\n", cpu_data->max_user / divisor);
276 }
277 }
278
279 /*
280 * clear_terminal - clears the output terminal
281 */
clear_terminal(struct trace_seq * seq)282 static void clear_terminal(struct trace_seq *seq)
283 {
284 if (!config_debug)
285 trace_seq_printf(seq, "\033c");
286 }
287
288 /*
289 * timerlat_print_stats - print data for all cpus
290 */
291 static void
timerlat_print_stats(struct timerlat_top_params * params,struct osnoise_tool * top)292 timerlat_print_stats(struct timerlat_top_params *params, struct osnoise_tool *top)
293 {
294 struct trace_instance *trace = &top->trace;
295 static int nr_cpus = -1;
296 int i;
297
298 if (params->aa_only)
299 return;
300
301 if (nr_cpus == -1)
302 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
303
304 if (!params->quiet)
305 clear_terminal(trace->seq);
306
307 timerlat_top_header(top);
308
309 for (i = 0; i < nr_cpus; i++) {
310 if (params->cpus && !CPU_ISSET(i, ¶ms->monitored_cpus))
311 continue;
312 timerlat_top_print(top, i);
313 }
314
315 trace_seq_do_printf(trace->seq);
316 trace_seq_reset(trace->seq);
317 }
318
319 /*
320 * timerlat_top_usage - prints timerlat top usage message
321 */
timerlat_top_usage(char * usage)322 static void timerlat_top_usage(char *usage)
323 {
324 int i;
325
326 static const char *const msg[] = {
327 "",
328 " usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
329 " [[-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
330 " [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u]",
331 "",
332 " -h/--help: print this menu",
333 " -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
334 " --aa-only us: stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)",
335 " -p/--period us: timerlat period in us",
336 " -i/--irq us: stop trace if the irq latency is higher than the argument in us",
337 " -T/--thread us: stop trace if the thread latency is higher than the argument in us",
338 " -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
339 " -c/--cpus cpus: run the tracer only on the given cpus",
340 " -H/--house-keeping cpus: run rtla control threads only on the given cpus",
341 " -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
342 " -d/--duration time[s|m|h|d]: duration of the session",
343 " -D/--debug: print debug info",
344 " --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
345 " -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]",
346 " -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
347 " --filter <command>: enable a trace event filter to the previous -e event",
348 " --trigger <command>: enable a trace event trigger to the previous -e event",
349 " -n/--nano: display data in nanoseconds",
350 " --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",
351 " -q/--quiet print only a summary at the end",
352 " --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
353 " -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
354 " o:prio - use SCHED_OTHER with prio",
355 " r:prio - use SCHED_RR with prio",
356 " f:prio - use SCHED_FIFO with prio",
357 " d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
358 " in nanoseconds",
359 " -u/--user-threads: use rtla user-space threads instead of in-kernel timerlat threads",
360 NULL,
361 };
362
363 if (usage)
364 fprintf(stderr, "%s\n", usage);
365
366 fprintf(stderr, "rtla timerlat top: a per-cpu summary of the timer latency (version %s)\n",
367 VERSION);
368
369 for (i = 0; msg[i]; i++)
370 fprintf(stderr, "%s\n", msg[i]);
371
372 if (usage)
373 exit(EXIT_FAILURE);
374
375 exit(EXIT_SUCCESS);
376 }
377
378 /*
379 * timerlat_top_parse_args - allocs, parse and fill the cmd line parameters
380 */
381 static struct timerlat_top_params
timerlat_top_parse_args(int argc,char ** argv)382 *timerlat_top_parse_args(int argc, char **argv)
383 {
384 struct timerlat_top_params *params;
385 struct trace_events *tevent;
386 long long auto_thresh;
387 int retval;
388 int c;
389
390 params = calloc(1, sizeof(*params));
391 if (!params)
392 exit(1);
393
394 /* disabled by default */
395 params->dma_latency = -1;
396
397 /* display data in microseconds */
398 params->output_divisor = 1000;
399
400 while (1) {
401 static struct option long_options[] = {
402 {"auto", required_argument, 0, 'a'},
403 {"cpus", required_argument, 0, 'c'},
404 {"cgroup", optional_argument, 0, 'C'},
405 {"debug", no_argument, 0, 'D'},
406 {"duration", required_argument, 0, 'd'},
407 {"event", required_argument, 0, 'e'},
408 {"help", no_argument, 0, 'h'},
409 {"house-keeping", required_argument, 0, 'H'},
410 {"irq", required_argument, 0, 'i'},
411 {"nano", no_argument, 0, 'n'},
412 {"period", required_argument, 0, 'p'},
413 {"priority", required_argument, 0, 'P'},
414 {"quiet", no_argument, 0, 'q'},
415 {"stack", required_argument, 0, 's'},
416 {"thread", required_argument, 0, 'T'},
417 {"trace", optional_argument, 0, 't'},
418 {"user-threads", no_argument, 0, 'u'},
419 {"trigger", required_argument, 0, '0'},
420 {"filter", required_argument, 0, '1'},
421 {"dma-latency", required_argument, 0, '2'},
422 {"no-aa", no_argument, 0, '3'},
423 {"dump-tasks", no_argument, 0, '4'},
424 {"aa-only", required_argument, 0, '5'},
425 {0, 0, 0, 0}
426 };
427
428 /* getopt_long stores the option index here. */
429 int option_index = 0;
430
431 c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:np:P:qs:t::T:u0:1:2:345:",
432 long_options, &option_index);
433
434 /* detect the end of the options. */
435 if (c == -1)
436 break;
437
438 switch (c) {
439 case 'a':
440 auto_thresh = get_llong_from_str(optarg);
441
442 /* set thread stop to auto_thresh */
443 params->stop_total_us = auto_thresh;
444 params->stop_us = auto_thresh;
445
446 /* get stack trace */
447 params->print_stack = auto_thresh;
448
449 /* set trace */
450 params->trace_output = "timerlat_trace.txt";
451 break;
452 case '5':
453 /* it is here because it is similar to -a */
454 auto_thresh = get_llong_from_str(optarg);
455
456 /* set thread stop to auto_thresh */
457 params->stop_total_us = auto_thresh;
458 params->stop_us = auto_thresh;
459
460 /* get stack trace */
461 params->print_stack = auto_thresh;
462
463 /* set aa_only to avoid parsing the trace */
464 params->aa_only = 1;
465 break;
466 case 'c':
467 retval = parse_cpu_set(optarg, ¶ms->monitored_cpus);
468 if (retval)
469 timerlat_top_usage("\nInvalid -c cpu list\n");
470 params->cpus = optarg;
471 break;
472 case 'C':
473 params->cgroup = 1;
474 if (!optarg) {
475 /* will inherit this cgroup */
476 params->cgroup_name = NULL;
477 } else if (*optarg == '=') {
478 /* skip the = */
479 params->cgroup_name = ++optarg;
480 }
481 break;
482 case 'D':
483 config_debug = 1;
484 break;
485 case 'd':
486 params->duration = parse_seconds_duration(optarg);
487 if (!params->duration)
488 timerlat_top_usage("Invalid -d duration\n");
489 break;
490 case 'e':
491 tevent = trace_event_alloc(optarg);
492 if (!tevent) {
493 err_msg("Error alloc trace event");
494 exit(EXIT_FAILURE);
495 }
496
497 if (params->events)
498 tevent->next = params->events;
499 params->events = tevent;
500 break;
501 case 'h':
502 case '?':
503 timerlat_top_usage(NULL);
504 break;
505 case 'H':
506 params->hk_cpus = 1;
507 retval = parse_cpu_set(optarg, ¶ms->hk_cpu_set);
508 if (retval) {
509 err_msg("Error parsing house keeping CPUs\n");
510 exit(EXIT_FAILURE);
511 }
512 break;
513 case 'i':
514 params->stop_us = get_llong_from_str(optarg);
515 break;
516 case 'n':
517 params->output_divisor = 1;
518 break;
519 case 'p':
520 params->timerlat_period_us = get_llong_from_str(optarg);
521 if (params->timerlat_period_us > 1000000)
522 timerlat_top_usage("Period longer than 1 s\n");
523 break;
524 case 'P':
525 retval = parse_prio(optarg, ¶ms->sched_param);
526 if (retval == -1)
527 timerlat_top_usage("Invalid -P priority");
528 params->set_sched = 1;
529 break;
530 case 'q':
531 params->quiet = 1;
532 break;
533 case 's':
534 params->print_stack = get_llong_from_str(optarg);
535 break;
536 case 'T':
537 params->stop_total_us = get_llong_from_str(optarg);
538 break;
539 case 't':
540 if (optarg)
541 /* skip = */
542 params->trace_output = &optarg[1];
543 else
544 params->trace_output = "timerlat_trace.txt";
545
546 break;
547 case 'u':
548 params->user_top = true;
549 break;
550 case '0': /* trigger */
551 if (params->events) {
552 retval = trace_event_add_trigger(params->events, optarg);
553 if (retval) {
554 err_msg("Error adding trigger %s\n", optarg);
555 exit(EXIT_FAILURE);
556 }
557 } else {
558 timerlat_top_usage("--trigger requires a previous -e\n");
559 }
560 break;
561 case '1': /* filter */
562 if (params->events) {
563 retval = trace_event_add_filter(params->events, optarg);
564 if (retval) {
565 err_msg("Error adding filter %s\n", optarg);
566 exit(EXIT_FAILURE);
567 }
568 } else {
569 timerlat_top_usage("--filter requires a previous -e\n");
570 }
571 break;
572 case '2': /* dma-latency */
573 params->dma_latency = get_llong_from_str(optarg);
574 if (params->dma_latency < 0 || params->dma_latency > 10000) {
575 err_msg("--dma-latency needs to be >= 0 and < 10000");
576 exit(EXIT_FAILURE);
577 }
578 break;
579 case '3': /* no-aa */
580 params->no_aa = 1;
581 break;
582 case '4':
583 params->dump_tasks = 1;
584 break;
585 default:
586 timerlat_top_usage("Invalid option");
587 }
588 }
589
590 if (geteuid()) {
591 err_msg("rtla needs root permission\n");
592 exit(EXIT_FAILURE);
593 }
594
595 /*
596 * Auto analysis only happens if stop tracing, thus:
597 */
598 if (!params->stop_us && !params->stop_total_us)
599 params->no_aa = 1;
600
601 if (params->no_aa && params->aa_only)
602 timerlat_top_usage("--no-aa and --aa-only are mutually exclusive!");
603
604 return params;
605 }
606
607 /*
608 * timerlat_top_apply_config - apply the top configs to the initialized tool
609 */
610 static int
timerlat_top_apply_config(struct osnoise_tool * top,struct timerlat_top_params * params)611 timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *params)
612 {
613 int retval;
614 int i;
615
616 if (!params->sleep_time)
617 params->sleep_time = 1;
618
619 if (params->cpus) {
620 retval = osnoise_set_cpus(top->context, params->cpus);
621 if (retval) {
622 err_msg("Failed to apply CPUs config\n");
623 goto out_err;
624 }
625 } else {
626 for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
627 CPU_SET(i, ¶ms->monitored_cpus);
628 }
629
630 if (params->stop_us) {
631 retval = osnoise_set_stop_us(top->context, params->stop_us);
632 if (retval) {
633 err_msg("Failed to set stop us\n");
634 goto out_err;
635 }
636 }
637
638 if (params->stop_total_us) {
639 retval = osnoise_set_stop_total_us(top->context, params->stop_total_us);
640 if (retval) {
641 err_msg("Failed to set stop total us\n");
642 goto out_err;
643 }
644 }
645
646
647 if (params->timerlat_period_us) {
648 retval = osnoise_set_timerlat_period_us(top->context, params->timerlat_period_us);
649 if (retval) {
650 err_msg("Failed to set timerlat period\n");
651 goto out_err;
652 }
653 }
654
655
656 if (params->print_stack) {
657 retval = osnoise_set_print_stack(top->context, params->print_stack);
658 if (retval) {
659 err_msg("Failed to set print stack\n");
660 goto out_err;
661 }
662 }
663
664 if (params->hk_cpus) {
665 retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
666 ¶ms->hk_cpu_set);
667 if (retval == -1) {
668 err_msg("Failed to set rtla to the house keeping CPUs\n");
669 goto out_err;
670 }
671 } else if (params->cpus) {
672 /*
673 * Even if the user do not set a house-keeping CPU, try to
674 * move rtla to a CPU set different to the one where the user
675 * set the workload to run.
676 *
677 * No need to check results as this is an automatic attempt.
678 */
679 auto_house_keeping(¶ms->monitored_cpus);
680 }
681
682 /*
683 * Set workload according to type of thread if the kernel supports it.
684 * On kernels without support, user threads will have already failed
685 * on missing timerlat_fd, and kernel threads do not need it.
686 */
687 retval = osnoise_set_workload(top->context, !params->user_top);
688 if (retval < -1) {
689 err_msg("Failed to set OSNOISE_WORKLOAD option\n");
690 goto out_err;
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;
731 static struct trace_instance *top_inst = NULL;
stop_top(int sig)732 static void stop_top(int sig)
733 {
734 if (stop_tracing) {
735 /*
736 * Stop requested twice in a row; abort event processing and
737 * exit immediately
738 */
739 tracefs_iterate_stop(top_inst->inst);
740 return;
741 }
742 stop_tracing = 1;
743 if (top_inst)
744 trace_instance_stop(top_inst);
745 }
746
747 /*
748 * timerlat_top_set_signals - handles the signal to stop the tool
749 */
750 static void
timerlat_top_set_signals(struct timerlat_top_params * params)751 timerlat_top_set_signals(struct timerlat_top_params *params)
752 {
753 signal(SIGINT, stop_top);
754 if (params->duration) {
755 signal(SIGALRM, stop_top);
756 alarm(params->duration);
757 }
758 }
759
timerlat_top_main(int argc,char * argv[])760 int timerlat_top_main(int argc, char *argv[])
761 {
762 struct timerlat_top_params *params;
763 struct osnoise_tool *record = NULL;
764 struct timerlat_u_params params_u;
765 struct osnoise_tool *top = NULL;
766 struct osnoise_tool *aa = NULL;
767 struct trace_instance *trace;
768 int dma_latency_fd = -1;
769 pthread_t timerlat_u;
770 int return_value = 1;
771 char *max_lat;
772 int retval;
773
774 params = timerlat_top_parse_args(argc, argv);
775 if (!params)
776 exit(1);
777
778 top = timerlat_init_top(params);
779 if (!top) {
780 err_msg("Could not init osnoise top\n");
781 goto out_exit;
782 }
783
784 retval = timerlat_top_apply_config(top, params);
785 if (retval) {
786 err_msg("Could not apply config\n");
787 goto out_free;
788 }
789
790 trace = &top->trace;
791 /*
792 * Save trace instance into global variable so that SIGINT can stop
793 * the timerlat tracer.
794 * Otherwise, rtla could loop indefinitely when overloaded.
795 */
796 top_inst = trace;
797
798
799 retval = enable_timerlat(trace);
800 if (retval) {
801 err_msg("Failed to enable timerlat tracer\n");
802 goto out_free;
803 }
804
805 if (params->set_sched) {
806 retval = set_comm_sched_attr("timerlat/", ¶ms->sched_param);
807 if (retval) {
808 err_msg("Failed to set sched parameters\n");
809 goto out_free;
810 }
811 }
812
813 if (params->cgroup && !params->user_top) {
814 retval = set_comm_cgroup("timerlat/", params->cgroup_name);
815 if (!retval) {
816 err_msg("Failed to move threads to cgroup\n");
817 goto out_free;
818 }
819 }
820
821 if (params->dma_latency >= 0) {
822 dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
823 if (dma_latency_fd < 0) {
824 err_msg("Could not set /dev/cpu_dma_latency.\n");
825 goto out_free;
826 }
827 }
828
829 if (params->trace_output) {
830 record = osnoise_init_trace_tool("timerlat");
831 if (!record) {
832 err_msg("Failed to enable the trace instance\n");
833 goto out_free;
834 }
835
836 if (params->events) {
837 retval = trace_events_enable(&record->trace, params->events);
838 if (retval)
839 goto out_top;
840 }
841 }
842
843 if (!params->no_aa) {
844 if (params->aa_only) {
845 /* as top is not used for display, use it for aa */
846 aa = top;
847 } else {
848 /* otherwise, a new instance is needed */
849 aa = osnoise_init_tool("timerlat_aa");
850 if (!aa)
851 goto out_top;
852 }
853
854 retval = timerlat_aa_init(aa, params->dump_tasks);
855 if (retval) {
856 err_msg("Failed to enable the auto analysis instance\n");
857 goto out_top;
858 }
859
860 /* if it is re-using the main instance, there is no need to start it */
861 if (aa != top) {
862 retval = enable_timerlat(&aa->trace);
863 if (retval) {
864 err_msg("Failed to enable timerlat tracer\n");
865 goto out_top;
866 }
867 }
868 }
869
870 /*
871 * Start the tracers here, after having set all instances.
872 *
873 * Let the trace instance start first for the case of hitting a stop
874 * tracing while enabling other instances. The trace instance is the
875 * one with most valuable information.
876 */
877 if (params->trace_output)
878 trace_instance_start(&record->trace);
879 if (!params->no_aa && aa != top)
880 trace_instance_start(&aa->trace);
881 trace_instance_start(trace);
882
883 top->start_time = time(NULL);
884 timerlat_top_set_signals(params);
885
886 if (params->user_top) {
887 /* rtla asked to stop */
888 params_u.should_run = 1;
889 /* all threads left */
890 params_u.stopped_running = 0;
891
892 params_u.set = ¶ms->monitored_cpus;
893 if (params->set_sched)
894 params_u.sched_param = ¶ms->sched_param;
895 else
896 params_u.sched_param = NULL;
897
898 params_u.cgroup_name = params->cgroup_name;
899
900 retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, ¶ms_u);
901 if (retval)
902 err_msg("Error creating timerlat user-space threads\n");
903 }
904
905 while (!stop_tracing) {
906 sleep(params->sleep_time);
907
908 if (params->aa_only && !trace_is_off(&top->trace, &record->trace))
909 continue;
910
911 retval = tracefs_iterate_raw_events(trace->tep,
912 trace->inst,
913 NULL,
914 0,
915 collect_registered_events,
916 trace);
917 if (retval < 0) {
918 err_msg("Error iterating on events\n");
919 goto out_top;
920 }
921
922 if (!params->quiet)
923 timerlat_print_stats(params, top);
924
925 if (trace_is_off(&top->trace, &record->trace))
926 break;
927
928 /* is there still any user-threads ? */
929 if (params->user_top) {
930 if (params_u.stopped_running) {
931 debug_msg("timerlat user space threads stopped!\n");
932 break;
933 }
934 }
935 }
936
937 if (params->user_top && !params_u.stopped_running) {
938 params_u.should_run = 0;
939 sleep(1);
940 }
941
942 timerlat_print_stats(params, top);
943
944 return_value = 0;
945
946 if (trace_is_off(&top->trace, &record->trace) && !stop_tracing) {
947 printf("rtla timerlat hit stop tracing\n");
948
949 if (!params->no_aa)
950 timerlat_auto_analysis(params->stop_us, params->stop_total_us);
951
952 if (params->trace_output) {
953 printf(" Saving trace to %s\n", params->trace_output);
954 save_trace_to_file(record->trace.inst, params->trace_output);
955 }
956 } else if (params->aa_only) {
957 /*
958 * If the trace did not stop with --aa-only, at least print the
959 * max known latency.
960 */
961 max_lat = tracefs_instance_file_read(trace->inst, "tracing_max_latency", NULL);
962 if (max_lat) {
963 printf(" Max latency was %s\n", max_lat);
964 free(max_lat);
965 }
966 }
967
968 out_top:
969 timerlat_aa_destroy();
970 if (dma_latency_fd >= 0)
971 close(dma_latency_fd);
972 trace_events_destroy(&record->trace, params->events);
973 params->events = NULL;
974 out_free:
975 timerlat_free_top(top->data);
976 if (aa && aa != top)
977 osnoise_destroy_tool(aa);
978 osnoise_destroy_tool(record);
979 osnoise_destroy_tool(top);
980 free(params);
981 out_exit:
982 exit(return_value);
983 }
984