tools/perf/builtin-kmem.c

   1 #include "builtin.h"
   2 #include "perf.h"
   3
   4 #include "util/evlist.h"
   5 #include "util/evsel.h"
   6 #include "util/util.h"
   7 #include "util/cache.h"
   8 #include "util/symbol.h"
   9 #include "util/thread.h"
  10 #include "util/header.h"
  11 #include "util/session.h"
  12 #include "util/tool.h"
  13
  14 #include "util/parse-options.h"
  15 #include "util/trace-event.h"
  16 #include "util/data.h"
  17 #include "util/cpumap.h"
  18
  19 #include "util/debug.h"
  20
  21 #include <linux/rbtree.h>
  22 #include <linux/string.h>
  23
  24 struct alloc_stat;
  25 typedef int (*sort_fn_t)(struct alloc_stat *, struct alloc_stat *);
  26
  27 static int                      alloc_flag;
  28 static int                      caller_flag;
  29
  30 static int                      alloc_lines = -1;
  31 static int                      caller_lines = -1;
  32
  33 static bool                     raw_ip;
  34
  35 struct alloc_stat {
  36         u64     call_site;
  37         u64     ptr;
  38         u64     bytes_req;
  39         u64     bytes_alloc;
  40         u32     hit;
  41         u32     pingpong;
  42
  43         short   alloc_cpu;
  44
  45         struct rb_node node;
  46 };
  47
  48 static struct rb_root root_alloc_stat;
  49 static struct rb_root root_alloc_sorted;
  50 static struct rb_root root_caller_stat;
  51 static struct rb_root root_caller_sorted;
  52
  53 static unsigned long total_requested, total_allocated;
  54 static unsigned long nr_allocs, nr_cross_allocs;
  55
  56 static int insert_alloc_stat(unsigned long call_site, unsigned long ptr,
  57                              int bytes_req, int bytes_alloc, int cpu)
  58 {
  59         struct rb_node **node = &root_alloc_stat.rb_node;
  60         struct rb_node *parent = NULL;
  61         struct alloc_stat *data = NULL;
  62
  63         while (*node) {
  64                 parent = *node;
  65                 data = rb_entry(*node, struct alloc_stat, node);
  66
  67                 if (ptr > data->ptr)
  68                         node = &(*node)->rb_right;
  69                 else if (ptr < data->ptr)
  70                         node = &(*node)->rb_left;
  71                 else
  72                         break;
  73         }
  74
  75         if (data && data->ptr == ptr) {
  76                 data->hit++;
  77                 data->bytes_req += bytes_req;
  78                 data->bytes_alloc += bytes_alloc;
  79         } else {
  80                 data = malloc(sizeof(*data));
  81                 if (!data) {
  82                         pr_err("%s: malloc failed\n", __func__);
  83                         return -1;
  84                 }
  85                 data->ptr = ptr;
  86                 data->pingpong = 0;
  87                 data->hit = 1;
  88                 data->bytes_req = bytes_req;
  89                 data->bytes_alloc = bytes_alloc;
  90
  91                 rb_link_node(&data->node, parent, node);
  92                 rb_insert_color(&data->node, &root_alloc_stat);
  93         }
  94         data->call_site = call_site;
  95         data->alloc_cpu = cpu;
  96         return 0;
  97 }
  98
  99 static int insert_caller_stat(unsigned long call_site,
 100                               int bytes_req, int bytes_alloc)
 101 {
 102         struct rb_node **node = &root_caller_stat.rb_node;
 103         struct rb_node *parent = NULL;
 104         struct alloc_stat *data = NULL;
 105
 106         while (*node) {
 107                 parent = *node;
 108                 data = rb_entry(*node, struct alloc_stat, node);
 109
 110                 if (call_site > data->call_site)
 111                         node = &(*node)->rb_right;
 112                 else if (call_site < data->call_site)
 113                         node = &(*node)->rb_left;
 114                 else
 115                         break;
 116         }
 117
 118         if (data && data->call_site == call_site) {
 119                 data->hit++;
 120                 data->bytes_req += bytes_req;
 121                 data->bytes_alloc += bytes_alloc;
 122         } else {
 123                 data = malloc(sizeof(*data));
 124                 if (!data) {
 125                         pr_err("%s: malloc failed\n", __func__);
 126                         return -1;
 127                 }
 128                 data->call_site = call_site;
 129                 data->pingpong = 0;
 130                 data->hit = 1;
 131                 data->bytes_req = bytes_req;
 132                 data->bytes_alloc = bytes_alloc;
 133
 134                 rb_link_node(&data->node, parent, node);
 135                 rb_insert_color(&data->node, &root_caller_stat);
 136         }
 137
 138         return 0;
 139 }
 140
 141 static int perf_evsel__process_alloc_event(struct perf_evsel *evsel,
 142                                            struct perf_sample *sample)
 143 {
 144         unsigned long ptr = perf_evsel__intval(evsel, sample, "ptr"),
 145                       call_site = perf_evsel__intval(evsel, sample, "call_site");
 146         int bytes_req = perf_evsel__intval(evsel, sample, "bytes_req"),
 147             bytes_alloc = perf_evsel__intval(evsel, sample, "bytes_alloc");
 148
 149         if (insert_alloc_stat(call_site, ptr, bytes_req, bytes_alloc, sample->cpu) ||
 150             insert_caller_stat(call_site, bytes_req, bytes_alloc))
 151                 return -1;
 152
 153         total_requested += bytes_req;
 154         total_allocated += bytes_alloc;
 155
 156         nr_allocs++;
 157         return 0;
 158 }
 159
 160 static int perf_evsel__process_alloc_node_event(struct perf_evsel *evsel,
 161                                                 struct perf_sample *sample)
 162 {
 163         int ret = perf_evsel__process_alloc_event(evsel, sample);
 164
 165         if (!ret) {
 166                 int node1 = cpu__get_node(sample->cpu),
 167                     node2 = perf_evsel__intval(evsel, sample, "node");
 168
 169                 if (node1 != node2)
 170                         nr_cross_allocs++;
 171         }
 172
 173         return ret;
 174 }
 175
 176 static int ptr_cmp(struct alloc_stat *, struct alloc_stat *);
 177 static int callsite_cmp(struct alloc_stat *, struct alloc_stat *);
 178
 179 static struct alloc_stat *search_alloc_stat(unsigned long ptr,
 180                                             unsigned long call_site,
 181                                             struct rb_root *root,
 182                                             sort_fn_t sort_fn)
 183 {
 184         struct rb_node *node = root->rb_node;
 185         struct alloc_stat key = { .ptr = ptr, .call_site = call_site };
 186
 187         while (node) {
 188                 struct alloc_stat *data;
 189                 int cmp;
 190
 191                 data = rb_entry(node, struct alloc_stat, node);
 192
 193                 cmp = sort_fn(&key, data);
 194                 if (cmp < 0)
 195                         node = node->rb_left;
 196                 else if (cmp > 0)
 197                         node = node->rb_right;
 198                 else
 199                         return data;
 200         }
 201         return NULL;
 202 }
 203
 204 static int perf_evsel__process_free_event(struct perf_evsel *evsel,
 205                                           struct perf_sample *sample)
 206 {
 207         unsigned long ptr = perf_evsel__intval(evsel, sample, "ptr");
 208         struct alloc_stat *s_alloc, *s_caller;
 209
 210         s_alloc = search_alloc_stat(ptr, 0, &root_alloc_stat, ptr_cmp);
 211         if (!s_alloc)
 212                 return 0;
 213
 214         if ((short)sample->cpu != s_alloc->alloc_cpu) {
 215                 s_alloc->pingpong++;
 216
 217                 s_caller = search_alloc_stat(0, s_alloc->call_site,
 218                                              &root_caller_stat, callsite_cmp);
 219                 if (!s_caller)
 220                         return -1;
 221                 s_caller->pingpong++;
 222         }
 223         s_alloc->alloc_cpu = -1;
 224
 225         return 0;
 226 }
 227
 228 typedef int (*tracepoint_handler)(struct perf_evsel *evsel,
 229                                   struct perf_sample *sample);
 230
 231 static int process_sample_event(struct perf_tool *tool __maybe_unused,
 232                                 union perf_event *event,
 233                                 struct perf_sample *sample,
 234                                 struct perf_evsel *evsel,
 235                                 struct machine *machine)
 236 {
 237         struct thread *thread = machine__findnew_thread(machine, sample->pid,
 238                                                         sample->tid);
 239
 240         if (thread == NULL) {
 241                 pr_debug("problem processing %d event, skipping it.\n",
 242                          event->header.type);
 243                 return -1;
 244         }
 245
 246         dump_printf(" ... thread: %s:%d\n", thread__comm_str(thread), thread->tid);
 247
 248         if (evsel->handler != NULL) {
 249                 tracepoint_handler f = evsel->handler;
 250                 return f(evsel, sample);
 251         }
 252
 253         return 0;
 254 }
 255
 256 static struct perf_tool perf_kmem = {
 257         .sample          = process_sample_event,
 258         .comm            = perf_event__process_comm,
 259         .ordered_samples = true,
 260 };
 261
 262 static double fragmentation(unsigned long n_req, unsigned long n_alloc)
 263 {
 264         if (n_alloc == 0)
 265                 return 0.0;
 266         else
 267                 return 100.0 - (100.0 * n_req / n_alloc);
 268 }
 269
 270 static void __print_result(struct rb_root *root, struct perf_session *session,
 271                            int n_lines, int is_caller)
 272 {
 273         struct rb_node *next;
 274         struct machine *machine = &session->machines.host;
 275
 276         printf("%.102s\n", graph_dotted_line);
 277         printf(" %-34s |",  is_caller ? "Callsite": "Alloc Ptr");
 278         printf(" Total_alloc/Per | Total_req/Per   | Hit      | Ping-pong | Frag\n");
 279         printf("%.102s\n", graph_dotted_line);
 280
 281         next = rb_first(root);
 282
 283         while (next && n_lines--) {
 284                 struct alloc_stat *data = rb_entry(next, struct alloc_stat,
 285                                                    node);
 286                 struct symbol *sym = NULL;
 287                 struct map *map;
 288                 char buf[BUFSIZ];
 289                 u64 addr;
 290
 291                 if (is_caller) {
 292                         addr = data->call_site;
 293                         if (!raw_ip)
 294                                 sym = machine__find_kernel_function(machine, addr, &map, NULL);
 295                 } else
 296                         addr = data->ptr;
 297
 298                 if (sym != NULL)
 299                         snprintf(buf, sizeof(buf), "%s+%" PRIx64 "", sym->name,
 300                                  addr - map->unmap_ip(map, sym->start));
 301                 else
 302                         snprintf(buf, sizeof(buf), "%#" PRIx64 "", addr);
 303                 printf(" %-34s |", buf);
 304
 305                 printf(" %9llu/%-5lu | %9llu/%-5lu | %8lu | %8lu | %6.3f%%\n",
 306                        (unsigned long long)data->bytes_alloc,
 307                        (unsigned long)data->bytes_alloc / data->hit,
 308                        (unsigned long long)data->bytes_req,
 309                        (unsigned long)data->bytes_req / data->hit,
 310                        (unsigned long)data->hit,
 311                        (unsigned long)data->pingpong,
 312                        fragmentation(data->bytes_req, data->bytes_alloc));
 313
 314                 next = rb_next(next);
 315         }
 316
 317         if (n_lines == -1)
 318                 printf(" ...                                | ...             | ...             | ...    | ...      | ...   \n");
 319
 320         printf("%.102s\n", graph_dotted_line);
 321 }
 322
 323 static void print_summary(void)
 324 {
 325         printf("\nSUMMARY\n=======\n");
 326         printf("Total bytes requested: %lu\n", total_requested);
 327         printf("Total bytes allocated: %lu\n", total_allocated);
 328         printf("Total bytes wasted on internal fragmentation: %lu\n",
 329                total_allocated - total_requested);
 330         printf("Internal fragmentation: %f%%\n",
 331                fragmentation(total_requested, total_allocated));
 332         printf("Cross CPU allocations: %lu/%lu\n", nr_cross_allocs, nr_allocs);
 333 }
 334
 335 static void print_result(struct perf_session *session)
 336 {
 337         if (caller_flag)
 338                 __print_result(&root_caller_sorted, session, caller_lines, 1);
 339         if (alloc_flag)
 340                 __print_result(&root_alloc_sorted, session, alloc_lines, 0);
 341         print_summary();
 342 }
 343
 344 struct sort_dimension {
 345         const char              name[20];
 346         sort_fn_t               cmp;
 347         struct list_head        list;
 348 };
 349
 350 static LIST_HEAD(caller_sort);
 351 static LIST_HEAD(alloc_sort);
 352
 353 static void sort_insert(struct rb_root *root, struct alloc_stat *data,
 354                         struct list_head *sort_list)
 355 {
 356         struct rb_node **new = &(root->rb_node);
 357         struct rb_node *parent = NULL;
 358         struct sort_dimension *sort;
 359
 360         while (*new) {
 361                 struct alloc_stat *this;
 362                 int cmp = 0;
 363
 364                 this = rb_entry(*new, struct alloc_stat, node);
 365                 parent = *new;
 366
 367                 list_for_each_entry(sort, sort_list, list) {
 368                         cmp = sort->cmp(data, this);
 369                         if (cmp)
 370                                 break;
 371                 }
 372
 373                 if (cmp > 0)
 374                         new = &((*new)->rb_left);
 375                 else
 376                         new = &((*new)->rb_right);
 377         }
 378
 379         rb_link_node(&data->node, parent, new);
 380         rb_insert_color(&data->node, root);
 381 }
 382
 383 static void __sort_result(struct rb_root *root, struct rb_root *root_sorted,
 384                           struct list_head *sort_list)
 385 {
 386         struct rb_node *node;
 387         struct alloc_stat *data;
 388
 389         for (;;) {
 390                 node = rb_first(root);
 391                 if (!node)
 392                         break;
 393
 394                 rb_erase(node, root);
 395                 data = rb_entry(node, struct alloc_stat, node);
 396                 sort_insert(root_sorted, data, sort_list);
 397         }
 398 }
 399
 400 static void sort_result(void)
 401 {
 402         __sort_result(&root_alloc_stat, &root_alloc_sorted, &alloc_sort);
 403         __sort_result(&root_caller_stat, &root_caller_sorted, &caller_sort);
 404 }
 405
 406 static int __cmd_kmem(void)
 407 {
 408         int err = -EINVAL;
 409         struct perf_session *session;
 410         const struct perf_evsel_str_handler kmem_tracepoints[] = {
 411                 { "kmem:kmalloc",               perf_evsel__process_alloc_event, },
 412                 { "kmem:kmem_cache_alloc",      perf_evsel__process_alloc_event, },
 413                 { "kmem:kmalloc_node",          perf_evsel__process_alloc_node_event, },
 414                 { "kmem:kmem_cache_alloc_node", perf_evsel__process_alloc_node_event, },
 415                 { "kmem:kfree",                 perf_evsel__process_free_event, },
 416                 { "kmem:kmem_cache_free",       perf_evsel__process_free_event, },
 417         };
 418         struct perf_data_file file = {
 419                 .path = input_name,
 420                 .mode = PERF_DATA_MODE_READ,
 421         };
 422
 423         session = perf_session__new(&file, false, &perf_kmem);
 424         if (session == NULL)
 425                 return -ENOMEM;
 426
 427         if (perf_session__create_kernel_maps(session) < 0)
 428                 goto out_delete;
 429
 430         if (!perf_session__has_traces(session, "kmem record"))
 431                 goto out_delete;
 432
 433         if (perf_session__set_tracepoints_handlers(session, kmem_tracepoints)) {
 434                 pr_err("Initializing perf session tracepoint handlers failed\n");
 435                 return -1;
 436         }
 437
 438         setup_pager();
 439         err = perf_session__process_events(session, &perf_kmem);
 440         if (err != 0)
 441                 goto out_delete;
 442         sort_result();
 443         print_result(session);
 444 out_delete:
 445         perf_session__delete(session);
 446         return err;
 447 }
 448
 449 static int ptr_cmp(struct alloc_stat *l, struct alloc_stat *r)
 450 {
 451         if (l->ptr < r->ptr)
 452                 return -1;
 453         else if (l->ptr > r->ptr)
 454                 return 1;
 455         return 0;
 456 }
 457
 458 static struct sort_dimension ptr_sort_dimension = {
 459         .name   = "ptr",
 460         .cmp    = ptr_cmp,
 461 };
 462
 463 static int callsite_cmp(struct alloc_stat *l, struct alloc_stat *r)
 464 {
 465         if (l->call_site < r->call_site)
 466                 return -1;
 467         else if (l->call_site > r->call_site)
 468                 return 1;
 469         return 0;
 470 }
 471
 472 static struct sort_dimension callsite_sort_dimension = {
 473         .name   = "callsite",
 474         .cmp    = callsite_cmp,
 475 };
 476
 477 static int hit_cmp(struct alloc_stat *l, struct alloc_stat *r)
 478 {
 479         if (l->hit < r->hit)
 480                 return -1;
 481         else if (l->hit > r->hit)
 482                 return 1;
 483         return 0;
 484 }
 485
 486 static struct sort_dimension hit_sort_dimension = {
 487         .name   = "hit",
 488         .cmp    = hit_cmp,
 489 };
 490
 491 static int bytes_cmp(struct alloc_stat *l, struct alloc_stat *r)
 492 {
 493         if (l->bytes_alloc < r->bytes_alloc)
 494                 return -1;
 495         else if (l->bytes_alloc > r->bytes_alloc)
 496                 return 1;
 497         return 0;
 498 }
 499
 500 static struct sort_dimension bytes_sort_dimension = {
 501         .name   = "bytes",
 502         .cmp    = bytes_cmp,
 503 };
 504
 505 static int frag_cmp(struct alloc_stat *l, struct alloc_stat *r)
 506 {
 507         double x, y;
 508
 509         x = fragmentation(l->bytes_req, l->bytes_alloc);
 510         y = fragmentation(r->bytes_req, r->bytes_alloc);
 511
 512         if (x < y)
 513                 return -1;
 514         else if (x > y)
 515                 return 1;
 516         return 0;
 517 }
 518
 519 static struct sort_dimension frag_sort_dimension = {
 520         .name   = "frag",
 521         .cmp    = frag_cmp,
 522 };
 523
 524 static int pingpong_cmp(struct alloc_stat *l, struct alloc_stat *r)
 525 {
 526         if (l->pingpong < r->pingpong)
 527                 return -1;
 528         else if (l->pingpong > r->pingpong)
 529                 return 1;
 530         return 0;
 531 }
 532
 533 static struct sort_dimension pingpong_sort_dimension = {
 534         .name   = "pingpong",
 535         .cmp    = pingpong_cmp,
 536 };
 537
 538 static struct sort_dimension *avail_sorts[] = {
 539         &ptr_sort_dimension,
 540         &callsite_sort_dimension,
 541         &hit_sort_dimension,
 542         &bytes_sort_dimension,
 543         &frag_sort_dimension,
 544         &pingpong_sort_dimension,
 545 };
 546
 547 #define NUM_AVAIL_SORTS ((int)ARRAY_SIZE(avail_sorts))
 548
 549 static int sort_dimension__add(const char *tok, struct list_head *list)
 550 {
 551         struct sort_dimension *sort;
 552         int i;
 553
 554         for (i = 0; i < NUM_AVAIL_SORTS; i++) {
 555                 if (!strcmp(avail_sorts[i]->name, tok)) {
 556                         sort = memdup(avail_sorts[i], sizeof(*avail_sorts[i]));
 557                         if (!sort) {
 558                                 pr_err("%s: memdup failed\n", __func__);
 559                                 return -1;
 560                         }
 561                         list_add_tail(&sort->list, list);
 562                         return 0;
 563                 }
 564         }
 565
 566         return -1;
 567 }
 568
 569 static int setup_sorting(struct list_head *sort_list, const char *arg)
 570 {
 571         char *tok;
 572         char *str = strdup(arg);
 573
 574         if (!str) {
 575                 pr_err("%s: strdup failed\n", __func__);
 576                 return -1;
 577         }
 578
 579         while (true) {
 580                 tok = strsep(&str, ",");
 581                 if (!tok)
 582                         break;
 583                 if (sort_dimension__add(tok, sort_list) < 0) {
 584                         error("Unknown --sort key: '%s'", tok);
 585                         free(str);
 586                         return -1;
 587                 }
 588         }
 589
 590         free(str);
 591         return 0;
 592 }
 593
 594 static int parse_sort_opt(const struct option *opt __maybe_unused,
 595                           const char *arg, int unset __maybe_unused)
 596 {
 597         if (!arg)
 598                 return -1;
 599
 600         if (caller_flag > alloc_flag)
 601                 return setup_sorting(&caller_sort, arg);
 602         else
 603                 return setup_sorting(&alloc_sort, arg);
 604
 605         return 0;
 606 }
 607
 608 static int parse_caller_opt(const struct option *opt __maybe_unused,
 609                             const char *arg __maybe_unused,
 610                             int unset __maybe_unused)
 611 {
 612         caller_flag = (alloc_flag + 1);
 613         return 0;
 614 }
 615
 616 static int parse_alloc_opt(const struct option *opt __maybe_unused,
 617                            const char *arg __maybe_unused,
 618                            int unset __maybe_unused)
 619 {
 620         alloc_flag = (caller_flag + 1);
 621         return 0;
 622 }
 623
 624 static int parse_line_opt(const struct option *opt __maybe_unused,
 625                           const char *arg, int unset __maybe_unused)
 626 {
 627         int lines;
 628
 629         if (!arg)
 630                 return -1;
 631
 632         lines = strtoul(arg, NULL, 10);
 633
 634         if (caller_flag > alloc_flag)
 635                 caller_lines = lines;
 636         else
 637                 alloc_lines = lines;
 638
 639         return 0;
 640 }
 641
 642 static int __cmd_record(int argc, const char **argv)
 643 {
 644         const char * const record_args[] = {
 645         "record", "-a", "-R", "-c", "1",
 646         "-e", "kmem:kmalloc",
 647         "-e", "kmem:kmalloc_node",
 648         "-e", "kmem:kfree",
 649         "-e", "kmem:kmem_cache_alloc",
 650         "-e", "kmem:kmem_cache_alloc_node",
 651         "-e", "kmem:kmem_cache_free",
 652         };
 653         unsigned int rec_argc, i, j;
 654         const char **rec_argv;
 655
 656         rec_argc = ARRAY_SIZE(record_args) + argc - 1;
 657         rec_argv = calloc(rec_argc + 1, sizeof(char *));
 658
 659         if (rec_argv == NULL)
 660                 return -ENOMEM;
 661
 662         for (i = 0; i < ARRAY_SIZE(record_args); i++)
 663                 rec_argv[i] = strdup(record_args[i]);
 664
 665         for (j = 1; j < (unsigned int)argc; j++, i++)
 666                 rec_argv[i] = argv[j];
 667
 668         return cmd_record(i, rec_argv, NULL);
 669 }
 670
 671 int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
 672 {
 673         const char * const default_sort_order = "frag,hit,bytes";
 674         const struct option kmem_options[] = {
 675         OPT_STRING('i', "input", &input_name, "file", "input file name"),
 676         OPT_CALLBACK_NOOPT(0, "caller", NULL, NULL,
 677                            "show per-callsite statistics", parse_caller_opt),
 678         OPT_CALLBACK_NOOPT(0, "alloc", NULL, NULL,
 679                            "show per-allocation statistics", parse_alloc_opt),
 680         OPT_CALLBACK('s', "sort", NULL, "key[,key2...]",
 681                      "sort by keys: ptr, call_site, bytes, hit, pingpong, frag",
 682                      parse_sort_opt),
 683         OPT_CALLBACK('l', "line", NULL, "num", "show n lines", parse_line_opt),
 684         OPT_BOOLEAN(0, "raw-ip", &raw_ip, "show raw ip instead of symbol"),
 685         OPT_END()
 686         };
 687         const char *const kmem_subcommands[] = { "record", "stat", NULL };
 688         const char *kmem_usage[] = {
 689                 NULL,
 690                 NULL
 691         };
 692         argc = parse_options_subcommand(argc, argv, kmem_options,
 693                                         kmem_subcommands, kmem_usage, 0);
 694
 695         if (!argc)
 696                 usage_with_options(kmem_usage, kmem_options);
 697
 698         symbol__init();
 699
 700         if (!strncmp(argv[0], "rec", 3)) {
 701                 return __cmd_record(argc, argv);
 702         } else if (!strcmp(argv[0], "stat")) {
 703                 if (cpu__setup_cpunode_map())
 704                         return -1;
 705
 706                 if (list_empty(&caller_sort))
 707                         setup_sorting(&caller_sort, default_sort_order);
 708                 if (list_empty(&alloc_sort))
 709                         setup_sorting(&alloc_sort, default_sort_order);
 710
 711                 return __cmd_kmem();
 712         } else
 713                 usage_with_options(kmem_usage, kmem_options);
 714
 715         return 0;
 716 }
 717