tools/tracing/rtla/src/osnoise_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 <sched.h>
  15
  16 #include "osnoise.h"
  17 #include "utils.h"
  18
  19 enum osnoise_mode {
  20         MODE_OSNOISE = 0,
  21         MODE_HWNOISE
  22 };
  23
  24 /*
  25  * osnoise top parameters
  26  */
  27 struct osnoise_top_params {
  28         char                    *cpus;
  29         cpu_set_t               monitored_cpus;
  30         char                    *trace_output;
  31         char                    *cgroup_name;
  32         unsigned long long      runtime;
  33         unsigned long long      period;
  34         long long               threshold;
  35         long long               stop_us;
  36         long long               stop_total_us;
  37         int                     sleep_time;
  38         int                     duration;
  39         int                     quiet;
  40         int                     set_sched;
  41         int                     cgroup;
  42         int                     hk_cpus;
  43         cpu_set_t               hk_cpu_set;
  44         struct sched_attr       sched_param;
  45         struct trace_events     *events;
  46         enum osnoise_mode       mode;
  47 };
  48
  49 struct osnoise_top_cpu {
  50         unsigned long long      sum_runtime;
  51         unsigned long long      sum_noise;
  52         unsigned long long      max_noise;
  53         unsigned long long      max_sample;
  54
  55         unsigned long long      hw_count;
  56         unsigned long long      nmi_count;
  57         unsigned long long      irq_count;
  58         unsigned long long      softirq_count;
  59         unsigned long long      thread_count;
  60
  61         int                     sum_cycles;
  62 };
  63
  64 struct osnoise_top_data {
  65         struct osnoise_top_cpu  *cpu_data;
  66         int                     nr_cpus;
  67 };
  68
  69 /*
  70  * osnoise_free_top - free runtime data
  71  */
  72 static void
  73 osnoise_free_top(struct osnoise_top_data *data)
  74 {
  75         free(data->cpu_data);
  76         free(data);
  77 }
  78
  79 /*
  80  * osnoise_alloc_histogram - alloc runtime data
  81  */
  82 static struct osnoise_top_data *osnoise_alloc_top(int nr_cpus)
  83 {
  84         struct osnoise_top_data *data;
  85
  86         data = calloc(1, sizeof(*data));
  87         if (!data)
  88                 return NULL;
  89
  90         data->nr_cpus = nr_cpus;
  91
  92         /* one set of histograms per CPU */
  93         data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus);
  94         if (!data->cpu_data)
  95                 goto cleanup;
  96
  97         return data;
  98
  99 cleanup:
 100         osnoise_free_top(data);
 101         return NULL;
 102 }
 103
 104 /*
 105  * osnoise_top_handler - this is the handler for osnoise tracer events
 106  */
 107 static int
 108 osnoise_top_handler(struct trace_seq *s, struct tep_record *record,
 109                     struct tep_event *event, void *context)
 110 {
 111         struct trace_instance *trace = context;
 112         struct osnoise_tool *tool;
 113         unsigned long long val;
 114         struct osnoise_top_cpu *cpu_data;
 115         struct osnoise_top_data *data;
 116         int cpu = record->cpu;
 117
 118         tool = container_of(trace, struct osnoise_tool, trace);
 119
 120         data = tool->data;
 121         cpu_data = &data->cpu_data[cpu];
 122
 123         cpu_data->sum_cycles++;
 124
 125         tep_get_field_val(s, event, "runtime", record, &val, 1);
 126         update_sum(&cpu_data->sum_runtime, &val);
 127
 128         tep_get_field_val(s, event, "noise", record, &val, 1);
 129         update_max(&cpu_data->max_noise, &val);
 130         update_sum(&cpu_data->sum_noise, &val);
 131
 132         tep_get_field_val(s, event, "max_sample", record, &val, 1);
 133         update_max(&cpu_data->max_sample, &val);
 134
 135         tep_get_field_val(s, event, "hw_count", record, &val, 1);
 136         update_sum(&cpu_data->hw_count, &val);
 137
 138         tep_get_field_val(s, event, "nmi_count", record, &val, 1);
 139         update_sum(&cpu_data->nmi_count, &val);
 140
 141         tep_get_field_val(s, event, "irq_count", record, &val, 1);
 142         update_sum(&cpu_data->irq_count, &val);
 143
 144         tep_get_field_val(s, event, "softirq_count", record, &val, 1);
 145         update_sum(&cpu_data->softirq_count, &val);
 146
 147         tep_get_field_val(s, event, "thread_count", record, &val, 1);
 148         update_sum(&cpu_data->thread_count, &val);
 149
 150         return 0;
 151 }
 152
 153 /*
 154  * osnoise_top_header - print the header of the tool output
 155  */
 156 static void osnoise_top_header(struct osnoise_tool *top)
 157 {
 158         struct osnoise_top_params *params = top->params;
 159         struct trace_seq *s = top->trace.seq;
 160         char duration[26];
 161
 162         get_duration(top->start_time, duration, sizeof(duration));
 163
 164         trace_seq_printf(s, "\033[2;37;40m");
 165         trace_seq_printf(s, "                                          ");
 166
 167         if (params->mode == MODE_OSNOISE) {
 168                 trace_seq_printf(s, "Operating System Noise");
 169                 trace_seq_printf(s, "                                       ");
 170         } else if (params->mode == MODE_HWNOISE) {
 171                 trace_seq_printf(s, "Hardware-related Noise");
 172         }
 173
 174         trace_seq_printf(s, "                                   ");
 175         trace_seq_printf(s, "\033[0;0;0m");
 176         trace_seq_printf(s, "\n");
 177
 178         trace_seq_printf(s, "duration: %9s | time is in us\n", duration);
 179
 180         trace_seq_printf(s, "\033[2;30;47m");
 181         trace_seq_printf(s, "CPU Period       Runtime ");
 182         trace_seq_printf(s, "       Noise ");
 183         trace_seq_printf(s, " %% CPU Aval ");
 184         trace_seq_printf(s, "  Max Noise   Max Single ");
 185         trace_seq_printf(s, "         HW          NMI");
 186
 187         if (params->mode == MODE_HWNOISE)
 188                 goto eol;
 189
 190         trace_seq_printf(s, "          IRQ      Softirq       Thread");
 191
 192 eol:
 193         trace_seq_printf(s, "\033[0;0;0m");
 194         trace_seq_printf(s, "\n");
 195 }
 196
 197 /*
 198  * clear_terminal - clears the output terminal
 199  */
 200 static void clear_terminal(struct trace_seq *seq)
 201 {
 202         if (!config_debug)
 203                 trace_seq_printf(seq, "\033c");
 204 }
 205
 206 /*
 207  * osnoise_top_print - prints the output of a given CPU
 208  */
 209 static void osnoise_top_print(struct osnoise_tool *tool, int cpu)
 210 {
 211         struct osnoise_top_params *params = tool->params;
 212         struct trace_seq *s = tool->trace.seq;
 213         struct osnoise_top_cpu *cpu_data;
 214         struct osnoise_top_data *data;
 215         int percentage;
 216         int decimal;
 217
 218         data = tool->data;
 219         cpu_data = &data->cpu_data[cpu];
 220
 221         if (!cpu_data->sum_runtime)
 222                 return;
 223
 224         percentage = ((cpu_data->sum_runtime - cpu_data->sum_noise) * 10000000)
 225                         / cpu_data->sum_runtime;
 226         decimal = percentage % 100000;
 227         percentage = percentage / 100000;
 228
 229         trace_seq_printf(s, "%3d #%-6d %12llu ", cpu, cpu_data->sum_cycles, cpu_data->sum_runtime);
 230         trace_seq_printf(s, "%12llu ", cpu_data->sum_noise);
 231         trace_seq_printf(s, "  %3d.%05d", percentage, decimal);
 232         trace_seq_printf(s, "%12llu %12llu", cpu_data->max_noise, cpu_data->max_sample);
 233
 234         trace_seq_printf(s, "%12llu ", cpu_data->hw_count);
 235         trace_seq_printf(s, "%12llu ", cpu_data->nmi_count);
 236
 237         if (params->mode == MODE_HWNOISE) {
 238                 trace_seq_printf(s, "\n");
 239                 return;
 240         }
 241
 242         trace_seq_printf(s, "%12llu ", cpu_data->irq_count);
 243         trace_seq_printf(s, "%12llu ", cpu_data->softirq_count);
 244         trace_seq_printf(s, "%12llu\n", cpu_data->thread_count);
 245 }
 246
 247 /*
 248  * osnoise_print_stats - print data for all cpus
 249  */
 250 static void
 251 osnoise_print_stats(struct osnoise_top_params *params, struct osnoise_tool *top)
 252 {
 253         struct trace_instance *trace = &top->trace;
 254         static int nr_cpus = -1;
 255         int i;
 256
 257         if (nr_cpus == -1)
 258                 nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 259
 260         if (!params->quiet)
 261                 clear_terminal(trace->seq);
 262
 263         osnoise_top_header(top);
 264
 265         for (i = 0; i < nr_cpus; i++) {
 266                 if (params->cpus && !CPU_ISSET(i, &params->monitored_cpus))
 267                         continue;
 268                 osnoise_top_print(top, i);
 269         }
 270
 271         trace_seq_do_printf(trace->seq);
 272         trace_seq_reset(trace->seq);
 273 }
 274
 275 /*
 276  * osnoise_top_usage - prints osnoise top usage message
 277  */
 278 static void osnoise_top_usage(struct osnoise_top_params *params, char *usage)
 279 {
 280         int i;
 281
 282         static const char * const msg[] = {
 283                 " [-h] [-q] [-D] [-d s] [-a us] [-p us] [-r us] [-s us] [-S us] \\",
 284                 "         [-T us] [-t[=file]] [-e sys[:event]] [--filter <filter>] [--trigger <trigger>] \\",
 285                 "         [-c cpu-list] [-H cpu-list] [-P priority] [-C[=cgroup_name]]",
 286                 "",
 287                 "         -h/--help: print this menu",
 288                 "         -a/--auto: set automatic trace mode, stopping the session if argument in us sample is hit",
 289                 "         -p/--period us: osnoise period in us",
 290                 "         -r/--runtime us: osnoise runtime in us",
 291                 "         -s/--stop us: stop trace if a single sample is higher than the argument in us",
 292                 "         -S/--stop-total us: stop trace if the total sample is higher than the argument in us",
 293                 "         -T/--threshold us: the minimum delta to be considered a noise",
 294                 "         -c/--cpus cpu-list: list of cpus to run osnoise threads",
 295                 "         -H/--house-keeping cpus: run rtla control threads only on the given cpus",
 296                 "         -C/--cgroup[=cgroup_name]: set cgroup, if no cgroup_name is passed, the rtla's cgroup will be inherited",
 297                 "         -d/--duration time[s|m|h|d]: duration of the session",
 298                 "         -D/--debug: print debug info",
 299                 "         -t/--trace[=file]: save the stopped trace to [file|osnoise_trace.txt]",
 300                 "         -e/--event <sys:event>: enable the <sys:event> in the trace instance, multiple -e are allowed",
 301                 "            --filter <filter>: enable a trace event filter to the previous -e event",
 302                 "            --trigger <trigger>: enable a trace event trigger to the previous -e event",
 303                 "         -q/--quiet print only a summary at the end",
 304                 "         -P/--priority o:prio|r:prio|f:prio|d:runtime:period : set scheduling parameters",
 305                 "               o:prio - use SCHED_OTHER with prio",
 306                 "               r:prio - use SCHED_RR with prio",
 307                 "               f:prio - use SCHED_FIFO with prio",
 308                 "               d:runtime[us|ms|s]:period[us|ms|s] - use SCHED_DEADLINE with runtime and period",
 309                 "                                                      in nanoseconds",
 310                 NULL,
 311         };
 312
 313         if (usage)
 314                 fprintf(stderr, "%s\n", usage);
 315
 316         if (params->mode == MODE_OSNOISE) {
 317                 fprintf(stderr,
 318                         "rtla osnoise top: a per-cpu summary of the OS noise (version %s)\n",
 319                         VERSION);
 320
 321                 fprintf(stderr, "  usage: rtla osnoise [top]");
 322         }
 323
 324         if (params->mode == MODE_HWNOISE) {
 325                 fprintf(stderr,
 326                         "rtla hwnoise: a summary of hardware-related noise (version %s)\n",
 327                         VERSION);
 328
 329                 fprintf(stderr, "  usage: rtla hwnoise");
 330         }
 331
 332         for (i = 0; msg[i]; i++)
 333                 fprintf(stderr, "%s\n", msg[i]);
 334
 335         if (usage)
 336                 exit(EXIT_FAILURE);
 337
 338         exit(EXIT_SUCCESS);
 339 }
 340
 341 /*
 342  * osnoise_top_parse_args - allocs, parse and fill the cmd line parameters
 343  */
 344 struct osnoise_top_params *osnoise_top_parse_args(int argc, char **argv)
 345 {
 346         struct osnoise_top_params *params;
 347         struct trace_events *tevent;
 348         int retval;
 349         int c;
 350
 351         params = calloc(1, sizeof(*params));
 352         if (!params)
 353                 exit(1);
 354
 355         if (strcmp(argv[0], "hwnoise") == 0) {
 356                 params->mode = MODE_HWNOISE;
 357                 /*
 358                  * Reduce CPU usage for 75% to avoid killing the system.
 359                  */
 360                 params->runtime = 750000;
 361                 params->period = 1000000;
 362         }
 363
 364         while (1) {
 365                 static struct option long_options[] = {
 366                         {"auto",                required_argument,      0, 'a'},
 367                         {"cpus",                required_argument,      0, 'c'},
 368                         {"cgroup",              optional_argument,      0, 'C'},
 369                         {"debug",               no_argument,            0, 'D'},
 370                         {"duration",            required_argument,      0, 'd'},
 371                         {"event",               required_argument,      0, 'e'},
 372                         {"house-keeping",       required_argument,      0, 'H'},
 373                         {"help",                no_argument,            0, 'h'},
 374                         {"period",              required_argument,      0, 'p'},
 375                         {"priority",            required_argument,      0, 'P'},
 376                         {"quiet",               no_argument,            0, 'q'},
 377                         {"runtime",             required_argument,      0, 'r'},
 378                         {"stop",                required_argument,      0, 's'},
 379                         {"stop-total",          required_argument,      0, 'S'},
 380                         {"threshold",           required_argument,      0, 'T'},
 381                         {"trace",               optional_argument,      0, 't'},
 382                         {"trigger",             required_argument,      0, '0'},
 383                         {"filter",              required_argument,      0, '1'},
 384                         {0, 0, 0, 0}
 385                 };
 386
 387                 /* getopt_long stores the option index here. */
 388                 int option_index = 0;
 389
 390                 c = getopt_long(argc, argv, "a:c:C::d:De:hH:p:P:qr:s:S:t::T:0:1:",
 391                                  long_options, &option_index);
 392
 393                 /* Detect the end of the options. */
 394                 if (c == -1)
 395                         break;
 396
 397                 switch (c) {
 398                 case 'a':
 399                         /* set sample stop to auto_thresh */
 400                         params->stop_us = get_llong_from_str(optarg);
 401
 402                         /* set sample threshold to 1 */
 403                         params->threshold = 1;
 404
 405                         /* set trace */
 406                         params->trace_output = "osnoise_trace.txt";
 407
 408                         break;
 409                 case 'c':
 410                         retval = parse_cpu_set(optarg, &params->monitored_cpus);
 411                         if (retval)
 412                                 osnoise_top_usage(params, "\nInvalid -c cpu list\n");
 413                         params->cpus = optarg;
 414                         break;
 415                 case 'C':
 416                         params->cgroup = 1;
 417                         if (!optarg) {
 418                                 /* will inherit this cgroup */
 419                                 params->cgroup_name = NULL;
 420                         } else if (*optarg == '=') {
 421                                 /* skip the = */
 422                                 params->cgroup_name = ++optarg;
 423                         }
 424                         break;
 425                 case 'D':
 426                         config_debug = 1;
 427                         break;
 428                 case 'd':
 429                         params->duration = parse_seconds_duration(optarg);
 430                         if (!params->duration)
 431                                 osnoise_top_usage(params, "Invalid -D duration\n");
 432                         break;
 433                 case 'e':
 434                         tevent = trace_event_alloc(optarg);
 435                         if (!tevent) {
 436                                 err_msg("Error alloc trace event");
 437                                 exit(EXIT_FAILURE);
 438                         }
 439
 440                         if (params->events)
 441                                 tevent->next = params->events;
 442                         params->events = tevent;
 443
 444                         break;
 445                 case 'h':
 446                 case '?':
 447                         osnoise_top_usage(params, NULL);
 448                         break;
 449                 case 'H':
 450                         params->hk_cpus = 1;
 451                         retval = parse_cpu_set(optarg, &params->hk_cpu_set);
 452                         if (retval) {
 453                                 err_msg("Error parsing house keeping CPUs\n");
 454                                 exit(EXIT_FAILURE);
 455                         }
 456                         break;
 457                 case 'p':
 458                         params->period = get_llong_from_str(optarg);
 459                         if (params->period > 10000000)
 460                                 osnoise_top_usage(params, "Period longer than 10 s\n");
 461                         break;
 462                 case 'P':
 463                         retval = parse_prio(optarg, &params->sched_param);
 464                         if (retval == -1)
 465                                 osnoise_top_usage(params, "Invalid -P priority");
 466                         params->set_sched = 1;
 467                         break;
 468                 case 'q':
 469                         params->quiet = 1;
 470                         break;
 471                 case 'r':
 472                         params->runtime = get_llong_from_str(optarg);
 473                         if (params->runtime < 100)
 474                                 osnoise_top_usage(params, "Runtime shorter than 100 us\n");
 475                         break;
 476                 case 's':
 477                         params->stop_us = get_llong_from_str(optarg);
 478                         break;
 479                 case 'S':
 480                         params->stop_total_us = get_llong_from_str(optarg);
 481                         break;
 482                 case 't':
 483                         if (optarg)
 484                                 /* skip = */
 485                                 params->trace_output = &optarg[1];
 486                         else
 487                                 params->trace_output = "osnoise_trace.txt";
 488                         break;
 489                 case 'T':
 490                         params->threshold = get_llong_from_str(optarg);
 491                         break;
 492                 case '0': /* trigger */
 493                         if (params->events) {
 494                                 retval = trace_event_add_trigger(params->events, optarg);
 495                                 if (retval) {
 496                                         err_msg("Error adding trigger %s\n", optarg);
 497                                         exit(EXIT_FAILURE);
 498                                 }
 499                         } else {
 500                                 osnoise_top_usage(params, "--trigger requires a previous -e\n");
 501                         }
 502                         break;
 503                 case '1': /* filter */
 504                         if (params->events) {
 505                                 retval = trace_event_add_filter(params->events, optarg);
 506                                 if (retval) {
 507                                         err_msg("Error adding filter %s\n", optarg);
 508                                         exit(EXIT_FAILURE);
 509                                 }
 510                         } else {
 511                                 osnoise_top_usage(params, "--filter requires a previous -e\n");
 512                         }
 513                         break;
 514                 default:
 515                         osnoise_top_usage(params, "Invalid option");
 516                 }
 517         }
 518
 519         if (geteuid()) {
 520                 err_msg("osnoise needs root permission\n");
 521                 exit(EXIT_FAILURE);
 522         }
 523
 524         return params;
 525 }
 526
 527 /*
 528  * osnoise_top_apply_config - apply the top configs to the initialized tool
 529  */
 530 static int
 531 osnoise_top_apply_config(struct osnoise_tool *tool, struct osnoise_top_params *params)
 532 {
 533         int retval;
 534
 535         if (!params->sleep_time)
 536                 params->sleep_time = 1;
 537
 538         if (params->cpus) {
 539                 retval = osnoise_set_cpus(tool->context, params->cpus);
 540                 if (retval) {
 541                         err_msg("Failed to apply CPUs config\n");
 542                         goto out_err;
 543                 }
 544         }
 545
 546         if (params->runtime || params->period) {
 547                 retval = osnoise_set_runtime_period(tool->context,
 548                                                     params->runtime,
 549                                                     params->period);
 550                 if (retval) {
 551                         err_msg("Failed to set runtime and/or period\n");
 552                         goto out_err;
 553                 }
 554         }
 555
 556         if (params->stop_us) {
 557                 retval = osnoise_set_stop_us(tool->context, params->stop_us);
 558                 if (retval) {
 559                         err_msg("Failed to set stop us\n");
 560                         goto out_err;
 561                 }
 562         }
 563
 564         if (params->stop_total_us) {
 565                 retval = osnoise_set_stop_total_us(tool->context, params->stop_total_us);
 566                 if (retval) {
 567                         err_msg("Failed to set stop total us\n");
 568                         goto out_err;
 569                 }
 570         }
 571
 572         if (params->threshold) {
 573                 retval = osnoise_set_tracing_thresh(tool->context, params->threshold);
 574                 if (retval) {
 575                         err_msg("Failed to set tracing_thresh\n");
 576                         goto out_err;
 577                 }
 578         }
 579
 580         if (params->mode == MODE_HWNOISE) {
 581                 retval = osnoise_set_irq_disable(tool->context, 1);
 582                 if (retval) {
 583                         err_msg("Failed to set OSNOISE_IRQ_DISABLE option\n");
 584                         goto out_err;
 585                 }
 586         }
 587
 588         if (params->hk_cpus) {
 589                 retval = sched_setaffinity(getpid(), sizeof(params->hk_cpu_set),
 590                                            &params->hk_cpu_set);
 591                 if (retval == -1) {
 592                         err_msg("Failed to set rtla to the house keeping CPUs\n");
 593                         goto out_err;
 594                 }
 595         } else if (params->cpus) {
 596                 /*
 597                  * Even if the user do not set a house-keeping CPU, try to
 598                  * move rtla to a CPU set different to the one where the user
 599                  * set the workload to run.
 600                  *
 601                  * No need to check results as this is an automatic attempt.
 602                  */
 603                 auto_house_keeping(&params->monitored_cpus);
 604         }
 605
 606         return 0;
 607
 608 out_err:
 609         return -1;
 610 }
 611
 612 /*
 613  * osnoise_init_top - initialize a osnoise top tool with parameters
 614  */
 615 struct osnoise_tool *osnoise_init_top(struct osnoise_top_params *params)
 616 {
 617         struct osnoise_tool *tool;
 618         int nr_cpus;
 619
 620         nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
 621
 622         tool = osnoise_init_tool("osnoise_top");
 623         if (!tool)
 624                 return NULL;
 625
 626         tool->data = osnoise_alloc_top(nr_cpus);
 627         if (!tool->data)
 628                 goto out_err;
 629
 630         tool->params = params;
 631
 632         tep_register_event_handler(tool->trace.tep, -1, "ftrace", "osnoise",
 633                                    osnoise_top_handler, NULL);
 634
 635         return tool;
 636
 637 out_err:
 638         osnoise_free_top(tool->data);
 639         osnoise_destroy_tool(tool);
 640         return NULL;
 641 }
 642
 643 static int stop_tracing;
 644 static void stop_top(int sig)
 645 {
 646         stop_tracing = 1;
 647 }
 648
 649 /*
 650  * osnoise_top_set_signals - handles the signal to stop the tool
 651  */
 652 static void osnoise_top_set_signals(struct osnoise_top_params *params)
 653 {
 654         signal(SIGINT, stop_top);
 655         if (params->duration) {
 656                 signal(SIGALRM, stop_top);
 657                 alarm(params->duration);
 658         }
 659 }
 660
 661 int osnoise_top_main(int argc, char **argv)
 662 {
 663         struct osnoise_top_params *params;
 664         struct osnoise_tool *record = NULL;
 665         struct osnoise_tool *tool = NULL;
 666         struct trace_instance *trace;
 667         int return_value = 1;
 668         int retval;
 669
 670         params = osnoise_top_parse_args(argc, argv);
 671         if (!params)
 672                 exit(1);
 673
 674         tool = osnoise_init_top(params);
 675         if (!tool) {
 676                 err_msg("Could not init osnoise top\n");
 677                 goto out_exit;
 678         }
 679
 680         retval = osnoise_top_apply_config(tool, params);
 681         if (retval) {
 682                 err_msg("Could not apply config\n");
 683                 goto out_free;
 684         }
 685
 686         trace = &tool->trace;
 687
 688         retval = enable_osnoise(trace);
 689         if (retval) {
 690                 err_msg("Failed to enable osnoise tracer\n");
 691                 goto out_free;
 692         }
 693
 694         if (params->set_sched) {
 695                 retval = set_comm_sched_attr("osnoise/", &params->sched_param);
 696                 if (retval) {
 697                         err_msg("Failed to set sched parameters\n");
 698                         goto out_free;
 699                 }
 700         }
 701
 702         if (params->cgroup) {
 703                 retval = set_comm_cgroup("osnoise/", params->cgroup_name);
 704                 if (!retval) {
 705                         err_msg("Failed to move threads to cgroup\n");
 706                         goto out_free;
 707                 }
 708         }
 709
 710         if (params->trace_output) {
 711                 record = osnoise_init_trace_tool("osnoise");
 712                 if (!record) {
 713                         err_msg("Failed to enable the trace instance\n");
 714                         goto out_free;
 715                 }
 716
 717                 if (params->events) {
 718                         retval = trace_events_enable(&record->trace, params->events);
 719                         if (retval)
 720                                 goto out_top;
 721                 }
 722         }
 723
 724         /*
 725          * Start the tracer here, after having set all instances.
 726          *
 727          * Let the trace instance start first for the case of hitting a stop
 728          * tracing while enabling other instances. The trace instance is the
 729          * one with most valuable information.
 730          */
 731         if (params->trace_output)
 732                 trace_instance_start(&record->trace);
 733         trace_instance_start(trace);
 734
 735         tool->start_time = time(NULL);
 736         osnoise_top_set_signals(params);
 737
 738         while (!stop_tracing) {
 739                 sleep(params->sleep_time);
 740
 741                 retval = tracefs_iterate_raw_events(trace->tep,
 742                                                     trace->inst,
 743                                                     NULL,
 744                                                     0,
 745                                                     collect_registered_events,
 746                                                     trace);
 747                 if (retval < 0) {
 748                         err_msg("Error iterating on events\n");
 749                         goto out_top;
 750                 }
 751
 752                 if (!params->quiet)
 753                         osnoise_print_stats(params, tool);
 754
 755                 if (trace_is_off(&tool->trace, &record->trace))
 756                         break;
 757
 758         }
 759
 760         osnoise_print_stats(params, tool);
 761
 762         return_value = 0;
 763
 764         if (trace_is_off(&tool->trace, &record->trace)) {
 765                 printf("osnoise hit stop tracing\n");
 766                 if (params->trace_output) {
 767                         printf("  Saving trace to %s\n", params->trace_output);
 768                         save_trace_to_file(record->trace.inst, params->trace_output);
 769                 }
 770         }
 771
 772 out_top:
 773         trace_events_destroy(&record->trace, params->events);
 774         params->events = NULL;
 775 out_free:
 776         osnoise_free_top(tool->data);
 777         osnoise_destroy_tool(record);
 778         osnoise_destroy_tool(tool);
 779         free(params);
 780 out_exit:
 781         exit(return_value);
 782 }