tools/tracing/rtla/src/timerlat_top.c

   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
  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  */
  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
 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
 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  */
 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  */
 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  */
 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
 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, &params->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  */
 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
 379         if (usage)
 380                 exit(EXIT_FAILURE);
 381
 382         exit(EXIT_SUCCESS);
 383 }
 384
 385 /*
 386  * timerlat_top_parse_args - allocs, parse and fill the cmd line parameters
 387  */
 388 static struct timerlat_top_params
 389 *timerlat_top_parse_args(int argc, char **argv)
 390 {
 391         struct timerlat_top_params *params;
 392         struct trace_events *tevent;
 393         long long auto_thresh;
 394         int retval;
 395         int c;
 396
 397         params = calloc(1, sizeof(*params));
 398         if (!params)
 399                 exit(1);
 400
 401         /* disabled by default */
 402         params->dma_latency = -1;
 403
 404         /* display data in microseconds */
 405         params->output_divisor = 1000;
 406
 407         while (1) {
 408                 static struct option long_options[] = {
 409                         {"auto",                required_argument,      0, 'a'},
 410                         {"cpus",                required_argument,      0, 'c'},
 411                         {"cgroup",              optional_argument,      0, 'C'},
 412                         {"debug",               no_argument,            0, 'D'},
 413                         {"duration",            required_argument,      0, 'd'},
 414                         {"event",               required_argument,      0, 'e'},
 415                         {"help",                no_argument,            0, 'h'},
 416                         {"house-keeping",       required_argument,      0, 'H'},
 417                         {"irq",                 required_argument,      0, 'i'},
 418                         {"nano",                no_argument,            0, 'n'},
 419                         {"period",              required_argument,      0, 'p'},
 420                         {"priority",            required_argument,      0, 'P'},
 421                         {"quiet",               no_argument,            0, 'q'},
 422                         {"stack",               required_argument,      0, 's'},
 423                         {"thread",              required_argument,      0, 'T'},
 424                         {"trace",               optional_argument,      0, 't'},
 425                         {"user-threads",        no_argument,            0, 'u'},
 426                         {"trigger",             required_argument,      0, '0'},
 427                         {"filter",              required_argument,      0, '1'},
 428                         {"dma-latency",         required_argument,      0, '2'},
 429                         {"no-aa",               no_argument,            0, '3'},
 430                         {"dump-tasks",          no_argument,            0, '4'},
 431                         {"aa-only",             required_argument,      0, '5'},
 432                         {0, 0, 0, 0}
 433                 };
 434
 435                 /* getopt_long stores the option index here. */
 436                 int option_index = 0;
 437
 438                 c = getopt_long(argc, argv, "a:c:C::d:De:hH:i:np:P:qs:t::T:u0:1:2:345:",
 439                                  long_options, &option_index);
 440
 441                 /* detect the end of the options. */
 442                 if (c == -1)
 443                         break;
 444
 445                 switch (c) {
 446                 case 'a':
 447                         auto_thresh = get_llong_from_str(optarg);
 448
 449                         /* set thread stop to auto_thresh */
 450                         params->stop_total_us = auto_thresh;
 451                         params->stop_us = auto_thresh;
 452
 453                         /* get stack trace */
 454                         params->print_stack = auto_thresh;
 455
 456                         /* set trace */
 457                         params->trace_output = "timerlat_trace.txt";
 458                         break;
 459                 case '5':
 460                         /* it is here because it is similar to -a */
 461                         auto_thresh = get_llong_from_str(optarg);
 462
 463                         /* set thread stop to auto_thresh */
 464                         params->stop_total_us = auto_thresh;
 465                         params->stop_us = auto_thresh;
 466
 467                         /* get stack trace */
 468                         params->print_stack = auto_thresh;
 469
 470                         /* set aa_only to avoid parsing the trace */
 471                         params->aa_only = 1;
 472                         break;
 473                 case 'c':
 474                         retval = parse_cpu_set(optarg, &params->monitored_cpus);
 475                         if (retval)
 476                                 timerlat_top_usage("\nInvalid -c cpu list\n");
 477                         params->cpus = optarg;
 478                         break;
 479                 case 'C':
 480                         params->cgroup = 1;
 481                         if (!optarg) {
 482                                 /* will inherit this cgroup */
 483                                 params->cgroup_name = NULL;
 484                         } else if (*optarg == '=') {
 485                                 /* skip the = */
 486                                 params->cgroup_name = ++optarg;
 487                         }
 488                         break;
 489                 case 'D':
 490                         config_debug = 1;
 491                         break;
 492                 case 'd':
 493                         params->duration = parse_seconds_duration(optarg);
 494                         if (!params->duration)
 495                                 timerlat_top_usage("Invalid -D duration\n");
 496                         break;
 497                 case 'e':
 498                         tevent = trace_event_alloc(optarg);
 499                         if (!tevent) {
 500                                 err_msg("Error alloc trace event");
 501                                 exit(EXIT_FAILURE);
 502                         }
 503
 504                         if (params->events)
 505                                 tevent->next = params->events;
 506                         params->events = tevent;
 507                         break;
 508                 case 'h':
 509                 case '?':
 510                         timerlat_top_usage(NULL);
 511                         break;
 512                 case 'H':
 513                         params->hk_cpus = 1;
 514                         retval = parse_cpu_set(optarg, &params->hk_cpu_set);
 515                         if (retval) {
 516                                 err_msg("Error parsing house keeping CPUs\n");
 517                                 exit(EXIT_FAILURE);
 518                         }
 519                         break;
 520                 case 'i':
 521                         params->stop_us = get_llong_from_str(optarg);
 522                         break;
 523                 case 'n':
 524                         params->output_divisor = 1;
 525                         break;
 526                 case 'p':
 527                         params->timerlat_period_us = get_llong_from_str(optarg);
 528                         if (params->timerlat_period_us > 1000000)
 529                                 timerlat_top_usage("Period longer than 1 s\n");
 530                         break;
 531                 case 'P':
 532                         retval = parse_prio(optarg, &params->sched_param);
 533                         if (retval == -1)
 534                                 timerlat_top_usage("Invalid -P priority");
 535                         params->set_sched = 1;
 536                         break;
 537                 case 'q':
 538                         params->quiet = 1;
 539                         break;
 540                 case 's':
 541                         params->print_stack = get_llong_from_str(optarg);
 542                         break;
 543                 case 'T':
 544                         params->stop_total_us = get_llong_from_str(optarg);
 545                         break;
 546                 case 't':
 547                         if (optarg)
 548                                 /* skip = */
 549                                 params->trace_output = &optarg[1];
 550                         else
 551                                 params->trace_output = "timerlat_trace.txt";
 552
 553                         break;
 554                 case 'u':
 555                         params->user_top = true;
 556                         break;
 557                 case '0': /* trigger */
 558                         if (params->events) {
 559                                 retval = trace_event_add_trigger(params->events, optarg);
 560                                 if (retval) {
 561                                         err_msg("Error adding trigger %s\n", optarg);
 562                                         exit(EXIT_FAILURE);
 563                                 }
 564                         } else {
 565                                 timerlat_top_usage("--trigger requires a previous -e\n");
 566                         }
 567                         break;
 568                 case '1': /* filter */
 569                         if (params->events) {
 570                                 retval = trace_event_add_filter(params->events, optarg);
 571                                 if (retval) {
 572                                         err_msg("Error adding filter %s\n", optarg);
 573                                         exit(EXIT_FAILURE);
 574                                 }
 575                         } else {
 576                                 timerlat_top_usage("--filter requires a previous -e\n");
 577                         }
 578                         break;
 579                 case '2': /* dma-latency */
 580                         params->dma_latency = get_llong_from_str(optarg);
 581                         if (params->dma_latency < 0 || params->dma_latency > 10000) {
 582                                 err_msg("--dma-latency needs to be >= 0 and < 10000");
 583                                 exit(EXIT_FAILURE);
 584                         }
 585                         break;
 586                 case '3': /* no-aa */
 587                         params->no_aa = 1;
 588                         break;
 589                 case '4':
 590                         params->dump_tasks = 1;
 591                         break;
 592                 default:
 593                         timerlat_top_usage("Invalid option");
 594                 }
 595         }
 596
 597         if (geteuid()) {
 598                 err_msg("rtla needs root permission\n");
 599                 exit(EXIT_FAILURE);
 600         }
 601
 602         /*
 603          * Auto analysis only happens if stop tracing, thus:
 604          */
 605         if (!params->stop_us && !params->stop_total_us)
 606                 params->no_aa = 1;
 607
 608         if (params->no_aa && params->aa_only)
 609                 timerlat_top_usage("--no-aa and --aa-only are mutually exclusive!");
 610
 611         return params;
 612 }
 613
 614 /*
 615  * timerlat_top_apply_config - apply the top configs to the initialized tool
 616  */
 617 static int
 618 timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *params)
 619 {
 620         int retval;
 621         int i;
 622
 623         if (!params->sleep_time)
 624                 params->sleep_time = 1;
 625
 626         if (params->cpus) {
 627                 retval = osnoise_set_cpus(top->context, params->cpus);
 628                 if (retval) {
 629                         err_msg("Failed to apply CPUs config\n");
 630                         goto out_err;
 631                 }
 632         } else {
 633                 for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
 634                         CPU_SET(i, &params->monitored_cpus);
 635         }
 636
 637         if (params->stop_us) {
 638                 retval = osnoise_set_stop_us(top->context, params->stop_us);
 639                 if (retval) {
 640                         err_msg("Failed to set stop us\n");
 641                         goto out_err;
 642                 }
 643         }
 644
 645         if (params->stop_total_us) {
 646                 retval = osnoise_set_stop_total_us(top->context, params->stop_total_us);
 647                 if (retval) {
 648                         err_msg("Failed to set stop total us\n");
 649                         goto out_err;
 650                 }
 651         }
 652
 653
 654         if (params->timerlat_period_us) {
 655                 retval = osnoise_set_timerlat_period_us(top->context, params->timerlat_period_us);
 656                 if (retval) {
 657                         err_msg("Failed to set timerlat period\n");
 658                         goto out_err;
 659                 }
 660         }
 661
 662
 663         if (params->print_stack) {
 664                 retval = osnoise_set_print_stack(top->context, params->print_stack);
 665                 if (retval) {
 666                         err_msg("Failed to set print stack\n");
 667                         goto out_err;
 668                 }
 669         }
 670
 671         if (params->hk_cpus) {
 672                 retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
 673                                            &params->hk_cpu_set);
 674                 if (retval == -1) {
 675                         err_msg("Failed to set rtla to the house keeping CPUs\n");
 676                         goto out_err;
 677                 }
 678         } else if (params->cpus) {
 679                 /*
 680                  * Even if the user do not set a house-keeping CPU, try to
 681                  * move rtla to a CPU set different to the one where the user
 682                  * set the workload to run.
 683                  *
 684                  * No need to check results as this is an automatic attempt.
 685                  */
 686                 auto_house_keeping(&params->monitored_cpus);
 687         }
 688
 689         if (params->user_top) {
 690                 retval = osnoise_set_workload(top->context, 0);
 691                 if (retval) {
 692                         err_msg("Failed to set OSNOISE_WORKLOAD option\n");
 693                         goto out_err;
 694                 }
 695         }
 696
 697         return 0;
 698
 699 out_err:
 700         return -1;
 701 }
 702
 703 /*
 704  * timerlat_init_top - initialize a timerlat top tool with parameters
 705  */
 706 static struct osnoise_tool
 707 *timerlat_init_top(struct timerlat_top_params *params)
 708 {
 709         struct osnoise_tool *top;
 710         int nr_cpus;
 711
 712         nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 713
 714         top = osnoise_init_tool("timerlat_top");
 715         if (!top)
 716                 return NULL;
 717
 718         top->data = timerlat_alloc_top(nr_cpus);
 719         if (!top->data)
 720                 goto out_err;
 721
 722         top->params = params;
 723
 724         tep_register_event_handler(top->trace.tep, -1, "ftrace", "timerlat",
 725                                    timerlat_top_handler, top);
 726
 727         return top;
 728
 729 out_err:
 730         osnoise_destroy_tool(top);
 731         return NULL;
 732 }
 733
 734 static int stop_tracing;
 735 static void stop_top(int sig)
 736 {
 737         stop_tracing = 1;
 738 }
 739
 740 /*
 741  * timerlat_top_set_signals - handles the signal to stop the tool
 742  */
 743 static void
 744 timerlat_top_set_signals(struct timerlat_top_params *params)
 745 {
 746         signal(SIGINT, stop_top);
 747         if (params->duration) {
 748                 signal(SIGALRM, stop_top);
 749                 alarm(params->duration);
 750         }
 751 }
 752
 753 int timerlat_top_main(int argc, char *argv[])
 754 {
 755         struct timerlat_top_params *params;
 756         struct osnoise_tool *record = NULL;
 757         struct timerlat_u_params params_u;
 758         struct osnoise_tool *top = NULL;
 759         struct osnoise_tool *aa = NULL;
 760         struct trace_instance *trace;
 761         int dma_latency_fd = -1;
 762         pthread_t timerlat_u;
 763         int return_value = 1;
 764         char *max_lat;
 765         int retval;
 766
 767         params = timerlat_top_parse_args(argc, argv);
 768         if (!params)
 769                 exit(1);
 770
 771         top = timerlat_init_top(params);
 772         if (!top) {
 773                 err_msg("Could not init osnoise top\n");
 774                 goto out_exit;
 775         }
 776
 777         retval = timerlat_top_apply_config(top, params);
 778         if (retval) {
 779                 err_msg("Could not apply config\n");
 780                 goto out_free;
 781         }
 782
 783         trace = &top->trace;
 784
 785         retval = enable_timerlat(trace);
 786         if (retval) {
 787                 err_msg("Failed to enable timerlat tracer\n");
 788                 goto out_free;
 789         }
 790
 791         if (params->set_sched) {
 792                 retval = set_comm_sched_attr("timerlat/", &params->sched_param);
 793                 if (retval) {
 794                         err_msg("Failed to set sched parameters\n");
 795                         goto out_free;
 796                 }
 797         }
 798
 799         if (params->cgroup && !params->user_top) {
 800                 retval = set_comm_cgroup("timerlat/", params->cgroup_name);
 801                 if (!retval) {
 802                         err_msg("Failed to move threads to cgroup\n");
 803                         goto out_free;
 804                 }
 805         }
 806
 807         if (params->dma_latency >= 0) {
 808                 dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
 809                 if (dma_latency_fd < 0) {
 810                         err_msg("Could not set /dev/cpu_dma_latency.\n");
 811                         goto out_free;
 812                 }
 813         }
 814
 815         if (params->trace_output) {
 816                 record = osnoise_init_trace_tool("timerlat");
 817                 if (!record) {
 818                         err_msg("Failed to enable the trace instance\n");
 819                         goto out_free;
 820                 }
 821
 822                 if (params->events) {
 823                         retval = trace_events_enable(&record->trace, params->events);
 824                         if (retval)
 825                                 goto out_top;
 826                 }
 827         }
 828
 829         if (!params->no_aa) {
 830                 if (params->aa_only) {
 831                         /* as top is not used for display, use it for aa */
 832                         aa = top;
 833                 } else  {
 834                         /* otherwise, a new instance is needed */
 835                         aa = osnoise_init_tool("timerlat_aa");
 836                         if (!aa)
 837                                 goto out_top;
 838                 }
 839
 840                 retval = timerlat_aa_init(aa, params->dump_tasks);
 841                 if (retval) {
 842                         err_msg("Failed to enable the auto analysis instance\n");
 843                         goto out_top;
 844                 }
 845
 846                 /* if it is re-using the main instance, there is no need to start it */
 847                 if (aa != top) {
 848                         retval = enable_timerlat(&aa->trace);
 849                         if (retval) {
 850                                 err_msg("Failed to enable timerlat tracer\n");
 851                                 goto out_top;
 852                         }
 853                 }
 854         }
 855
 856         /*
 857          * Start the tracers here, after having set all instances.
 858          *
 859          * Let the trace instance start first for the case of hitting a stop
 860          * tracing while enabling other instances. The trace instance is the
 861          * one with most valuable information.
 862          */
 863         if (params->trace_output)
 864                 trace_instance_start(&record->trace);
 865         if (!params->no_aa && aa != top)
 866                 trace_instance_start(&aa->trace);
 867         trace_instance_start(trace);
 868
 869         top->start_time = time(NULL);
 870         timerlat_top_set_signals(params);
 871
 872         if (params->user_top) {
 873                 /* rtla asked to stop */
 874                 params_u.should_run = 1;
 875                 /* all threads left */
 876                 params_u.stopped_running = 0;
 877
 878                 params_u.set = &params->monitored_cpus;
 879                 if (params->set_sched)
 880                         params_u.sched_param = &params->sched_param;
 881                 else
 882                         params_u.sched_param = NULL;
 883
 884                 params_u.cgroup_name = params->cgroup_name;
 885
 886                 retval = pthread_create(&timerlat_u, NULL, timerlat_u_dispatcher, &params_u);
 887                 if (retval)
 888                         err_msg("Error creating timerlat user-space threads\n");
 889         }
 890
 891         while (!stop_tracing) {
 892                 sleep(params->sleep_time);
 893
 894                 if (params->aa_only && !trace_is_off(&top->trace, &record->trace))
 895                         continue;
 896
 897                 retval = tracefs_iterate_raw_events(trace->tep,
 898                                                     trace->inst,
 899                                                     NULL,
 900                                                     0,
 901                                                     collect_registered_events,
 902                                                     trace);
 903                 if (retval < 0) {
 904                         err_msg("Error iterating on events\n");
 905                         goto out_top;
 906                 }
 907
 908                 if (!params->quiet)
 909                         timerlat_print_stats(params, top);
 910
 911                 if (trace_is_off(&top->trace, &record->trace))
 912                         break;
 913
 914                 /* is there still any user-threads ? */
 915                 if (params->user_top) {
 916                         if (params_u.stopped_running) {
 917                                 debug_msg("timerlat user space threads stopped!\n");
 918                                 break;
 919                         }
 920                 }
 921         }
 922
 923         if (params->user_top && !params_u.stopped_running) {
 924                 params_u.should_run = 0;
 925                 sleep(1);
 926         }
 927
 928         timerlat_print_stats(params, top);
 929
 930         return_value = 0;
 931
 932         if (trace_is_off(&top->trace, &record->trace)) {
 933                 printf("rtla timerlat hit stop tracing\n");
 934
 935                 if (!params->no_aa)
 936                         timerlat_auto_analysis(params->stop_us, params->stop_total_us);
 937
 938                 if (params->trace_output) {
 939                         printf("  Saving trace to %s\n", params->trace_output);
 940                         save_trace_to_file(record->trace.inst, params->trace_output);
 941                 }
 942         } else if (params->aa_only) {
 943                 /*
 944                  * If the trace did not stop with --aa-only, at least print the
 945                  * max known latency.
 946                  */
 947                 max_lat = tracefs_instance_file_read(trace->inst, "tracing_max_latency", NULL);
 948                 if (max_lat) {
 949                         printf("  Max latency was %s\n", max_lat);
 950                         free(max_lat);
 951                 }
 952         }
 953
 954 out_top:
 955         timerlat_aa_destroy();
 956         if (dma_latency_fd >= 0)
 957                 close(dma_latency_fd);
 958         trace_events_destroy(&record->trace, params->events);
 959         params->events = NULL;
 960 out_free:
 961         timerlat_free_top(top->data);
 962         if (aa && aa != top)
 963                 osnoise_destroy_tool(aa);
 964         osnoise_destroy_tool(record);
 965         osnoise_destroy_tool(top);
 966         free(params);
 967 out_exit:
 968         exit(return_value);
 969 }