1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2021 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
4  */
5 
6 #include <getopt.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <signal.h>
10 #include <unistd.h>
11 #include <stdio.h>
12 #include <time.h>
13 
14 #include "utils.h"
15 #include "osnoise.h"
16 #include "timerlat.h"
17 
18 struct timerlat_top_params {
19 	char			*cpus;
20 	char			*monitored_cpus;
21 	char			*trace_output;
22 	unsigned long long	runtime;
23 	long long		stop_us;
24 	long long		stop_total_us;
25 	long long		timerlat_period_us;
26 	long long		print_stack;
27 	int			sleep_time;
28 	int			output_divisor;
29 	int			duration;
30 	int			quiet;
31 	int			set_sched;
32 	int			dma_latency;
33 	struct sched_attr	sched_param;
34 	struct trace_events	*events;
35 };
36 
37 struct timerlat_top_cpu {
38 	int			irq_count;
39 	int			thread_count;
40 
41 	unsigned long long	cur_irq;
42 	unsigned long long	min_irq;
43 	unsigned long long	sum_irq;
44 	unsigned long long	max_irq;
45 
46 	unsigned long long	cur_thread;
47 	unsigned long long	min_thread;
48 	unsigned long long	sum_thread;
49 	unsigned long long	max_thread;
50 };
51 
52 struct timerlat_top_data {
53 	struct timerlat_top_cpu	*cpu_data;
54 	int			nr_cpus;
55 };
56 
57 /*
58  * timerlat_free_top - free runtime data
59  */
60 static void
61 timerlat_free_top(struct timerlat_top_data *data)
62 {
63 	free(data->cpu_data);
64 	free(data);
65 }
66 
67 /*
68  * timerlat_alloc_histogram - alloc runtime data
69  */
70 static struct timerlat_top_data *timerlat_alloc_top(int nr_cpus)
71 {
72 	struct timerlat_top_data *data;
73 	int cpu;
74 
75 	data = calloc(1, sizeof(*data));
76 	if (!data)
77 		return NULL;
78 
79 	data->nr_cpus = nr_cpus;
80 
81 	/* one set of histograms per CPU */
82 	data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus);
83 	if (!data->cpu_data)
84 		goto cleanup;
85 
86 	/* set the min to max */
87 	for (cpu = 0; cpu < nr_cpus; cpu++) {
88 		data->cpu_data[cpu].min_irq = ~0;
89 		data->cpu_data[cpu].min_thread = ~0;
90 	}
91 
92 	return data;
93 
94 cleanup:
95 	timerlat_free_top(data);
96 	return NULL;
97 }
98 
99 /*
100  * timerlat_hist_update - record a new timerlat occurent on cpu, updating data
101  */
102 static void
103 timerlat_top_update(struct osnoise_tool *tool, int cpu,
104 		    unsigned long long thread,
105 		    unsigned long long latency)
106 {
107 	struct timerlat_top_data *data = tool->data;
108 	struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
109 
110 	if (!thread) {
111 		cpu_data->irq_count++;
112 		cpu_data->cur_irq = latency;
113 		update_min(&cpu_data->min_irq, &latency);
114 		update_sum(&cpu_data->sum_irq, &latency);
115 		update_max(&cpu_data->max_irq, &latency);
116 	} else {
117 		cpu_data->thread_count++;
118 		cpu_data->cur_thread = latency;
119 		update_min(&cpu_data->min_thread, &latency);
120 		update_sum(&cpu_data->sum_thread, &latency);
121 		update_max(&cpu_data->max_thread, &latency);
122 	}
123 }
124 
125 /*
126  * timerlat_top_handler - this is the handler for timerlat tracer events
127  */
128 static int
129 timerlat_top_handler(struct trace_seq *s, struct tep_record *record,
130 		     struct tep_event *event, void *context)
131 {
132 	struct trace_instance *trace = context;
133 	unsigned long long latency, thread;
134 	struct osnoise_tool *top;
135 	int cpu = record->cpu;
136 
137 	top = container_of(trace, struct osnoise_tool, trace);
138 
139 	tep_get_field_val(s, event, "context", record, &thread, 1);
140 	tep_get_field_val(s, event, "timer_latency", record, &latency, 1);
141 
142 	timerlat_top_update(top, cpu, thread, latency);
143 
144 	return 0;
145 }
146 
147 /*
148  * timerlat_top_header - print the header of the tool output
149  */
150 static void timerlat_top_header(struct osnoise_tool *top)
151 {
152 	struct timerlat_top_params *params = top->params;
153 	struct trace_seq *s = top->trace.seq;
154 	char duration[26];
155 
156 	get_duration(top->start_time, duration, sizeof(duration));
157 
158 	trace_seq_printf(s, "\033[2;37;40m");
159 	trace_seq_printf(s, "                                     Timer Latency                                              ");
160 	trace_seq_printf(s, "\033[0;0;0m");
161 	trace_seq_printf(s, "\n");
162 
163 	trace_seq_printf(s, "%-6s   |          IRQ Timer Latency (%s)        |         Thread Timer Latency (%s)\n", duration,
164 			params->output_divisor == 1 ? "ns" : "us",
165 			params->output_divisor == 1 ? "ns" : "us");
166 
167 	trace_seq_printf(s, "\033[2;30;47m");
168 	trace_seq_printf(s, "CPU COUNT      |      cur       min       avg       max |      cur       min       avg       max");
169 	trace_seq_printf(s, "\033[0;0;0m");
170 	trace_seq_printf(s, "\n");
171 }
172 
173 /*
174  * timerlat_top_print - prints the output of a given CPU
175  */
176 static void timerlat_top_print(struct osnoise_tool *top, int cpu)
177 {
178 
179 	struct timerlat_top_params *params = top->params;
180 	struct timerlat_top_data *data = top->data;
181 	struct timerlat_top_cpu *cpu_data = &data->cpu_data[cpu];
182 	int divisor = params->output_divisor;
183 	struct trace_seq *s = top->trace.seq;
184 
185 	if (divisor == 0)
186 		return;
187 
188 	/*
189 	 * Skip if no data is available: is this cpu offline?
190 	 */
191 	if (!cpu_data->irq_count && !cpu_data->thread_count)
192 		return;
193 
194 	/*
195 	 * Unless trace is being lost, IRQ counter is always the max.
196 	 */
197 	trace_seq_printf(s, "%3d #%-9d |", cpu, cpu_data->irq_count);
198 
199 	if (!cpu_data->irq_count) {
200 		trace_seq_printf(s, "        - ");
201 		trace_seq_printf(s, "        - ");
202 		trace_seq_printf(s, "        - ");
203 		trace_seq_printf(s, "        - |");
204 	} else {
205 		trace_seq_printf(s, "%9llu ", cpu_data->cur_irq / params->output_divisor);
206 		trace_seq_printf(s, "%9llu ", cpu_data->min_irq / params->output_divisor);
207 		trace_seq_printf(s, "%9llu ", (cpu_data->sum_irq / cpu_data->irq_count) / divisor);
208 		trace_seq_printf(s, "%9llu |", cpu_data->max_irq / divisor);
209 	}
210 
211 	if (!cpu_data->thread_count) {
212 		trace_seq_printf(s, "        - ");
213 		trace_seq_printf(s, "        - ");
214 		trace_seq_printf(s, "        - ");
215 		trace_seq_printf(s, "        -\n");
216 	} else {
217 		trace_seq_printf(s, "%9llu ", cpu_data->cur_thread / divisor);
218 		trace_seq_printf(s, "%9llu ", cpu_data->min_thread / divisor);
219 		trace_seq_printf(s, "%9llu ",
220 				(cpu_data->sum_thread / cpu_data->thread_count) / divisor);
221 		trace_seq_printf(s, "%9llu\n", cpu_data->max_thread / divisor);
222 	}
223 }
224 
225 /*
226  * clear_terminal - clears the output terminal
227  */
228 static void clear_terminal(struct trace_seq *seq)
229 {
230 	if (!config_debug)
231 		trace_seq_printf(seq, "\033c");
232 }
233 
234 /*
235  * timerlat_print_stats - print data for all cpus
236  */
237 static void
238 timerlat_print_stats(struct timerlat_top_params *params, struct osnoise_tool *top)
239 {
240 	struct trace_instance *trace = &top->trace;
241 	static int nr_cpus = -1;
242 	int i;
243 
244 	if (nr_cpus == -1)
245 		nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
246 
247 	if (!params->quiet)
248 		clear_terminal(trace->seq);
249 
250 	timerlat_top_header(top);
251 
252 	for (i = 0; i < nr_cpus; i++) {
253 		if (params->cpus && !params->monitored_cpus[i])
254 			continue;
255 		timerlat_top_print(top, i);
256 	}
257 
258 	trace_seq_do_printf(trace->seq);
259 	trace_seq_reset(trace->seq);
260 }
261 
262 /*
263  * timerlat_top_usage - prints timerlat top usage message
264  */
265 static void timerlat_top_usage(char *usage)
266 {
267 	int i;
268 
269 	static const char *const msg[] = {
270 		"",
271 		"  usage: rtla timerlat [top] [-h] [-q] [-a us] [-d s] [-D] [-n] [-p us] [-i us] [-T us] [-s us] \\",
272 		"	  [[-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] [-c cpu-list] \\",
273 		"	  [-P priority] [--dma-latency us]",
274 		"",
275 		"	  -h/--help: print this menu",
276 		"	  -a/--auto: set automatic trace mode, stopping the session if argument in us latency is hit",
277 		"	  -p/--period us: timerlat period in us",
278 		"	  -i/--irq us: stop trace if the irq latency is higher than the argument in us",
279 		"	  -T/--thread us: stop trace if the thread latency is higher than the argument in us",
280 		"	  -s/--stack us: save the stack trace at the IRQ if a thread latency is higher than the argument in us",
281 		"	  -c/--cpus cpus: run the tracer only on the given cpus",
282 		"	  -d/--duration time[m|h|d]: duration of the session in seconds",
283 		"	  -D/--debug: print debug info",
284 		"	  -t/--trace[=file]: save the stopped trace to [file|timerlat_trace.txt]",
285 		"	  -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
286 		"	     --filter <command>: enable a trace event filter to the previous -e event",
287 		"	     --trigger <command>: enable a trace event trigger to the previous -e event",
288 		"	  -n/--nano: display data in nanoseconds",
289 		"	  -q/--quiet print only a summary at the end",
290 		"	     --dma-latency us: set /dev/cpu_dma_latency latency <us> to reduce exit from idle latency",
291 		"	  -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
292 		"		o:prio - use SCHED_OTHER with prio",
293 		"		r:prio - use SCHED_RR with prio",
294 		"		f:prio - use SCHED_FIFO with prio",
295 		"		d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
296 		"						       in nanoseconds",
297 		NULL,
298 	};
299 
300 	if (usage)
301 		fprintf(stderr, "%s\n", usage);
302 
303 	fprintf(stderr, "rtla timerlat top: a per-cpu summary of the timer latency (version %s)\n",
304 			VERSION);
305 
306 	for (i = 0; msg[i]; i++)
307 		fprintf(stderr, "%s\n", msg[i]);
308 	exit(1);
309 }
310 
311 /*
312  * timerlat_top_parse_args - allocs, parse and fill the cmd line parameters
313  */
314 static struct timerlat_top_params
315 *timerlat_top_parse_args(int argc, char **argv)
316 {
317 	struct timerlat_top_params *params;
318 	struct trace_events *tevent;
319 	long long auto_thresh;
320 	int retval;
321 	int c;
322 
323 	params = calloc(1, sizeof(*params));
324 	if (!params)
325 		exit(1);
326 
327 	/* disabled by default */
328 	params->dma_latency = -1;
329 
330 	/* display data in microseconds */
331 	params->output_divisor = 1000;
332 
333 	while (1) {
334 		static struct option long_options[] = {
335 			{"auto",		required_argument,	0, 'a'},
336 			{"cpus",		required_argument,	0, 'c'},
337 			{"debug",		no_argument,		0, 'D'},
338 			{"duration",		required_argument,	0, 'd'},
339 			{"event",		required_argument,	0, 'e'},
340 			{"help",		no_argument,		0, 'h'},
341 			{"irq",			required_argument,	0, 'i'},
342 			{"nano",		no_argument,		0, 'n'},
343 			{"period",		required_argument,	0, 'p'},
344 			{"priority",		required_argument,	0, 'P'},
345 			{"quiet",		no_argument,		0, 'q'},
346 			{"stack",		required_argument,	0, 's'},
347 			{"thread",		required_argument,	0, 'T'},
348 			{"trace",		optional_argument,	0, 't'},
349 			{"trigger",		required_argument,	0, '0'},
350 			{"filter",		required_argument,	0, '1'},
351 			{"dma-latency",		required_argument,	0, '2'},
352 			{0, 0, 0, 0}
353 		};
354 
355 		/* getopt_long stores the option index here. */
356 		int option_index = 0;
357 
358 		c = getopt_long(argc, argv, "a:c:d:De:hi:np:P:qs:t::T:0:1:2:",
359 				 long_options, &option_index);
360 
361 		/* detect the end of the options. */
362 		if (c == -1)
363 			break;
364 
365 		switch (c) {
366 		case 'a':
367 			auto_thresh = get_llong_from_str(optarg);
368 
369 			/* set thread stop to auto_thresh */
370 			params->stop_total_us = auto_thresh;
371 
372 			/* get stack trace */
373 			params->print_stack = auto_thresh;
374 
375 			/* set trace */
376 			params->trace_output = "timerlat_trace.txt";
377 
378 			break;
379 		case 'c':
380 			retval = parse_cpu_list(optarg, &params->monitored_cpus);
381 			if (retval)
382 				timerlat_top_usage("\nInvalid -c cpu list\n");
383 			params->cpus = optarg;
384 			break;
385 		case 'D':
386 			config_debug = 1;
387 			break;
388 		case 'd':
389 			params->duration = parse_seconds_duration(optarg);
390 			if (!params->duration)
391 				timerlat_top_usage("Invalid -D duration\n");
392 			break;
393 		case 'e':
394 			tevent = trace_event_alloc(optarg);
395 			if (!tevent) {
396 				err_msg("Error alloc trace event");
397 				exit(EXIT_FAILURE);
398 			}
399 
400 			if (params->events)
401 				tevent->next = params->events;
402 			params->events = tevent;
403 			break;
404 		case 'h':
405 		case '?':
406 			timerlat_top_usage(NULL);
407 			break;
408 		case 'i':
409 			params->stop_us = get_llong_from_str(optarg);
410 			break;
411 		case 'n':
412 			params->output_divisor = 1;
413 			break;
414 		case 'p':
415 			params->timerlat_period_us = get_llong_from_str(optarg);
416 			if (params->timerlat_period_us > 1000000)
417 				timerlat_top_usage("Period longer than 1 s\n");
418 			break;
419 		case 'P':
420 			retval = parse_prio(optarg, &params->sched_param);
421 			if (retval == -1)
422 				timerlat_top_usage("Invalid -P priority");
423 			params->set_sched = 1;
424 			break;
425 		case 'q':
426 			params->quiet = 1;
427 			break;
428 		case 's':
429 			params->print_stack = get_llong_from_str(optarg);
430 			break;
431 		case 'T':
432 			params->stop_total_us = get_llong_from_str(optarg);
433 			break;
434 		case 't':
435 			if (optarg)
436 				/* skip = */
437 				params->trace_output = &optarg[1];
438 			else
439 				params->trace_output = "timerlat_trace.txt";
440 			break;
441 		case '0': /* trigger */
442 			if (params->events) {
443 				retval = trace_event_add_trigger(params->events, optarg);
444 				if (retval) {
445 					err_msg("Error adding trigger %s\n", optarg);
446 					exit(EXIT_FAILURE);
447 				}
448 			} else {
449 				timerlat_top_usage("--trigger requires a previous -e\n");
450 			}
451 			break;
452 		case '1': /* filter */
453 			if (params->events) {
454 				retval = trace_event_add_filter(params->events, optarg);
455 				if (retval) {
456 					err_msg("Error adding filter %s\n", optarg);
457 					exit(EXIT_FAILURE);
458 				}
459 			} else {
460 				timerlat_top_usage("--filter requires a previous -e\n");
461 			}
462 			break;
463 		case '2': /* dma-latency */
464 			params->dma_latency = get_llong_from_str(optarg);
465 			if (params->dma_latency < 0 || params->dma_latency > 10000) {
466 				err_msg("--dma-latency needs to be >= 0 and < 10000");
467 				exit(EXIT_FAILURE);
468 			}
469 			break;
470 		default:
471 			timerlat_top_usage("Invalid option");
472 		}
473 	}
474 
475 	if (geteuid()) {
476 		err_msg("rtla needs root permission\n");
477 		exit(EXIT_FAILURE);
478 	}
479 
480 	return params;
481 }
482 
483 /*
484  * timerlat_top_apply_config - apply the top configs to the initialized tool
485  */
486 static int
487 timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *params)
488 {
489 	int retval;
490 
491 	if (!params->sleep_time)
492 		params->sleep_time = 1;
493 
494 	if (params->cpus) {
495 		retval = osnoise_set_cpus(top->context, params->cpus);
496 		if (retval) {
497 			err_msg("Failed to apply CPUs config\n");
498 			goto out_err;
499 		}
500 	}
501 
502 	if (params->stop_us) {
503 		retval = osnoise_set_stop_us(top->context, params->stop_us);
504 		if (retval) {
505 			err_msg("Failed to set stop us\n");
506 			goto out_err;
507 		}
508 	}
509 
510 	if (params->stop_total_us) {
511 		retval = osnoise_set_stop_total_us(top->context, params->stop_total_us);
512 		if (retval) {
513 			err_msg("Failed to set stop total us\n");
514 			goto out_err;
515 		}
516 	}
517 
518 
519 	if (params->timerlat_period_us) {
520 		retval = osnoise_set_timerlat_period_us(top->context, params->timerlat_period_us);
521 		if (retval) {
522 			err_msg("Failed to set timerlat period\n");
523 			goto out_err;
524 		}
525 	}
526 
527 
528 	if (params->print_stack) {
529 		retval = osnoise_set_print_stack(top->context, params->print_stack);
530 		if (retval) {
531 			err_msg("Failed to set print stack\n");
532 			goto out_err;
533 		}
534 	}
535 
536 	return 0;
537 
538 out_err:
539 	return -1;
540 }
541 
542 /*
543  * timerlat_init_top - initialize a timerlat top tool with parameters
544  */
545 static struct osnoise_tool
546 *timerlat_init_top(struct timerlat_top_params *params)
547 {
548 	struct osnoise_tool *top;
549 	int nr_cpus;
550 
551 	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
552 
553 	top = osnoise_init_tool("timerlat_top");
554 	if (!top)
555 		return NULL;
556 
557 	top->data = timerlat_alloc_top(nr_cpus);
558 	if (!top->data)
559 		goto out_err;
560 
561 	top->params = params;
562 
563 	tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat",
564 				   timerlat_top_handler, top);
565 
566 	return top;
567 
568 out_err:
569 	osnoise_destroy_tool(top);
570 	return NULL;
571 }
572 
573 static int stop_tracing;
574 static void stop_top(int sig)
575 {
576 	stop_tracing = 1;
577 }
578 
579 /*
580  * timerlat_top_set_signals - handles the signal to stop the tool
581  */
582 static void
583 timerlat_top_set_signals(struct timerlat_top_params *params)
584 {
585 	signal(SIGINT, stop_top);
586 	if (params->duration) {
587 		signal(SIGALRM, stop_top);
588 		alarm(params->duration);
589 	}
590 }
591 
592 int timerlat_top_main(int argc, char *argv[])
593 {
594 	struct timerlat_top_params *params;
595 	struct osnoise_tool *record = NULL;
596 	struct osnoise_tool *top = NULL;
597 	struct trace_instance *trace;
598 	int dma_latency_fd = -1;
599 	int return_value = 1;
600 	int retval;
601 
602 	params = timerlat_top_parse_args(argc, argv);
603 	if (!params)
604 		exit(1);
605 
606 	top = timerlat_init_top(params);
607 	if (!top) {
608 		err_msg("Could not init osnoise top\n");
609 		goto out_exit;
610 	}
611 
612 	retval = timerlat_top_apply_config(top, params);
613 	if (retval) {
614 		err_msg("Could not apply config\n");
615 		goto out_top;
616 	}
617 
618 	trace = &top->trace;
619 
620 	retval = enable_timerlat(trace);
621 	if (retval) {
622 		err_msg("Failed to enable timerlat tracer\n");
623 		goto out_top;
624 	}
625 
626 	if (params->set_sched) {
627 		retval = set_comm_sched_attr("timerlat/", &params->sched_param);
628 		if (retval) {
629 			err_msg("Failed to set sched parameters\n");
630 			goto out_top;
631 		}
632 	}
633 
634 	if (params->dma_latency >= 0) {
635 		dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
636 		if (dma_latency_fd < 0) {
637 			err_msg("Could not set /dev/cpu_dma_latency.\n");
638 			goto out_top;
639 		}
640 	}
641 
642 	trace_instance_start(trace);
643 
644 	if (params->trace_output) {
645 		record = osnoise_init_trace_tool("timerlat");
646 		if (!record) {
647 			err_msg("Failed to enable the trace instance\n");
648 			goto out_top;
649 		}
650 
651 		if (params->events) {
652 			retval = trace_events_enable(&record->trace, params->events);
653 			if (retval)
654 				goto out_top;
655 		}
656 
657 		trace_instance_start(&record->trace);
658 	}
659 
660 	top->start_time = time(NULL);
661 	timerlat_top_set_signals(params);
662 
663 	while (!stop_tracing) {
664 		sleep(params->sleep_time);
665 
666 		retval = tracefs_iterate_raw_events(trace->tep,
667 						    trace->inst,
668 						    NULL,
669 						    0,
670 						    collect_registered_events,
671 						    trace);
672 		if (retval < 0) {
673 			err_msg("Error iterating on events\n");
674 			goto out_top;
675 		}
676 
677 		if (!params->quiet)
678 			timerlat_print_stats(params, top);
679 
680 		if (trace_is_off(&top->trace, &record->trace))
681 			break;
682 
683 	}
684 
685 	timerlat_print_stats(params, top);
686 
687 	return_value = 0;
688 
689 	if (trace_is_off(&top->trace, &record->trace)) {
690 		printf("rtla timelat hit stop tracing\n");
691 		if (params->trace_output) {
692 			printf("  Saving trace to %s\n", params->trace_output);
693 			save_trace_to_file(record->trace.inst, params->trace_output);
694 		}
695 	}
696 
697 out_top:
698 	if (dma_latency_fd >= 0)
699 		close(dma_latency_fd);
700 	trace_events_destroy(&record->trace, params->events);
701 	params->events = NULL;
702 	timerlat_free_top(top->data);
703 	osnoise_destroy_tool(record);
704 	osnoise_destroy_tool(top);
705 	free(params);
706 out_exit:
707 	exit(return_value);
708 }
709