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 "timerlat.h"
19 #include "timerlat_aa.h"
20 #include "timerlat_u.h"
21 #include "timerlat_bpf.h"
22
23 struct timerlat_top_cpu {
24 unsigned long long irq_count;
25 unsigned long long thread_count;
26 unsigned long long user_count;
27
28 unsigned long long cur_irq;
29 unsigned long long min_irq;
30 unsigned long long sum_irq;
31 unsigned long long max_irq;
32
33 unsigned long long cur_thread;
34 unsigned long long min_thread;
35 unsigned long long sum_thread;
36 unsigned long long max_thread;
37
38 unsigned long long cur_user;
39 unsigned long long min_user;
40 unsigned long long sum_user;
41 unsigned long long max_user;
42 };
43
44 struct timerlat_top_data {
45 struct timerlat_top_cpu *cpu_data;
46 int nr_cpus;
47 };
48
49 /*
50 * timerlat_free_top - free runtime data
51 */
52 static void
timerlat_free_top(struct timerlat_top_data * data)53 timerlat_free_top(struct timerlat_top_data *data)
54 {
55 free(data->cpu_data);
56 free(data);
57 }
58
59 /*
60 * timerlat_alloc_histogram - alloc runtime data
61 */
timerlat_alloc_top(int nr_cpus)62 static struct timerlat_top_data *timerlat_alloc_top(int nr_cpus)
63 {
64 struct timerlat_top_data *data;
65 int cpu;
66
67 data = calloc(1, sizeof(*data));
68 if (!data)
69 return NULL;
70
71 data->nr_cpus = nr_cpus;
72
73 /* one set of histograms per CPU */
74 data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus);
75 if (!data->cpu_data)
76 goto cleanup;
77
78 /* set the min to max */
79 for (cpu = 0; cpu < nr_cpus; cpu++) {
80 data->cpu_data[cpu].min_irq = ~0;
81 data->cpu_data[cpu].min_thread = ~0;
82 data->cpu_data[cpu].min_user = ~0;
83 }
84
85 return data;
86
87 cleanup:
88 timerlat_free_top(data);
89 return NULL;
90 }
91
92 static void
timerlat_top_reset_sum(struct timerlat_top_cpu * summary)93 timerlat_top_reset_sum(struct timerlat_top_cpu *summary)
94 {
95 memset(summary, 0, sizeof(*summary));
96 summary->min_irq = ~0;
97 summary->min_thread = ~0;
98 summary->min_user = ~0;
99 }
100
101 static void
timerlat_top_update_sum(struct osnoise_tool * tool,int cpu,struct timerlat_top_cpu * sum)102 timerlat_top_update_sum(struct osnoise_tool *tool, int cpu, struct timerlat_top_cpu *sum)
103 {
104 struct timerlat_top_data *data = tool->data;
105 struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
106
107 sum->irq_count += cpu_data->irq_count;
108 update_min(&sum->min_irq, &cpu_data->min_irq);
109 update_sum(&sum->sum_irq, &cpu_data->sum_irq);
110 update_max(&sum->max_irq, &cpu_data->max_irq);
111
112 sum->thread_count += cpu_data->thread_count;
113 update_min(&sum->min_thread, &cpu_data->min_thread);
114 update_sum(&sum->sum_thread, &cpu_data->sum_thread);
115 update_max(&sum->max_thread, &cpu_data->max_thread);
116
117 sum->user_count += cpu_data->user_count;
118 update_min(&sum->min_user, &cpu_data->min_user);
119 update_sum(&sum->sum_user, &cpu_data->sum_user);
120 update_max(&sum->max_user, &cpu_data->max_user);
121 }
122
123 /*
124 * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
125 */
126 static void
timerlat_top_update(struct osnoise_tool * tool,int cpu,unsigned long long thread,unsigned long long latency)127 timerlat_top_update(struct osnoise_tool *tool, int cpu,
128 unsigned long long thread,
129 unsigned long long latency)
130 {
131 struct timerlat_params *params = tool->params;
132 struct timerlat_top_data *data = tool->data;
133 struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
134
135 if (params->output_divisor)
136 latency = latency / params->output_divisor;
137
138 if (!thread) {
139 cpu_data->irq_count++;
140 cpu_data->cur_irq = latency;
141 update_min(&cpu_data->min_irq, &latency);
142 update_sum(&cpu_data->sum_irq, &latency);
143 update_max(&cpu_data->max_irq, &latency);
144 } else if (thread == 1) {
145 cpu_data->thread_count++;
146 cpu_data->cur_thread = latency;
147 update_min(&cpu_data->min_thread, &latency);
148 update_sum(&cpu_data->sum_thread, &latency);
149 update_max(&cpu_data->max_thread, &latency);
150 } else {
151 cpu_data->user_count++;
152 cpu_data->cur_user = latency;
153 update_min(&cpu_data->min_user, &latency);
154 update_sum(&cpu_data->sum_user, &latency);
155 update_max(&cpu_data->max_user, &latency);
156 }
157 }
158
159 /*
160 * timerlat_top_handler - this is the handler for timerlat tracer events
161 */
162 static int
timerlat_top_handler(struct trace_seq * s,struct tep_record * record,struct tep_event * event,void * context)163 timerlat_top_handler(struct trace_seq *s, struct tep_record *record,
164 struct tep_event *event, void *context)
165 {
166 struct trace_instance *trace = context;
167 struct timerlat_params *params;
168 unsigned long long latency, thread;
169 struct osnoise_tool *top;
170 int cpu = record->cpu;
171
172 top = container_of(trace, struct osnoise_tool, trace);
173 params = top->params;
174
175 if (!params->aa_only) {
176 tep_get_field_val(s, event, "context", record, &thread, 1);
177 tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
178
179 timerlat_top_update(top, cpu, thread, latency);
180 }
181
182 return 0;
183 }
184
185 /*
186 * timerlat_top_bpf_pull_data - copy data from BPF maps into userspace
187 */
timerlat_top_bpf_pull_data(struct osnoise_tool * tool)188 static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
189 {
190 struct timerlat_top_data *data = tool->data;
191 int i, err;
192 long long value_irq[data->nr_cpus],
193 value_thread[data->nr_cpus],
194 value_user[data->nr_cpus];
195
196 /* Pull summary */
197 err = timerlat_bpf_get_summary_value(SUMMARY_CURRENT,
198 value_irq, value_thread, value_user,
199 data->nr_cpus);
200 if (err)
201 return err;
202 for (i = 0; i < data->nr_cpus; i++) {
203 data->cpu_data[i].cur_irq = value_irq[i];
204 data->cpu_data[i].cur_thread = value_thread[i];
205 data->cpu_data[i].cur_user = value_user[i];
206 }
207
208 err = timerlat_bpf_get_summary_value(SUMMARY_COUNT,
209 value_irq, value_thread, value_user,
210 data->nr_cpus);
211 if (err)
212 return err;
213 for (i = 0; i < data->nr_cpus; i++) {
214 data->cpu_data[i].irq_count = value_irq[i];
215 data->cpu_data[i].thread_count = value_thread[i];
216 data->cpu_data[i].user_count = value_user[i];
217 }
218
219 err = timerlat_bpf_get_summary_value(SUMMARY_MIN,
220 value_irq, value_thread, value_user,
221 data->nr_cpus);
222 if (err)
223 return err;
224 for (i = 0; i < data->nr_cpus; i++) {
225 data->cpu_data[i].min_irq = value_irq[i];
226 data->cpu_data[i].min_thread = value_thread[i];
227 data->cpu_data[i].min_user = value_user[i];
228 }
229
230 err = timerlat_bpf_get_summary_value(SUMMARY_MAX,
231 value_irq, value_thread, value_user,
232 data->nr_cpus);
233 if (err)
234 return err;
235 for (i = 0; i < data->nr_cpus; i++) {
236 data->cpu_data[i].max_irq = value_irq[i];
237 data->cpu_data[i].max_thread = value_thread[i];
238 data->cpu_data[i].max_user = value_user[i];
239 }
240
241 err = timerlat_bpf_get_summary_value(SUMMARY_SUM,
242 value_irq, value_thread, value_user,
243 data->nr_cpus);
244 if (err)
245 return err;
246 for (i = 0; i < data->nr_cpus; i++) {
247 data->cpu_data[i].sum_irq = value_irq[i];
248 data->cpu_data[i].sum_thread = value_thread[i];
249 data->cpu_data[i].sum_user = value_user[i];
250 }
251
252 return 0;
253 }
254
255 /*
256 * timerlat_top_header - print the header of the tool output
257 */
timerlat_top_header(struct timerlat_params * params,struct osnoise_tool * top)258 static void timerlat_top_header(struct timerlat_params *params, struct osnoise_tool *top)
259 {
260 struct trace_seq *s = top->trace.seq;
261 char duration[26];
262
263 get_duration(top->start_time, duration, sizeof(duration));
264
265 if (params->pretty_output)
266 trace_seq_printf(s, "\033[2;37;40m");
267
268 trace_seq_printf(s, " Timer Latency ");
269 if (params->user_data)
270 trace_seq_printf(s, " ");
271
272 if (params->pretty_output)
273 trace_seq_printf(s, "\033[0;0;0m");
274 trace_seq_printf(s, "\n");
275
276 trace_seq_printf(s, "%-6s | IRQ Timer Latency (%s) | Thread Timer Latency (%s)", duration,
277 params->output_divisor == 1 ? "ns" : "us",
278 params->output_divisor == 1 ? "ns" : "us");
279
280 if (params->user_data) {
281 trace_seq_printf(s, " | Ret user Timer Latency (%s)",
282 params->output_divisor == 1 ? "ns" : "us");
283 }
284
285 trace_seq_printf(s, "\n");
286 if (params->pretty_output)
287 trace_seq_printf(s, "\033[2;30;47m");
288
289 trace_seq_printf(s, "CPU COUNT | cur min avg max | cur min avg max");
290 if (params->user_data)
291 trace_seq_printf(s, " | cur min avg max");
292
293 if (params->pretty_output)
294 trace_seq_printf(s, "\033[0;0;0m");
295 trace_seq_printf(s, "\n");
296 }
297
298 static const char *no_value = " -";
299
300 /*
301 * timerlat_top_print - prints the output of a given CPU
302 */
timerlat_top_print(struct osnoise_tool * top,int cpu)303 static void timerlat_top_print(struct osnoise_tool *top, int cpu)
304 {
305
306 struct timerlat_params *params = top->params;
307 struct timerlat_top_data *data = top->data;
308 struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
309 struct trace_seq *s = top->trace.seq;
310
311 /*
312 * Skip if no data is available: is this cpu offline?
313 */
314 if (!cpu_data->irq_count && !cpu_data->thread_count)
315 return;
316
317 /*
318 * Unless trace is being lost, IRQ counter is always the max.
319 */
320 trace_seq_printf(s, "%3d #%-9llu |", cpu, cpu_data->irq_count);
321
322 if (!cpu_data->irq_count) {
323 trace_seq_printf(s, "%s %s %s %s |", no_value, no_value, no_value, no_value);
324 } else {
325 trace_seq_printf(s, "%9llu ", cpu_data->cur_irq);
326 trace_seq_printf(s, "%9llu ", cpu_data->min_irq);
327 trace_seq_printf(s, "%9llu ", cpu_data->sum_irq / cpu_data->irq_count);
328 trace_seq_printf(s, "%9llu |", cpu_data->max_irq);
329 }
330
331 if (!cpu_data->thread_count) {
332 trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
333 } else {
334 trace_seq_printf(s, "%9llu ", cpu_data->cur_thread);
335 trace_seq_printf(s, "%9llu ", cpu_data->min_thread);
336 trace_seq_printf(s, "%9llu ",
337 cpu_data->sum_thread / cpu_data->thread_count);
338 trace_seq_printf(s, "%9llu", cpu_data->max_thread);
339 }
340
341 if (!params->user_data) {
342 trace_seq_printf(s, "\n");
343 return;
344 }
345
346 trace_seq_printf(s, " |");
347
348 if (!cpu_data->user_count) {
349 trace_seq_printf(s, "%s %s %s %s\n", no_value, no_value, no_value, no_value);
350 } else {
351 trace_seq_printf(s, "%9llu ", cpu_data->cur_user);
352 trace_seq_printf(s, "%9llu ", cpu_data->min_user);
353 trace_seq_printf(s, "%9llu ",
354 cpu_data->sum_user / cpu_data->user_count);
355 trace_seq_printf(s, "%9llu\n", cpu_data->max_user);
356 }
357 }
358
359 /*
360 * timerlat_top_print_sum - prints the summary output
361 */
362 static void
timerlat_top_print_sum(struct osnoise_tool * top,struct timerlat_top_cpu * summary)363 timerlat_top_print_sum(struct osnoise_tool *top, struct timerlat_top_cpu *summary)
364 {
365 const char *split = "----------------------------------------";
366 struct timerlat_params *params = top->params;
367 unsigned long long count = summary->irq_count;
368 struct trace_seq *s = top->trace.seq;
369 int e = 0;
370
371 /*
372 * Skip if no data is available: is this cpu offline?
373 */
374 if (!summary->irq_count && !summary->thread_count)
375 return;
376
377 while (count > 999999) {
378 e++;
379 count /= 10;
380 }
381
382 trace_seq_printf(s, "%.*s|%.*s|%.*s", 15, split, 40, split, 39, split);
383 if (params->user_data)
384 trace_seq_printf(s, "-|%.*s", 39, split);
385 trace_seq_printf(s, "\n");
386
387 trace_seq_printf(s, "ALL #%-6llu e%d |", count, e);
388
389 if (!summary->irq_count) {
390 trace_seq_printf(s, " %s %s %s |", no_value, no_value, no_value);
391 } else {
392 trace_seq_printf(s, " ");
393 trace_seq_printf(s, "%9llu ", summary->min_irq);
394 trace_seq_printf(s, "%9llu ", summary->sum_irq / summary->irq_count);
395 trace_seq_printf(s, "%9llu |", summary->max_irq);
396 }
397
398 if (!summary->thread_count) {
399 trace_seq_printf(s, "%s %s %s %s", no_value, no_value, no_value, no_value);
400 } else {
401 trace_seq_printf(s, " ");
402 trace_seq_printf(s, "%9llu ", summary->min_thread);
403 trace_seq_printf(s, "%9llu ",
404 summary->sum_thread / summary->thread_count);
405 trace_seq_printf(s, "%9llu", summary->max_thread);
406 }
407
408 if (!params->user_data) {
409 trace_seq_printf(s, "\n");
410 return;
411 }
412
413 trace_seq_printf(s, " |");
414
415 if (!summary->user_count) {
416 trace_seq_printf(s, " %s %s %s |", no_value, no_value, no_value);
417 } else {
418 trace_seq_printf(s, " ");
419 trace_seq_printf(s, "%9llu ", summary->min_user);
420 trace_seq_printf(s, "%9llu ",
421 summary->sum_user / summary->user_count);
422 trace_seq_printf(s, "%9llu\n", summary->max_user);
423 }
424 }
425
426 /*
427 * clear_terminal - clears the output terminal
428 */
clear_terminal(struct trace_seq * seq)429 static void clear_terminal(struct trace_seq *seq)
430 {
431 if (!config_debug)
432 trace_seq_printf(seq, "\033c");
433 }
434
435 /*
436 * timerlat_print_stats - print data for all cpus
437 */
438 static void
timerlat_print_stats(struct timerlat_params * params,struct osnoise_tool * top)439 timerlat_print_stats(struct timerlat_params *params, struct osnoise_tool *top)
440 {
441 struct trace_instance *trace = &top->trace;
442 struct timerlat_top_cpu summary;
443 static int nr_cpus = -1;
444 int i;
445
446 if (params->aa_only)
447 return;
448
449 if (nr_cpus == -1)
450 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
451
452 if (!params->quiet)
453 clear_terminal(trace->seq);
454
455 timerlat_top_reset_sum(&summary);
456
457 timerlat_top_header(params, top);
458
459 for (i = 0; i < nr_cpus; i++) {
460 if (params->cpus && !CPU_ISSET(i, ¶ms->monitored_cpus))
461 continue;
462 timerlat_top_print(top, i);
463 timerlat_top_update_sum(top, i, &summary);
464 }
465
466 timerlat_top_print_sum(top, &summary);
467
468 trace_seq_do_printf(trace->seq);
469 trace_seq_reset(trace->seq);
470 osnoise_report_missed_events(top);
471 }
472
473 /*
474 * timerlat_top_usage - prints timerlat top usage message
475 */
timerlat_top_usage(char * usage)476 static void timerlat_top_usage(char *usage)
477 {
478 int i;
479
480 static const char *const msg[] = {
481 "",
482 " usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
483 " [[-t[file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] [-H cpu-list]\\",
484 " [-P priority] [--dma-latency us] [--aa-only us] [-C[=cgroup_name]] [-u|-k] [--warm-up s] [--deepest-idle-state n]",
485 "",
486 " -h/--help: print this menu",
487 " -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
488 " --aa-only us: stop if <us> latency is hit, only printing the auto analysis (reduces CPU usage)",
489 " -p/--period us: timerlat period in us",
490 " -i/--irq us: stop trace if the irq latency is higher than the argument in us",
491 " -T/--thread us: stop trace if the thread latency is higher than the argument in us",
492 " -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
493 " -c/--cpus cpus: run the tracer only on the given cpus",
494 " -H/--house-keeping cpus: run rtla control threads only on the given cpus",
495 " -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
496 " -d/--duration time[s|m|h|d]: duration of the session",
497 " -D/--debug: print debug info",
498 " --dump-tasks: prints the task running on all CPUs if stop conditions are met (depends on !--no-aa)",
499 " -t/--trace[file]: save the stopped trace to [file|timerlat_trace.txt]",
500 " -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
501 " --filter <command>: enable a trace event filter to the previous -e event",
502 " --trigger <command>: enable a trace event trigger to the previous -e event",
503 " -n/--nano: display data in nanoseconds",
504 " --no-aa: disable auto-analysis, reducing rtla timerlat cpu usage",
505 " -q/--quiet print only a summary at the end",
506 " --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
507 " -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
508 " o:prio - use SCHED_OTHER with prio",
509 " r:prio - use SCHED_RR with prio",
510 " f:prio - use SCHED_FIFO with prio",
511 " d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
512 " in nanoseconds",
513 " -u/--user-threads: use rtla user-space threads instead of kernel-space timerlat threads",
514 " -k/--kernel-threads: use timerlat kernel-space threads instead of rtla user-space threads",
515 " -U/--user-load: enable timerlat for user-defined user-space workload",
516 " --warm-up s: let the workload run for s seconds before collecting data",
517 " --trace-buffer-size kB: set the per-cpu trace buffer size in kB",
518 " --deepest-idle-state n: only go down to idle state n on cpus used by timerlat to reduce exit from idle latency",
519 " --on-threshold <action>: define action to be executed at latency threshold, multiple are allowed",
520 " --on-end: define action to be executed at measurement end, multiple are allowed",
521 NULL,
522 };
523
524 if (usage)
525 fprintf(stderr, "%s\n", usage);
526
527 fprintf(stderr, "rtla timerlat top: a per-cpu summary of the timer latency (version %s)\n",
528 VERSION);
529
530 for (i = 0; msg[i]; i++)
531 fprintf(stderr, "%s\n", msg[i]);
532
533 if (usage)
534 exit(EXIT_FAILURE);
535
536 exit(EXIT_SUCCESS);
537 }
538
539 /*
540 * timerlat_top_parse_args - allocs, parse and fill the cmd line parameters
541 */
542 static struct timerlat_params
timerlat_top_parse_args(int argc,char ** argv)543 *timerlat_top_parse_args(int argc, char **argv)
544 {
545 struct timerlat_params *params;
546 struct trace_events *tevent;
547 long long auto_thresh;
548 int retval;
549 int c;
550 char *trace_output = NULL;
551
552 params = calloc(1, sizeof(*params));
553 if (!params)
554 exit(1);
555
556 actions_init(¶ms->threshold_actions);
557 actions_init(¶ms->end_actions);
558
559 /* disabled by default */
560 params->dma_latency = -1;
561
562 /* disabled by default */
563 params->deepest_idle_state = -2;
564
565 /* display data in microseconds */
566 params->output_divisor = 1000;
567
568 /* default to BPF mode */
569 params->mode = TRACING_MODE_BPF;
570
571 while (1) {
572 static struct option long_options[] = {
573 {"auto", required_argument, 0, 'a'},
574 {"cpus", required_argument, 0, 'c'},
575 {"cgroup", optional_argument, 0, 'C'},
576 {"debug", no_argument, 0, 'D'},
577 {"duration", required_argument, 0, 'd'},
578 {"event", required_argument, 0, 'e'},
579 {"help", no_argument, 0, 'h'},
580 {"house-keeping", required_argument, 0, 'H'},
581 {"irq", required_argument, 0, 'i'},
582 {"nano", no_argument, 0, 'n'},
583 {"period", required_argument, 0, 'p'},
584 {"priority", required_argument, 0, 'P'},
585 {"quiet", no_argument, 0, 'q'},
586 {"stack", required_argument, 0, 's'},
587 {"thread", required_argument, 0, 'T'},
588 {"trace", optional_argument, 0, 't'},
589 {"user-threads", no_argument, 0, 'u'},
590 {"kernel-threads", no_argument, 0, 'k'},
591 {"user-load", no_argument, 0, 'U'},
592 {"trigger", required_argument, 0, '0'},
593 {"filter", required_argument, 0, '1'},
594 {"dma-latency", required_argument, 0, '2'},
595 {"no-aa", no_argument, 0, '3'},
596 {"dump-tasks", no_argument, 0, '4'},
597 {"aa-only", required_argument, 0, '5'},
598 {"warm-up", required_argument, 0, '6'},
599 {"trace-buffer-size", required_argument, 0, '7'},
600 {"deepest-idle-state", required_argument, 0, '8'},
601 {"on-threshold", required_argument, 0, '9'},
602 {"on-end", required_argument, 0, '\1'},
603 {0, 0, 0, 0}
604 };
605
606 /* getopt_long stores the option index here. */
607 int option_index = 0;
608
609 c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:knp:P:qs:t::T:uU0:1:2:345:6:7:",
610 long_options, &option_index);
611
612 /* detect the end of the options. */
613 if (c == -1)
614 break;
615
616 switch (c) {
617 case 'a':
618 auto_thresh = get_llong_from_str(optarg);
619
620 /* set thread stop to auto_thresh */
621 params->stop_total_us = auto_thresh;
622 params->stop_us = auto_thresh;
623
624 /* get stack trace */
625 params->print_stack = auto_thresh;
626
627 /* set trace */
628 trace_output = "timerlat_trace.txt";
629
630 break;
631 case '5':
632 /* it is here because it is similar to -a */
633 auto_thresh = get_llong_from_str(optarg);
634
635 /* set thread stop to auto_thresh */
636 params->stop_total_us = auto_thresh;
637 params->stop_us = auto_thresh;
638
639 /* get stack trace */
640 params->print_stack = auto_thresh;
641
642 /* set aa_only to avoid parsing the trace */
643 params->aa_only = 1;
644 break;
645 case 'c':
646 retval = parse_cpu_set(optarg, ¶ms->monitored_cpus);
647 if (retval)
648 timerlat_top_usage("\nInvalid -c cpu list\n");
649 params->cpus = optarg;
650 break;
651 case 'C':
652 params->cgroup = 1;
653 if (!optarg) {
654 /* will inherit this cgroup */
655 params->cgroup_name = NULL;
656 } else if (*optarg == '=') {
657 /* skip the = */
658 params->cgroup_name = ++optarg;
659 }
660 break;
661 case 'D':
662 config_debug = 1;
663 break;
664 case 'd':
665 params->duration = parse_seconds_duration(optarg);
666 if (!params->duration)
667 timerlat_top_usage("Invalid -d duration\n");
668 break;
669 case 'e':
670 tevent = trace_event_alloc(optarg);
671 if (!tevent) {
672 err_msg("Error alloc trace event");
673 exit(EXIT_FAILURE);
674 }
675
676 if (params->events)
677 tevent->next = params->events;
678 params->events = tevent;
679 break;
680 case 'h':
681 case '?':
682 timerlat_top_usage(NULL);
683 break;
684 case 'H':
685 params->hk_cpus = 1;
686 retval = parse_cpu_set(optarg, ¶ms->hk_cpu_set);
687 if (retval) {
688 err_msg("Error parsing house keeping CPUs\n");
689 exit(EXIT_FAILURE);
690 }
691 break;
692 case 'i':
693 params->stop_us = get_llong_from_str(optarg);
694 break;
695 case 'k':
696 params->kernel_workload = true;
697 break;
698 case 'n':
699 params->output_divisor = 1;
700 break;
701 case 'p':
702 params->timerlat_period_us = get_llong_from_str(optarg);
703 if (params->timerlat_period_us > 1000000)
704 timerlat_top_usage("Period longer than 1 s\n");
705 break;
706 case 'P':
707 retval = parse_prio(optarg, ¶ms->sched_param);
708 if (retval == -1)
709 timerlat_top_usage("Invalid -P priority");
710 params->set_sched = 1;
711 break;
712 case 'q':
713 params->quiet = 1;
714 break;
715 case 's':
716 params->print_stack = get_llong_from_str(optarg);
717 break;
718 case 'T':
719 params->stop_total_us = get_llong_from_str(optarg);
720 break;
721 case 't':
722 if (optarg) {
723 if (optarg[0] == '=')
724 trace_output = &optarg[1];
725 else
726 trace_output = &optarg[0];
727 } else if (optind < argc && argv[optind][0] != '-')
728 trace_output = argv[optind];
729 else
730 trace_output = "timerlat_trace.txt";
731 break;
732 case 'u':
733 params->user_workload = true;
734 /* fallback: -u implies -U */
735 case 'U':
736 params->user_data = true;
737 break;
738 case '0': /* trigger */
739 if (params->events) {
740 retval = trace_event_add_trigger(params->events, optarg);
741 if (retval) {
742 err_msg("Error adding trigger %s\n", optarg);
743 exit(EXIT_FAILURE);
744 }
745 } else {
746 timerlat_top_usage("--trigger requires a previous -e\n");
747 }
748 break;
749 case '1': /* filter */
750 if (params->events) {
751 retval = trace_event_add_filter(params->events, optarg);
752 if (retval) {
753 err_msg("Error adding filter %s\n", optarg);
754 exit(EXIT_FAILURE);
755 }
756 } else {
757 timerlat_top_usage("--filter requires a previous -e\n");
758 }
759 break;
760 case '2': /* dma-latency */
761 params->dma_latency = get_llong_from_str(optarg);
762 if (params->dma_latency < 0 || params->dma_latency > 10000) {
763 err_msg("--dma-latency needs to be >= 0 and < 10000");
764 exit(EXIT_FAILURE);
765 }
766 break;
767 case '3': /* no-aa */
768 params->no_aa = 1;
769 break;
770 case '4':
771 params->dump_tasks = 1;
772 break;
773 case '6':
774 params->warmup = get_llong_from_str(optarg);
775 break;
776 case '7':
777 params->buffer_size = get_llong_from_str(optarg);
778 break;
779 case '8':
780 params->deepest_idle_state = get_llong_from_str(optarg);
781 break;
782 case '9':
783 retval = actions_parse(¶ms->threshold_actions, optarg);
784 if (retval) {
785 err_msg("Invalid action %s\n", optarg);
786 exit(EXIT_FAILURE);
787 }
788 break;
789 case '\1':
790 retval = actions_parse(¶ms->end_actions, optarg);
791 if (retval) {
792 err_msg("Invalid action %s\n", optarg);
793 exit(EXIT_FAILURE);
794 }
795 break;
796 default:
797 timerlat_top_usage("Invalid option");
798 }
799 }
800
801 if (trace_output)
802 actions_add_trace_output(¶ms->threshold_actions, trace_output);
803
804 if (geteuid()) {
805 err_msg("rtla needs root permission\n");
806 exit(EXIT_FAILURE);
807 }
808
809 /*
810 * Auto analysis only happens if stop tracing, thus:
811 */
812 if (!params->stop_us && !params->stop_total_us)
813 params->no_aa = 1;
814
815 if (params->no_aa && params->aa_only)
816 timerlat_top_usage("--no-aa and --aa-only are mutually exclusive!");
817
818 if (params->kernel_workload && params->user_workload)
819 timerlat_top_usage("--kernel-threads and --user-threads are mutually exclusive!");
820
821 /*
822 * If auto-analysis or trace output is enabled, switch from BPF mode to
823 * mixed mode
824 */
825 if (params->mode == TRACING_MODE_BPF &&
826 (params->threshold_actions.present[ACTION_TRACE_OUTPUT] ||
827 params->end_actions.present[ACTION_TRACE_OUTPUT] || !params->no_aa))
828 params->mode = TRACING_MODE_MIXED;
829
830 return params;
831 }
832
833 /*
834 * timerlat_top_apply_config - apply the top configs to the initialized tool
835 */
836 static int
timerlat_top_apply_config(struct osnoise_tool * top,struct timerlat_params * params)837 timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_params *params)
838 {
839 int retval;
840
841 retval = timerlat_apply_config(top, params);
842 if (retval)
843 goto out_err;
844
845 if (isatty(STDOUT_FILENO) && !params->quiet)
846 params->pretty_output = 1;
847
848 return 0;
849
850 out_err:
851 return -1;
852 }
853
854 /*
855 * timerlat_init_top - initialize a timerlat top tool with parameters
856 */
857 static struct osnoise_tool
timerlat_init_top(struct timerlat_params * params)858 *timerlat_init_top(struct timerlat_params *params)
859 {
860 struct osnoise_tool *top;
861 int nr_cpus;
862
863 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
864
865 top = osnoise_init_tool("timerlat_top");
866 if (!top)
867 return NULL;
868
869 top->data = timerlat_alloc_top(nr_cpus);
870 if (!top->data)
871 goto out_err;
872
873 top->params = params;
874
875 tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat",
876 timerlat_top_handler, top);
877
878 return top;
879
880 out_err:
881 osnoise_destroy_tool(top);
882 return NULL;
883 }
884
885 static int stop_tracing;
886 static struct trace_instance *top_inst = NULL;
stop_top(int sig)887 static void stop_top(int sig)
888 {
889 if (stop_tracing) {
890 /*
891 * Stop requested twice in a row; abort event processing and
892 * exit immediately
893 */
894 tracefs_iterate_stop(top_inst->inst);
895 return;
896 }
897 stop_tracing = 1;
898 if (top_inst)
899 trace_instance_stop(top_inst);
900 }
901
902 /*
903 * timerlat_top_set_signals - handles the signal to stop the tool
904 */
905 static void
timerlat_top_set_signals(struct timerlat_params * params)906 timerlat_top_set_signals(struct timerlat_params *params)
907 {
908 signal(SIGINT, stop_top);
909 if (params->duration) {
910 signal(SIGALRM, stop_top);
911 alarm(params->duration);
912 }
913 }
914
915 /*
916 * timerlat_top_main_loop - main loop to process events
917 */
918 static int
timerlat_top_main_loop(struct osnoise_tool * top,struct osnoise_tool * record,struct osnoise_tool * aa,struct timerlat_params * params,struct timerlat_u_params * params_u)919 timerlat_top_main_loop(struct osnoise_tool *top,
920 struct osnoise_tool *record,
921 struct osnoise_tool *aa,
922 struct timerlat_params *params,
923 struct timerlat_u_params *params_u)
924 {
925 struct trace_instance *trace = &top->trace;
926 int retval;
927
928 while (!stop_tracing) {
929 sleep(params->sleep_time);
930
931 if (params->aa_only && !osnoise_trace_is_off(top, record))
932 continue;
933
934 retval = tracefs_iterate_raw_events(trace->tep,
935 trace->inst,
936 NULL,
937 0,
938 collect_registered_events,
939 trace);
940 if (retval < 0) {
941 err_msg("Error iterating on events\n");
942 return retval;
943 }
944
945 if (!params->quiet)
946 timerlat_print_stats(params, top);
947
948 if (osnoise_trace_is_off(top, record)) {
949 actions_perform(¶ms->threshold_actions);
950
951 if (!params->threshold_actions.continue_flag)
952 /* continue flag not set, break */
953 break;
954
955 /* continue action reached, re-enable tracing */
956 if (record)
957 trace_instance_start(&record->trace);
958 if (!params->no_aa)
959 trace_instance_start(&aa->trace);
960 trace_instance_start(trace);
961 }
962
963 /* is there still any user-threads ? */
964 if (params->user_workload) {
965 if (params_u->stopped_running) {
966 debug_msg("timerlat user space threads stopped!\n");
967 break;
968 }
969 }
970 }
971
972 return 0;
973 }
974
975 /*
976 * timerlat_top_bpf_main_loop - main loop to process events (BPF variant)
977 */
978 static int
timerlat_top_bpf_main_loop(struct osnoise_tool * top,struct osnoise_tool * record,struct osnoise_tool * aa,struct timerlat_params * params,struct timerlat_u_params * params_u)979 timerlat_top_bpf_main_loop(struct osnoise_tool *top,
980 struct osnoise_tool *record,
981 struct osnoise_tool *aa,
982 struct timerlat_params *params,
983 struct timerlat_u_params *params_u)
984 {
985 int retval, wait_retval;
986
987 if (params->aa_only) {
988 /* Auto-analysis only, just wait for stop tracing */
989 timerlat_bpf_wait(-1);
990 return 0;
991 }
992
993 /* Pull and display data in a loop */
994 while (!stop_tracing) {
995 wait_retval = timerlat_bpf_wait(params->quiet ? -1 : params->sleep_time);
996
997 retval = timerlat_top_bpf_pull_data(top);
998 if (retval) {
999 err_msg("Error pulling BPF data\n");
1000 return retval;
1001 }
1002
1003 if (!params->quiet)
1004 timerlat_print_stats(params, top);
1005
1006 if (wait_retval == 1) {
1007 /* Stopping requested by tracer */
1008 actions_perform(¶ms->threshold_actions);
1009
1010 if (!params->threshold_actions.continue_flag)
1011 /* continue flag not set, break */
1012 break;
1013
1014 /* continue action reached, re-enable tracing */
1015 if (record)
1016 trace_instance_start(&record->trace);
1017 if (!params->no_aa)
1018 trace_instance_start(&aa->trace);
1019 timerlat_bpf_restart_tracing();
1020 }
1021
1022 /* is there still any user-threads ? */
1023 if (params->user_workload) {
1024 if (params_u->stopped_running) {
1025 debug_msg("timerlat user space threads stopped!\n");
1026 break;
1027 }
1028 }
1029 }
1030
1031 return 0;
1032 }
1033
timerlat_top_main(int argc,char * argv[])1034 int timerlat_top_main(int argc, char *argv[])
1035 {
1036 struct timerlat_params *params;
1037 struct osnoise_tool *record = NULL;
1038 struct timerlat_u_params params_u;
1039 enum result return_value = ERROR;
1040 struct osnoise_tool *top = NULL;
1041 struct osnoise_tool *aa = NULL;
1042 struct trace_instance *trace;
1043 int dma_latency_fd = -1;
1044 pthread_t timerlat_u;
1045 char *max_lat;
1046 int retval;
1047 int nr_cpus, i;
1048
1049 params = timerlat_top_parse_args(argc, argv);
1050 if (!params)
1051 exit(1);
1052
1053 top = timerlat_init_top(params);
1054 if (!top) {
1055 err_msg("Could not init osnoise top\n");
1056 goto out_exit;
1057 }
1058
1059 trace = &top->trace;
1060 /*
1061 * Save trace instance into global variable so that SIGINT can stop
1062 * the timerlat tracer.
1063 * Otherwise, rtla could loop indefinitely when overloaded.
1064 */
1065 top_inst = trace;
1066
1067 /*
1068 * Try to enable BPF, unless disabled explicitly.
1069 * If BPF enablement fails, fall back to tracefs mode.
1070 */
1071 if (getenv("RTLA_NO_BPF") && strncmp(getenv("RTLA_NO_BPF"), "1", 2) == 0) {
1072 debug_msg("RTLA_NO_BPF set, disabling BPF\n");
1073 params->mode = TRACING_MODE_TRACEFS;
1074 } else if (!tep_find_event_by_name(trace->tep, "osnoise", "timerlat_sample")) {
1075 debug_msg("osnoise:timerlat_sample missing, disabling BPF\n");
1076 params->mode = TRACING_MODE_TRACEFS;
1077 } else {
1078 retval = timerlat_bpf_init(params);
1079 if (retval) {
1080 debug_msg("Could not enable BPF\n");
1081 params->mode = TRACING_MODE_TRACEFS;
1082 }
1083 }
1084
1085 retval = timerlat_top_apply_config(top, params);
1086 if (retval) {
1087 err_msg("Could not apply config\n");
1088 goto out_free;
1089 }
1090
1091 retval = enable_timerlat(trace);
1092 if (retval) {
1093 err_msg("Failed to enable timerlat tracer\n");
1094 goto out_free;
1095 }
1096
1097 if (params->set_sched) {
1098 retval = set_comm_sched_attr("timerlat/", ¶ms->sched_param);
1099 if (retval) {
1100 err_msg("Failed to set sched parameters\n");
1101 goto out_free;
1102 }
1103 }
1104
1105 if (params->cgroup && !params->user_data) {
1106 retval = set_comm_cgroup("timerlat/", params->cgroup_name);
1107 if (!retval) {
1108 err_msg("Failed to move threads to cgroup\n");
1109 goto out_free;
1110 }
1111 }
1112
1113 if (params->dma_latency >= 0) {
1114 dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
1115 if (dma_latency_fd < 0) {
1116 err_msg("Could not set /dev/cpu_dma_latency.\n");
1117 goto out_free;
1118 }
1119 }
1120
1121 if (params->deepest_idle_state >= -1) {
1122 if (!have_libcpupower_support()) {
1123 err_msg("rtla built without libcpupower, --deepest-idle-state is not supported\n");
1124 goto out_free;
1125 }
1126
1127 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
1128
1129 for (i = 0; i < nr_cpus; i++) {
1130 if (params->cpus && !CPU_ISSET(i, ¶ms->monitored_cpus))
1131 continue;
1132 if (save_cpu_idle_disable_state(i) < 0) {
1133 err_msg("Could not save cpu idle state.\n");
1134 goto out_free;
1135 }
1136 if (set_deepest_cpu_idle_state(i, params->deepest_idle_state) < 0) {
1137 err_msg("Could not set deepest cpu idle state.\n");
1138 goto out_free;
1139 }
1140 }
1141 }
1142
1143 if (params->threshold_actions.present[ACTION_TRACE_OUTPUT] ||
1144 params->end_actions.present[ACTION_TRACE_OUTPUT]) {
1145 record = osnoise_init_trace_tool("timerlat");
1146 if (!record) {
1147 err_msg("Failed to enable the trace instance\n");
1148 goto out_free;
1149 }
1150 params->threshold_actions.trace_output_inst = record->trace.inst;
1151 params->end_actions.trace_output_inst = record->trace.inst;
1152
1153 if (params->events) {
1154 retval = trace_events_enable(&record->trace, params->events);
1155 if (retval)
1156 goto out_top;
1157 }
1158
1159 if (params->buffer_size > 0) {
1160 retval = trace_set_buffer_size(&record->trace, params->buffer_size);
1161 if (retval)
1162 goto out_top;
1163 }
1164 }
1165
1166 if (!params->no_aa) {
1167 aa = osnoise_init_tool("timerlat_aa");
1168 if (!aa)
1169 goto out_top;
1170
1171 retval = timerlat_aa_init(aa, params->dump_tasks);
1172 if (retval) {
1173 err_msg("Failed to enable the auto analysis instance\n");
1174 goto out_top;
1175 }
1176
1177 /* if it is re-using the main instance, there is no need to start it */
1178 if (aa != top) {
1179 retval = enable_timerlat(&aa->trace);
1180 if (retval) {
1181 err_msg("Failed to enable timerlat tracer\n");
1182 goto out_top;
1183 }
1184 }
1185 }
1186
1187 if (params->user_workload) {
1188 /* rtla asked to stop */
1189 params_u.should_run = 1;
1190 /* all threads left */
1191 params_u.stopped_running = 0;
1192
1193 params_u.set = ¶ms->monitored_cpus;
1194 if (params->set_sched)
1195 params_u.sched_param = ¶ms->sched_param;
1196 else
1197 params_u.sched_param = NULL;
1198
1199 params_u.cgroup_name = params->cgroup_name;
1200
1201 retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, ¶ms_u);
1202 if (retval)
1203 err_msg("Error creating timerlat user-space threads\n");
1204 }
1205
1206 if (params->warmup > 0) {
1207 debug_msg("Warming up for %d seconds\n", params->warmup);
1208 sleep(params->warmup);
1209 }
1210
1211 /*
1212 * Start the tracers here, after having set all instances.
1213 *
1214 * Let the trace instance start first for the case of hitting a stop
1215 * tracing while enabling other instances. The trace instance is the
1216 * one with most valuable information.
1217 */
1218 if (record)
1219 trace_instance_start(&record->trace);
1220 if (!params->no_aa)
1221 trace_instance_start(&aa->trace);
1222 if (params->mode == TRACING_MODE_TRACEFS) {
1223 trace_instance_start(trace);
1224 } else {
1225 retval = timerlat_bpf_attach();
1226 if (retval) {
1227 err_msg("Error attaching BPF program\n");
1228 goto out_top;
1229 }
1230 }
1231
1232 top->start_time = time(NULL);
1233 timerlat_top_set_signals(params);
1234
1235 if (params->mode == TRACING_MODE_TRACEFS)
1236 retval = timerlat_top_main_loop(top, record, aa, params, ¶ms_u);
1237 else
1238 retval = timerlat_top_bpf_main_loop(top, record, aa, params, ¶ms_u);
1239
1240 if (retval)
1241 goto out_top;
1242
1243 if (params->mode != TRACING_MODE_TRACEFS)
1244 timerlat_bpf_detach();
1245
1246 if (params->user_workload && !params_u.stopped_running) {
1247 params_u.should_run = 0;
1248 sleep(1);
1249 }
1250
1251 timerlat_print_stats(params, top);
1252
1253 actions_perform(¶ms->end_actions);
1254
1255 return_value = PASSED;
1256
1257 if (osnoise_trace_is_off(top, record) && !stop_tracing) {
1258 printf("rtla timerlat hit stop tracing\n");
1259
1260 if (!params->no_aa)
1261 timerlat_auto_analysis(params->stop_us, params->stop_total_us);
1262
1263 return_value = FAILED;
1264 } else if (params->aa_only) {
1265 /*
1266 * If the trace did not stop with --aa-only, at least print the
1267 * max known latency.
1268 */
1269 max_lat = tracefs_instance_file_read(trace->inst, "tracing_max_latency", NULL);
1270 if (max_lat) {
1271 printf(" Max latency was %s\n", max_lat);
1272 free(max_lat);
1273 }
1274 }
1275
1276 out_top:
1277 timerlat_aa_destroy();
1278 if (dma_latency_fd >= 0)
1279 close(dma_latency_fd);
1280 if (params->deepest_idle_state >= -1) {
1281 for (i = 0; i < nr_cpus; i++) {
1282 if (params->cpus && !CPU_ISSET(i, ¶ms->monitored_cpus))
1283 continue;
1284 restore_cpu_idle_disable_state(i);
1285 }
1286 }
1287 trace_events_destroy(&record->trace, params->events);
1288 params->events = NULL;
1289 out_free:
1290 timerlat_free_top(top->data);
1291 if (aa && aa != top)
1292 osnoise_destroy_tool(aa);
1293 osnoise_destroy_tool(record);
1294 osnoise_destroy_tool(top);
1295 actions_destroy(¶ms->threshold_actions);
1296 actions_destroy(¶ms->end_actions);
1297 if (params->mode != TRACING_MODE_TRACEFS)
1298 timerlat_bpf_destroy();
1299 free(params);
1300 free_cpu_idle_disable_states();
1301 out_exit:
1302 exit(return_value);
1303 }
1304