tools/perf/builtin-annotate.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * builtin-annotate.c
   4  *
   5  * Builtin annotate command: Analyze the perf.data input file,
   6  * look up and read DSOs and symbol information and display
   7  * a histogram of results, along various sorting keys.
   8  */
   9 #include "builtin.h"
  10
  11 #include "util/color.h"
  12 #include <linux/list.h>
  13 #include "util/cache.h"
  14 #include <linux/rbtree.h>
  15 #include <linux/zalloc.h>
  16 #include "util/symbol.h"
  17
  18 #include "perf.h"
  19 #include "util/debug.h"
  20
  21 #include "util/evlist.h"
  22 #include "util/evsel.h"
  23 #include "util/annotate.h"
  24 #include "util/event.h"
  25 #include <subcmd/parse-options.h>
  26 #include "util/parse-events.h"
  27 #include "util/sort.h"
  28 #include "util/hist.h"
  29 #include "util/dso.h"
  30 #include "util/machine.h"
  31 #include "util/map.h"
  32 #include "util/session.h"
  33 #include "util/tool.h"
  34 #include "util/data.h"
  35 #include "arch/common.h"
  36 #include "util/block-range.h"
  37 #include "util/map_symbol.h"
  38 #include "util/branch.h"
  39
  40 #include <dlfcn.h>
  41 #include <errno.h>
  42 #include <linux/bitmap.h>
  43 #include <linux/err.h>
  44
  45 struct perf_annotate {
  46         struct perf_tool tool;
  47         struct perf_session *session;
  48         struct annotation_options opts;
  49 #ifdef HAVE_SLANG_SUPPORT
  50         bool       use_tui;
  51 #endif
  52         bool       use_stdio, use_stdio2;
  53         bool       use_gtk;
  54         bool       skip_missing;
  55         bool       has_br_stack;
  56         bool       group_set;
  57         const char *sym_hist_filter;
  58         const char *cpu_list;
  59         DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
  60 };
  61
  62 /*
  63  * Given one basic block:
  64  *
  65  *      from    to              branch_i
  66  *      * ----> *
  67  *              |
  68  *              | block
  69  *              v
  70  *              * ----> *
  71  *              from    to      branch_i+1
  72  *
  73  * where the horizontal are the branches and the vertical is the executed
  74  * block of instructions.
  75  *
  76  * We count, for each 'instruction', the number of blocks that covered it as
  77  * well as count the ratio each branch is taken.
  78  *
  79  * We can do this without knowing the actual instruction stream by keeping
  80  * track of the address ranges. We break down ranges such that there is no
  81  * overlap and iterate from the start until the end.
  82  *
  83  * @acme: once we parse the objdump output _before_ processing the samples,
  84  * we can easily fold the branch.cycles IPC bits in.
  85  */
  86 static void process_basic_block(struct addr_map_symbol *start,
  87                                 struct addr_map_symbol *end,
  88                                 struct branch_flags *flags)
  89 {
  90         struct symbol *sym = start->ms.sym;
  91         struct annotation *notes = sym ? symbol__annotation(sym) : NULL;
  92         struct block_range_iter iter;
  93         struct block_range *entry;
  94
  95         /*
  96          * Sanity; NULL isn't executable and the CPU cannot execute backwards
  97          */
  98         if (!start->addr || start->addr > end->addr)
  99                 return;
 100
 101         iter = block_range__create(start->addr, end->addr);
 102         if (!block_range_iter__valid(&iter))
 103                 return;
 104
 105         /*
 106          * First block in range is a branch target.
 107          */
 108         entry = block_range_iter(&iter);
 109         assert(entry->is_target);
 110         entry->entry++;
 111
 112         do {
 113                 entry = block_range_iter(&iter);
 114
 115                 entry->coverage++;
 116                 entry->sym = sym;
 117
 118                 if (notes)
 119                         notes->max_coverage = max(notes->max_coverage, entry->coverage);
 120
 121         } while (block_range_iter__next(&iter));
 122
 123         /*
 124          * Last block in rage is a branch.
 125          */
 126         entry = block_range_iter(&iter);
 127         assert(entry->is_branch);
 128         entry->taken++;
 129         if (flags->predicted)
 130                 entry->pred++;
 131 }
 132
 133 static void process_branch_stack(struct branch_stack *bs, struct addr_location *al,
 134                                  struct perf_sample *sample)
 135 {
 136         struct addr_map_symbol *prev = NULL;
 137         struct branch_info *bi;
 138         int i;
 139
 140         if (!bs || !bs->nr)
 141                 return;
 142
 143         bi = sample__resolve_bstack(sample, al);
 144         if (!bi)
 145                 return;
 146
 147         for (i = bs->nr - 1; i >= 0; i--) {
 148                 /*
 149                  * XXX filter against symbol
 150                  */
 151                 if (prev)
 152                         process_basic_block(prev, &bi[i].from, &bi[i].flags);
 153                 prev = &bi[i].to;
 154         }
 155
 156         free(bi);
 157 }
 158
 159 static int hist_iter__branch_callback(struct hist_entry_iter *iter,
 160                                       struct addr_location *al __maybe_unused,
 161                                       bool single __maybe_unused,
 162                                       void *arg __maybe_unused)
 163 {
 164         struct hist_entry *he = iter->he;
 165         struct branch_info *bi;
 166         struct perf_sample *sample = iter->sample;
 167         struct evsel *evsel = iter->evsel;
 168         int err;
 169
 170         bi = he->branch_info;
 171         err = addr_map_symbol__inc_samples(&bi->from, sample, evsel);
 172
 173         if (err)
 174                 goto out;
 175
 176         err = addr_map_symbol__inc_samples(&bi->to, sample, evsel);
 177
 178 out:
 179         return err;
 180 }
 181
 182 static int process_branch_callback(struct evsel *evsel,
 183                                    struct perf_sample *sample,
 184                                    struct addr_location *al __maybe_unused,
 185                                    struct perf_annotate *ann,
 186                                    struct machine *machine)
 187 {
 188         struct hist_entry_iter iter = {
 189                 .evsel          = evsel,
 190                 .sample         = sample,
 191                 .add_entry_cb   = hist_iter__branch_callback,
 192                 .hide_unresolved        = symbol_conf.hide_unresolved,
 193                 .ops            = &hist_iter_branch,
 194         };
 195
 196         struct addr_location a;
 197
 198         if (machine__resolve(machine, &a, sample) < 0)
 199                 return -1;
 200
 201         if (a.sym == NULL)
 202                 return 0;
 203
 204         if (a.map != NULL)
 205                 a.map->dso->hit = 1;
 206
 207         hist__account_cycles(sample->branch_stack, al, sample, false, NULL);
 208
 209         return hist_entry_iter__add(&iter, &a, PERF_MAX_STACK_DEPTH, ann);
 210 }
 211
 212 static bool has_annotation(struct perf_annotate *ann)
 213 {
 214         return ui__has_annotation() || ann->use_stdio2;
 215 }
 216
 217 static int evsel__add_sample(struct evsel *evsel, struct perf_sample *sample,
 218                              struct addr_location *al, struct perf_annotate *ann,
 219                              struct machine *machine)
 220 {
 221         struct hists *hists = evsel__hists(evsel);
 222         struct hist_entry *he;
 223         int ret;
 224
 225         if ((!ann->has_br_stack || !has_annotation(ann)) &&
 226             ann->sym_hist_filter != NULL &&
 227             (al->sym == NULL ||
 228              strcmp(ann->sym_hist_filter, al->sym->name) != 0)) {
 229                 /* We're only interested in a symbol named sym_hist_filter */
 230                 /*
 231                  * FIXME: why isn't this done in the symbol_filter when loading
 232                  * the DSO?
 233                  */
 234                 if (al->sym != NULL) {
 235                         rb_erase_cached(&al->sym->rb_node,
 236                                  &al->map->dso->symbols);
 237                         symbol__delete(al->sym);
 238                         dso__reset_find_symbol_cache(al->map->dso);
 239                 }
 240                 return 0;
 241         }
 242
 243         /*
 244          * XXX filtered samples can still have branch entries pointing into our
 245          * symbol and are missed.
 246          */
 247         process_branch_stack(sample->branch_stack, al, sample);
 248
 249         if (ann->has_br_stack && has_annotation(ann))
 250                 return process_branch_callback(evsel, sample, al, ann, machine);
 251
 252         he = hists__add_entry(hists, al, NULL, NULL, NULL, sample, true);
 253         if (he == NULL)
 254                 return -ENOMEM;
 255
 256         ret = hist_entry__inc_addr_samples(he, sample, evsel, al->addr);
 257         hists__inc_nr_samples(hists, true);
 258         return ret;
 259 }
 260
 261 static int process_sample_event(struct perf_tool *tool,
 262                                 union perf_event *event,
 263                                 struct perf_sample *sample,
 264                                 struct evsel *evsel,
 265                                 struct machine *machine)
 266 {
 267         struct perf_annotate *ann = container_of(tool, struct perf_annotate, tool);
 268         struct addr_location al;
 269         int ret = 0;
 270
 271         if (machine__resolve(machine, &al, sample) < 0) {
 272                 pr_warning("problem processing %d event, skipping it.\n",
 273                            event->header.type);
 274                 return -1;
 275         }
 276
 277         if (ann->cpu_list && !test_bit(sample->cpu, ann->cpu_bitmap))
 278                 goto out_put;
 279
 280         if (!al.filtered &&
 281             evsel__add_sample(evsel, sample, &al, ann, machine)) {
 282                 pr_warning("problem incrementing symbol count, "
 283                            "skipping event\n");
 284                 ret = -1;
 285         }
 286 out_put:
 287         addr_location__put(&al);
 288         return ret;
 289 }
 290
 291 static int process_feature_event(struct perf_session *session,
 292                                  union perf_event *event)
 293 {
 294         if (event->feat.feat_id < HEADER_LAST_FEATURE)
 295                 return perf_event__process_feature(session, event);
 296         return 0;
 297 }
 298
 299 static int hist_entry__tty_annotate(struct hist_entry *he,
 300                                     struct evsel *evsel,
 301                                     struct perf_annotate *ann)
 302 {
 303         if (!ann->use_stdio2)
 304                 return symbol__tty_annotate(&he->ms, evsel, &ann->opts);
 305
 306         return symbol__tty_annotate2(&he->ms, evsel, &ann->opts);
 307 }
 308
 309 static void hists__find_annotations(struct hists *hists,
 310                                     struct evsel *evsel,
 311                                     struct perf_annotate *ann)
 312 {
 313         struct rb_node *nd = rb_first_cached(&hists->entries), *next;
 314         int key = K_RIGHT;
 315
 316         while (nd) {
 317                 struct hist_entry *he = rb_entry(nd, struct hist_entry, rb_node);
 318                 struct annotation *notes;
 319
 320                 if (he->ms.sym == NULL || he->ms.map->dso->annotate_warned)
 321                         goto find_next;
 322
 323                 if (ann->sym_hist_filter &&
 324                     (strcmp(he->ms.sym->name, ann->sym_hist_filter) != 0))
 325                         goto find_next;
 326
 327                 notes = symbol__annotation(he->ms.sym);
 328                 if (notes->src == NULL) {
 329 find_next:
 330                         if (key == K_LEFT)
 331                                 nd = rb_prev(nd);
 332                         else
 333                                 nd = rb_next(nd);
 334                         continue;
 335                 }
 336
 337                 if (use_browser == 2) {
 338                         int ret;
 339                         int (*annotate)(struct hist_entry *he,
 340                                         struct evsel *evsel,
 341                                         struct hist_browser_timer *hbt);
 342
 343                         annotate = dlsym(perf_gtk_handle,
 344                                          "hist_entry__gtk_annotate");
 345                         if (annotate == NULL) {
 346                                 ui__error("GTK browser not found!\n");
 347                                 return;
 348                         }
 349
 350                         ret = annotate(he, evsel, NULL);
 351                         if (!ret || !ann->skip_missing)
 352                                 return;
 353
 354                         /* skip missing symbols */
 355                         nd = rb_next(nd);
 356                 } else if (use_browser == 1) {
 357                         key = hist_entry__tui_annotate(he, evsel, NULL, &ann->opts);
 358
 359                         switch (key) {
 360                         case -1:
 361                                 if (!ann->skip_missing)
 362                                         return;
 363                                 /* fall through */
 364                         case K_RIGHT:
 365                                 next = rb_next(nd);
 366                                 break;
 367                         case K_LEFT:
 368                                 next = rb_prev(nd);
 369                                 break;
 370                         default:
 371                                 return;
 372                         }
 373
 374                         if (next != NULL)
 375                                 nd = next;
 376                 } else {
 377                         hist_entry__tty_annotate(he, evsel, ann);
 378                         nd = rb_next(nd);
 379                 }
 380         }
 381 }
 382
 383 static int __cmd_annotate(struct perf_annotate *ann)
 384 {
 385         int ret;
 386         struct perf_session *session = ann->session;
 387         struct evsel *pos;
 388         u64 total_nr_samples;
 389
 390         if (ann->cpu_list) {
 391                 ret = perf_session__cpu_bitmap(session, ann->cpu_list,
 392                                                ann->cpu_bitmap);
 393                 if (ret)
 394                         goto out;
 395         }
 396
 397         if (!ann->opts.objdump_path) {
 398                 ret = perf_env__lookup_objdump(&session->header.env,
 399                                                &ann->opts.objdump_path);
 400                 if (ret)
 401                         goto out;
 402         }
 403
 404         ret = perf_session__process_events(session);
 405         if (ret)
 406                 goto out;
 407
 408         if (dump_trace) {
 409                 perf_session__fprintf_nr_events(session, stdout, false);
 410                 evlist__fprintf_nr_events(session->evlist, stdout, false);
 411                 goto out;
 412         }
 413
 414         if (verbose > 3)
 415                 perf_session__fprintf(session, stdout);
 416
 417         if (verbose > 2)
 418                 perf_session__fprintf_dsos(session, stdout);
 419
 420         total_nr_samples = 0;
 421         evlist__for_each_entry(session->evlist, pos) {
 422                 struct hists *hists = evsel__hists(pos);
 423                 u32 nr_samples = hists->stats.nr_samples;
 424
 425                 if (nr_samples > 0) {
 426                         total_nr_samples += nr_samples;
 427                         hists__collapse_resort(hists, NULL);
 428                         /* Don't sort callchain */
 429                         evsel__reset_sample_bit(pos, CALLCHAIN);
 430                         evsel__output_resort(pos, NULL);
 431
 432                         if (symbol_conf.event_group && !evsel__is_group_leader(pos))
 433                                 continue;
 434
 435                         hists__find_annotations(hists, pos, ann);
 436                 }
 437         }
 438
 439         if (total_nr_samples == 0) {
 440                 ui__error("The %s data has no samples!\n", session->data->path);
 441                 goto out;
 442         }
 443
 444         if (use_browser == 2) {
 445                 void (*show_annotations)(void);
 446
 447                 show_annotations = dlsym(perf_gtk_handle,
 448                                          "perf_gtk__show_annotations");
 449                 if (show_annotations == NULL) {
 450                         ui__error("GTK browser not found!\n");
 451                         goto out;
 452                 }
 453                 show_annotations();
 454         }
 455
 456 out:
 457         return ret;
 458 }
 459
 460 static const char * const annotate_usage[] = {
 461         "perf annotate [<options>]",
 462         NULL
 463 };
 464
 465 int cmd_annotate(int argc, const char **argv)
 466 {
 467         struct perf_annotate annotate = {
 468                 .tool = {
 469                         .sample = process_sample_event,
 470                         .mmap   = perf_event__process_mmap,
 471                         .mmap2  = perf_event__process_mmap2,
 472                         .comm   = perf_event__process_comm,
 473                         .exit   = perf_event__process_exit,
 474                         .fork   = perf_event__process_fork,
 475                         .namespaces = perf_event__process_namespaces,
 476                         .attr   = perf_event__process_attr,
 477                         .build_id = perf_event__process_build_id,
 478                         .tracing_data   = perf_event__process_tracing_data,
 479                         .id_index       = perf_event__process_id_index,
 480                         .auxtrace_info  = perf_event__process_auxtrace_info,
 481                         .auxtrace       = perf_event__process_auxtrace,
 482                         .feature        = process_feature_event,
 483                         .ordered_events = true,
 484                         .ordering_requires_timestamps = true,
 485                 },
 486                 .opts = annotation__default_options,
 487         };
 488         struct perf_data data = {
 489                 .mode  = PERF_DATA_MODE_READ,
 490         };
 491         struct itrace_synth_opts itrace_synth_opts = {
 492                 .set = 0,
 493         };
 494         struct option options[] = {
 495         OPT_STRING('i', "input", &input_name, "file",
 496                     "input file name"),
 497         OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
 498                    "only consider symbols in these dsos"),
 499         OPT_STRING('s', "symbol", &annotate.sym_hist_filter, "symbol",
 500                     "symbol to annotate"),
 501         OPT_BOOLEAN('f', "force", &data.force, "don't complain, do it"),
 502         OPT_INCR('v', "verbose", &verbose,
 503                     "be more verbose (show symbol address, etc)"),
 504         OPT_BOOLEAN('q', "quiet", &quiet, "do now show any message"),
 505         OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
 506                     "dump raw trace in ASCII"),
 507         OPT_BOOLEAN(0, "gtk", &annotate.use_gtk, "Use the GTK interface"),
 508 #ifdef HAVE_SLANG_SUPPORT
 509         OPT_BOOLEAN(0, "tui", &annotate.use_tui, "Use the TUI interface"),
 510 #endif
 511         OPT_BOOLEAN(0, "stdio", &annotate.use_stdio, "Use the stdio interface"),
 512         OPT_BOOLEAN(0, "stdio2", &annotate.use_stdio2, "Use the stdio interface"),
 513         OPT_BOOLEAN(0, "ignore-vmlinux", &symbol_conf.ignore_vmlinux,
 514                     "don't load vmlinux even if found"),
 515         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 516                    "file", "vmlinux pathname"),
 517         OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
 518                     "load module symbols - WARNING: use only with -k and LIVE kernel"),
 519         OPT_BOOLEAN('l', "print-line", &annotate.opts.print_lines,
 520                     "print matching source lines (may be slow)"),
 521         OPT_BOOLEAN('P', "full-paths", &annotate.opts.full_path,
 522                     "Don't shorten the displayed pathnames"),
 523         OPT_BOOLEAN(0, "skip-missing", &annotate.skip_missing,
 524                     "Skip symbols that cannot be annotated"),
 525         OPT_BOOLEAN_SET(0, "group", &symbol_conf.event_group,
 526                         &annotate.group_set,
 527                         "Show event group information together"),
 528         OPT_STRING('C', "cpu", &annotate.cpu_list, "cpu", "list of cpus to profile"),
 529         OPT_CALLBACK(0, "symfs", NULL, "directory",
 530                      "Look for files with symbols relative to this directory",
 531                      symbol__config_symfs),
 532         OPT_BOOLEAN(0, "source", &annotate.opts.annotate_src,
 533                     "Interleave source code with assembly code (default)"),
 534         OPT_BOOLEAN(0, "asm-raw", &annotate.opts.show_asm_raw,
 535                     "Display raw encoding of assembly instructions (default)"),
 536         OPT_STRING('M', "disassembler-style", &annotate.opts.disassembler_style, "disassembler style",
 537                    "Specify disassembler style (e.g. -M intel for intel syntax)"),
 538         OPT_STRING(0, "prefix", &annotate.opts.prefix, "prefix",
 539                     "Add prefix to source file path names in programs (with --prefix-strip)"),
 540         OPT_STRING(0, "prefix-strip", &annotate.opts.prefix_strip, "N",
 541                     "Strip first N entries of source file path name in programs (with --prefix)"),
 542         OPT_STRING(0, "objdump", &annotate.opts.objdump_path, "path",
 543                    "objdump binary to use for disassembly and annotations"),
 544         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 545                     "Enable symbol demangling"),
 546         OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 547                     "Enable kernel symbol demangling"),
 548         OPT_BOOLEAN(0, "group", &symbol_conf.event_group,
 549                     "Show event group information together"),
 550         OPT_BOOLEAN(0, "show-total-period", &symbol_conf.show_total_period,
 551                     "Show a column with the sum of periods"),
 552         OPT_BOOLEAN('n', "show-nr-samples", &symbol_conf.show_nr_samples,
 553                     "Show a column with the number of samples"),
 554         OPT_CALLBACK_DEFAULT(0, "stdio-color", NULL, "mode",
 555                              "'always' (default), 'never' or 'auto' only applicable to --stdio mode",
 556                              stdio__config_color, "always"),
 557         OPT_CALLBACK(0, "percent-type", &annotate.opts, "local-period",
 558                      "Set percent type local/global-period/hits",
 559                      annotate_parse_percent_type),
 560         OPT_CALLBACK_OPTARG(0, "itrace", &itrace_synth_opts, NULL, "opts",
 561                             "Instruction Tracing options\n" ITRACE_HELP,
 562                             itrace_parse_synth_opts),
 563
 564         OPT_END()
 565         };
 566         int ret;
 567
 568         set_option_flag(options, 0, "show-total-period", PARSE_OPT_EXCLUSIVE);
 569         set_option_flag(options, 0, "show-nr-samples", PARSE_OPT_EXCLUSIVE);
 570
 571
 572         ret = hists__init();
 573         if (ret < 0)
 574                 return ret;
 575
 576         annotation_config__init(&annotate.opts);
 577
 578         argc = parse_options(argc, argv, options, annotate_usage, 0);
 579         if (argc) {
 580                 /*
 581                  * Special case: if there's an argument left then assume that
 582                  * it's a symbol filter:
 583                  */
 584                 if (argc > 1)
 585                         usage_with_options(annotate_usage, options);
 586
 587                 annotate.sym_hist_filter = argv[0];
 588         }
 589
 590         if (annotate_check_args(&annotate.opts) < 0)
 591                 return -EINVAL;
 592
 593         if (symbol_conf.show_nr_samples && annotate.use_gtk) {
 594                 pr_err("--show-nr-samples is not available in --gtk mode at this time\n");
 595                 return ret;
 596         }
 597
 598         ret = symbol__validate_sym_arguments();
 599         if (ret)
 600                 return ret;
 601
 602         if (quiet)
 603                 perf_quiet_option();
 604
 605         data.path = input_name;
 606
 607         annotate.session = perf_session__new(&data, &annotate.tool);
 608         if (IS_ERR(annotate.session))
 609                 return PTR_ERR(annotate.session);
 610
 611         annotate.session->itrace_synth_opts = &itrace_synth_opts;
 612
 613         annotate.has_br_stack = perf_header__has_feat(&annotate.session->header,
 614                                                       HEADER_BRANCH_STACK);
 615
 616         if (annotate.group_set)
 617                 evlist__force_leader(annotate.session->evlist);
 618
 619         ret = symbol__annotation_init();
 620         if (ret < 0)
 621                 goto out_delete;
 622
 623         symbol_conf.try_vmlinux_path = true;
 624
 625         ret = symbol__init(&annotate.session->header.env);
 626         if (ret < 0)
 627                 goto out_delete;
 628
 629         if (annotate.use_stdio || annotate.use_stdio2)
 630                 use_browser = 0;
 631 #ifdef HAVE_SLANG_SUPPORT
 632         else if (annotate.use_tui)
 633                 use_browser = 1;
 634 #endif
 635         else if (annotate.use_gtk)
 636                 use_browser = 2;
 637
 638         setup_browser(true);
 639
 640         /*
 641          * Events of different processes may correspond to the same
 642          * symbol, we do not care about the processes in annotate,
 643          * set sort order to avoid repeated output.
 644          */
 645         sort_order = "dso,symbol";
 646
 647         /*
 648          * Set SORT_MODE__BRANCH so that annotate display IPC/Cycle
 649          * if branch info is in perf data in TUI mode.
 650          */
 651         if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack)
 652                 sort__mode = SORT_MODE__BRANCH;
 653
 654         if (setup_sorting(NULL) < 0)
 655                 usage_with_options(annotate_usage, options);
 656
 657         ret = __cmd_annotate(&annotate);
 658
 659 out_delete:
 660         /*
 661          * Speed up the exit process, for large files this can
 662          * take quite a while.
 663          *
 664          * XXX Enable this when using valgrind or if we ever
 665          * librarize this command.
 666          *
 667          * Also experiment with obstacks to see how much speed
 668          * up we'll get here.
 669          *
 670          * perf_session__delete(session);
 671          */
 672         return ret;
 673 }