blktrace.c

   1 /*
   2  * block queue tracing application
   3  *
   4  * Copyright (C) 2005 Jens Axboe <axboe@suse.de>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21 #include <pthread.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <unistd.h>
  25 #include <locale.h>
  26 #include <signal.h>
  27 #include <fcntl.h>
  28 #include <string.h>
  29 #include <sys/ioctl.h>
  30 #include <sys/param.h>
  31 #include <sys/statfs.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <sched.h>
  35 #include <ctype.h>
  36 #include <getopt.h>
  37 #include <sys/mman.h>
  38
  39 #include "blktrace.h"
  40
  41 #define BUF_SIZE        (128 *1024)
  42 #define BUF_NR          (4)
  43
  44 #define RELAYFS_TYPE    0xF0B4A981
  45
  46 #define DECLARE_MASK_MAP(mask)          { BLK_TC_##mask, #mask, "BLK_TC_"#mask }
  47 #define COMPARE_MASK_MAP(mmp, str)                                      \
  48         (!strcasecmp((mmp)->short_form, (str)) ||                      \
  49          !strcasecmp((mmp)->long_form, (str)))
  50
  51 #define VALID_SET(x)    ((1 <= (x)) && ((x) < (1 << BLK_TC_SHIFT)))
  52
  53 struct mask_map {
  54         int mask;
  55         char *short_form;
  56         char *long_form;
  57 };
  58
  59 struct mask_map mask_maps[] = {
  60         DECLARE_MASK_MAP(READ),
  61         DECLARE_MASK_MAP(WRITE),
  62         DECLARE_MASK_MAP(BARRIER),
  63         DECLARE_MASK_MAP(SYNC),
  64         DECLARE_MASK_MAP(QUEUE),
  65         DECLARE_MASK_MAP(REQUEUE),
  66         DECLARE_MASK_MAP(ISSUE),
  67         DECLARE_MASK_MAP(COMPLETE),
  68         DECLARE_MASK_MAP(FS),
  69         DECLARE_MASK_MAP(PC),
  70 };
  71
  72 #define S_OPTS  "d:a:A:r:o:kw:"
  73 static struct option l_opts[] = {
  74         {
  75                 .name = "dev",
  76                 .has_arg = 1,
  77                 .flag = NULL,
  78                 .val = 'd'
  79         },
  80         {
  81                 .name = "act-mask",
  82                 .has_arg = 1,
  83                 .flag = NULL,
  84                 .val = 'a'
  85         },
  86         {
  87                 .name = "set-mask",
  88                 .has_arg = 1,
  89                 .flag = NULL,
  90                 .val = 'A'
  91         },
  92         {
  93                 .name = "relay",
  94                 .has_arg = 1,
  95                 .flag = NULL,
  96                 .val = 'r'
  97         },
  98         {
  99                 .name = "output",
 100                 .has_arg = 1,
 101                 .flag = NULL,
 102                 .val = 'o'
 103         },
 104         {
 105                 .name = "kill",
 106                 .has_arg = 0,
 107                 .flag = NULL,
 108                 .val = 'k'
 109         },
 110         {
 111                 .name = "stopwatch",
 112                 .has_arg = 1,
 113                 .flag = NULL,
 114                 .val = 'w'
 115         },
 116         {
 117                 .name = NULL,
 118                 .has_arg = 0,
 119                 .flag = NULL,
 120                 .val = 0
 121         }
 122 };
 123
 124 struct thread_information {
 125         int cpu;
 126         pthread_t thread;
 127
 128         int fd;
 129         char fn[MAXPATHLEN + 64];
 130         void *buf;
 131         unsigned long buf_offset;
 132         unsigned int buf_subbuf;
 133         unsigned int sequence;
 134
 135         pthread_mutex_t *fd_lock;
 136         int ofd;
 137
 138         unsigned long events_processed;
 139         struct device_information *device;
 140 };
 141
 142 struct device_information {
 143         int fd;
 144         char *path;
 145         char buts_name[32];
 146         int trace_started;
 147         struct thread_information *threads;
 148 };
 149
 150 static int ncpus;
 151 static struct thread_information *thread_information;
 152 static int ndevs;
 153 static struct device_information *device_information;
 154
 155 /* command line option globals */
 156 static char *relay_path;
 157 static char *output_name;
 158 static int act_mask = ~0U;
 159 static int kill_running_trace;
 160 static int use_mmap;
 161
 162 #define is_done()       (*(volatile int *)(&done))
 163 static volatile int done;
 164
 165 static pthread_mutex_t stdout_mutex = PTHREAD_MUTEX_INITIALIZER;
 166
 167 static void exit_trace(int status);
 168
 169 static int find_mask_map(char *string)
 170 {
 171         int i;
 172
 173         for (i = 0; i < sizeof(mask_maps)/sizeof(mask_maps[0]); i++)
 174                 if (COMPARE_MASK_MAP(&mask_maps[i], string))
 175                         return mask_maps[i].mask;
 176
 177         return -1;
 178 }
 179
 180 static int start_trace(struct device_information *dip)
 181 {
 182         struct blk_user_trace_setup buts;
 183
 184         memset(&buts, 0, sizeof(buts));
 185         buts.buf_size = BUF_SIZE;
 186         buts.buf_nr = BUF_NR;
 187         buts.act_mask = act_mask;
 188
 189         if (ioctl(dip->fd, BLKSTARTTRACE, &buts) < 0) {
 190                 perror("BLKSTARTTRACE");
 191                 return 1;
 192         }
 193
 194         memcpy(dip->buts_name, buts.name, sizeof(dip->buts_name));
 195         dip->trace_started = 1;
 196         return 0;
 197 }
 198
 199 static void stop_trace(struct device_information *dip)
 200 {
 201         if (dip->trace_started || kill_running_trace) {
 202                 if (ioctl(dip->fd, BLKSTOPTRACE) < 0)
 203                         perror("BLKSTOPTRACE");
 204                 close(dip->fd);
 205                 dip->trace_started = 0;
 206         }
 207 }
 208
 209 static void stop_all_traces(void)
 210 {
 211         struct device_information *dip;
 212         int i;
 213
 214         for (dip = device_information, i = 0; i < ndevs; i++, dip++)
 215                 stop_trace(dip);
 216 }
 217
 218 static int get_data_read(struct thread_information *tip, void *buf, int len)
 219 {
 220         char *p = buf;
 221         int ret, bytes_left = len;
 222
 223         while (!is_done() && bytes_left > 0) {
 224                 ret = read(tip->fd, p, bytes_left);
 225                 if (ret == len)
 226                         break;
 227
 228                 if (ret < 0) {
 229                         perror(tip->fn);
 230                         fprintf(stderr,"Thread %d failed read of %s\n",
 231                                 tip->cpu, tip->fn);
 232                         exit_trace(1);
 233                 } else if (ret > 0) {
 234                         fprintf(stderr,"Thread %d misread %s %d,%d\n",
 235                                 tip->cpu, tip->fn, ret, len);
 236                         exit_trace(1);
 237                 } else {
 238                         p += ret;
 239                         bytes_left -= ret;
 240                 }
 241
 242                 usleep(10000);
 243         }
 244
 245         return 0;
 246 }
 247
 248 static int get_data_mmap(struct thread_information *tip, void *buf, int len,
 249                          int check_magic)
 250 {
 251         if (len > (BUF_SIZE * (tip->buf_subbuf + 1)) - tip->buf_offset) {
 252                 tip->buf_subbuf++;
 253                 if (tip->buf_subbuf == BUF_NR)
 254                         tip->buf_subbuf = 0;
 255
 256                 tip->buf_offset = tip->buf_subbuf * BUF_SIZE;
 257         }
 258
 259         while (!is_done()) {
 260                 struct blk_io_trace *t = buf;
 261
 262                 memcpy(buf, tip->buf + tip->buf_offset, len);
 263
 264                 if (!check_magic)
 265                         break;
 266
 267                 if (CHECK_MAGIC(t) && t->sequence >= tip->sequence) {
 268                         tip->sequence = t->sequence;
 269                         break;
 270                 }
 271
 272                 usleep(10000);
 273         }
 274
 275         tip->buf_offset += len;
 276         return 0;
 277 }
 278
 279 static int get_data(struct thread_information *tip, void *buf, int len,
 280                     int check_magic)
 281 {
 282         if (tip->buf)
 283                 return get_data_mmap(tip, buf, len, check_magic);
 284         else
 285                 return get_data_read(tip, buf, len);
 286 }
 287
 288 static void *extract_data(struct thread_information *tip, char *ofn, int nb)
 289 {
 290         unsigned char *buf;
 291
 292         buf = malloc(nb);
 293         if (!get_data(tip, buf, nb, 0))
 294                 return buf;
 295
 296         free(buf);
 297         exit_trace(1);
 298         return NULL;
 299 }
 300
 301 static inline void tip_fd_unlock(struct thread_information *tip)
 302 {
 303         if (tip->fd_lock)
 304                 pthread_mutex_unlock(tip->fd_lock);
 305 }
 306
 307 static inline void tip_fd_lock(struct thread_information *tip)
 308 {
 309         if (tip->fd_lock)
 310                 pthread_mutex_lock(tip->fd_lock);
 311 }
 312
 313 static void *extract(void *arg)
 314 {
 315         struct thread_information *tip = arg;
 316         int ret, pdu_len;
 317         char dp[64], *pdu_data;
 318         struct blk_io_trace t;
 319         pid_t pid = getpid();
 320         cpu_set_t cpu_mask;
 321
 322         CPU_ZERO(&cpu_mask);
 323         CPU_SET((tip->cpu), &cpu_mask);
 324
 325         if (sched_setaffinity(pid, sizeof(cpu_mask), &cpu_mask) == -1) {
 326                 perror("sched_setaffinity");
 327                 exit_trace(1);
 328         }
 329
 330         snprintf(tip->fn, sizeof(tip->fn), "%s/block/%s/trace%d",
 331                         relay_path, tip->device->buts_name, tip->cpu);
 332         tip->fd = open(tip->fn, O_RDONLY);
 333         if (tip->fd < 0) {
 334                 perror(tip->fn);
 335                 fprintf(stderr,"Thread %d failed open of %s\n", tip->cpu,
 336                         tip->fn);
 337                 exit_trace(1);
 338         }
 339
 340         if (use_mmap) {
 341                 tip->buf = mmap(NULL, BUF_SIZE * BUF_NR, PROT_READ,
 342                                         MAP_PRIVATE | MAP_POPULATE, tip->fd, 0);
 343                 if (tip->buf == MAP_FAILED) {
 344                         perror("mmap");
 345                         exit_trace(1);
 346                 }
 347         }
 348
 349         pdu_data = NULL;
 350         while (!is_done()) {
 351                 if (get_data(tip, &t, sizeof(t), 1))
 352                         break;
 353
 354                 if (verify_trace(&t))
 355                         exit_trace(1);
 356
 357                 pdu_len = t.pdu_len;
 358
 359                 trace_to_be(&t);
 360
 361                 if (pdu_len)
 362                         pdu_data = extract_data(tip, dp, pdu_len);
 363
 364                 /*
 365                  * now we have both trace and payload, get a lock on the
 366                  * output descriptor and send it off
 367                  */
 368                 tip_fd_lock(tip);
 369
 370                 ret = write(tip->ofd, &t, sizeof(t));
 371                 if (ret < 0) {
 372                         fprintf(stderr,"Thread %d failed write\n", tip->cpu);
 373                         tip_fd_unlock(tip);
 374                         exit_trace(1);
 375                 }
 376
 377                 if (pdu_data) {
 378                         ret = write(tip->ofd, pdu_data, pdu_len);
 379                         if (ret != pdu_len) {
 380                                 perror("write pdu data");
 381                                 tip_fd_unlock(tip);
 382                                 exit_trace(1);
 383                         }
 384
 385                         free(pdu_data);
 386                         pdu_data = NULL;
 387                 }
 388
 389                 tip_fd_unlock(tip);
 390                 tip->events_processed++;
 391         }
 392
 393         return NULL;
 394 }
 395
 396 static int start_threads(struct device_information *dip)
 397 {
 398         struct thread_information *tip;
 399         char op[64];
 400         int j, pipeline = output_name && !strcmp(output_name, "-");
 401
 402         for (tip = dip->threads, j = 0; j < ncpus; j++, tip++) {
 403                 tip->cpu = j;
 404                 tip->device = dip;
 405                 tip->fd_lock = NULL;
 406                 tip->events_processed = 0;
 407
 408                 if (pipeline) {
 409                         tip->ofd = dup(STDOUT_FILENO);
 410                         tip->fd_lock = &stdout_mutex;
 411                 } else {
 412                         if (output_name)
 413                                 sprintf(op, "%s_%s_out.%d", output_name,
 414                                         dip->buts_name, tip->cpu);
 415                         else
 416                                 sprintf(op, "%s_out.%d",
 417                                         dip->buts_name, tip->cpu);
 418                         tip->ofd = open(op, O_CREAT|O_TRUNC|O_WRONLY, 0644);
 419                 }
 420
 421                 if (tip->ofd < 0) {
 422                         perror(op);
 423                         return 1;
 424                 }
 425
 426                 if (pthread_create(&tip->thread, NULL, extract, tip)) {
 427                         perror("pthread_create");
 428                         close(tip->ofd);
 429                         return 1;
 430                 }
 431         }
 432
 433         return 0;
 434 }
 435
 436 static void close_thread(struct thread_information *tip)
 437 {
 438         if (tip->buf)
 439                 munmap(tip->buf, BUF_SIZE * BUF_NR);
 440
 441         if (tip->fd != -1)
 442                 close(tip->fd);
 443         if (tip->ofd != -1)
 444                 close(tip->ofd);
 445
 446         tip->fd = tip->ofd = -1;
 447 }
 448
 449 static void stop_threads(struct device_information *dip)
 450 {
 451         struct thread_information *tip;
 452         long ret;
 453         int j;
 454
 455         for (tip = dip->threads, j = 0; j < ncpus; j++, tip++) {
 456                 if (pthread_join(tip->thread, (void *) &ret))
 457                         perror("thread_join");
 458                 close_thread(tip);
 459         }
 460 }
 461
 462 static void stop_all_threads(void)
 463 {
 464         struct device_information *dip;
 465         int i;
 466
 467         for (dip = device_information, i = 0; i < ndevs; i++, dip++)
 468                 stop_threads(dip);
 469 }
 470
 471 static void stop_all_tracing(void)
 472 {
 473         struct device_information *dip;
 474         struct thread_information *tip;
 475         int i, j;
 476
 477         for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
 478                 for (tip = dip->threads, j = 0; j < ncpus; j++, tip++)
 479                         close_thread(tip);
 480                 stop_trace(dip);
 481         }
 482 }
 483
 484 static void exit_trace(int status)
 485 {
 486         stop_all_tracing();
 487         exit(status);
 488 }
 489
 490 static int resize_devices(char *path)
 491 {
 492         int size = (ndevs + 1) * sizeof(struct device_information);
 493
 494         device_information = realloc(device_information, size);
 495         if (!device_information) {
 496                 fprintf(stderr, "Out of memory, device %s (%d)\n", path, size);
 497                 return 1;
 498         }
 499         device_information[ndevs].path = path;
 500         ndevs++;
 501         return 0;
 502 }
 503
 504 static int open_devices(void)
 505 {
 506         struct device_information *dip;
 507         int i;
 508
 509         for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
 510                 dip->fd = open(dip->path, O_RDONLY);
 511                 if (dip->fd < 0) {
 512                         perror(dip->path);
 513                         return 1;
 514                 }
 515         }
 516         return 0;
 517 }
 518
 519 static int start_devices(void)
 520 {
 521         struct device_information *dip;
 522         int i, j, size;
 523
 524         size = ncpus * sizeof(struct thread_information);
 525         thread_information = malloc(size * ndevs);
 526         if (!thread_information) {
 527                 fprintf(stderr, "Out of memory, threads (%d)\n", size * ndevs);
 528                 return 1;
 529         }
 530
 531         for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
 532                 if (start_trace(dip)) {
 533                         close(dip->fd);
 534                         fprintf(stderr, "Failed to start trace on %s\n",
 535                                 dip->path);
 536                         break;
 537                 }
 538         }
 539         if (i != ndevs) {
 540                 for (dip = device_information, j = 0; j < i; j++, dip++)
 541                         stop_trace(dip);
 542                 return 1;
 543         }
 544
 545         for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
 546                 dip->threads = thread_information + (i * ncpus);
 547                 if (start_threads(dip)) {
 548                         fprintf(stderr, "Failed to start worker threads\n");
 549                         break;
 550                 }
 551         }
 552         if (i != ndevs) {
 553                 for (dip = device_information, j = 0; j < i; j++, dip++)
 554                         stop_threads(dip);
 555                 for (dip = device_information, i = 0; i < ndevs; i++, dip++)
 556                         stop_trace(dip);
 557                 return 1;
 558         }
 559
 560         return 0;
 561 }
 562
 563 static void show_stats(void)
 564 {
 565         int i, j;
 566         struct device_information *dip;
 567         struct thread_information *tip;
 568         unsigned long long events_processed;
 569
 570         if (output_name && !strcmp(output_name, "-"))
 571                 return;
 572
 573         for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
 574                 printf("Device: %s\n", dip->path);
 575                 events_processed = 0;
 576                 for (tip = dip->threads, j = 0; j < ncpus; j++, tip++) {
 577                         printf("  CPU%3d: %20ld events\n",
 578                                tip->cpu, tip->events_processed);
 579                         events_processed += tip->events_processed;
 580                 }
 581                 printf("  Total:  %20lld events\n", events_processed);
 582         }
 583 }
 584
 585 static void show_usage(char *program)
 586 {
 587         fprintf(stderr,"Usage: %s [-d <dev>] "
 588                        "[-a <trace> [-a <trace>]] <dev>\n",
 589                 program);
 590 }
 591
 592 static void handle_sigint(int sig)
 593 {
 594         done = 1;
 595 }
 596
 597 int main(int argc, char *argv[])
 598 {
 599         static char default_relay_path[] = "/relay";
 600         struct statfs st;
 601         int i, c;
 602         int stop_watch = 0;
 603         int act_mask_tmp = 0;
 604
 605         while ((c = getopt_long(argc, argv, S_OPTS, l_opts, NULL)) >= 0) {
 606                 switch (c) {
 607                 case 'a':
 608                         i = find_mask_map(optarg);
 609                         if (i < 0) {
 610                                 fprintf(stderr,"Invalid action mask %s\n",
 611                                         optarg);
 612                                 return 1;
 613                         }
 614                         act_mask_tmp |= i;
 615                         break;
 616
 617                 case 'A':
 618                         if ((sscanf(optarg, "%x", &i) != 1) || !VALID_SET(i)) {
 619                                 fprintf(stderr,
 620                                         "Invalid set action mask %s/0x%x\n",
 621                                         optarg, i);
 622                                 return 1;
 623                         }
 624                         act_mask_tmp = i;
 625                         break;
 626
 627                 case 'd':
 628                         if (resize_devices(optarg) != 0)
 629                                 return 1;
 630                         break;
 631
 632                 case 'r':
 633                         relay_path = optarg;
 634                         break;
 635
 636                 case 'o':
 637                         output_name = optarg;
 638                         break;
 639                 case 'k':
 640                         kill_running_trace = 1;
 641                         break;
 642                 case 'w':
 643                         stop_watch = atoi(optarg);
 644                         if (stop_watch <= 0) {
 645                                 fprintf(stderr,
 646                                         "Invalid stopwatch value (%d secs)\n",
 647                                         stop_watch);
 648                                 return 1;
 649                         }
 650                         break;
 651
 652                 default:
 653                         show_usage(argv[0]);
 654                         return 1;
 655                 }
 656         }
 657
 658         while (optind < argc) {
 659                 if (resize_devices(argv[optind++]) != 0)
 660                         return 1;
 661         }
 662
 663         if (ndevs == 0) {
 664                 show_usage(argv[0]);
 665                 return 1;
 666         }
 667
 668         if (!relay_path)
 669                 relay_path = default_relay_path;
 670
 671         if (act_mask_tmp != 0)
 672                 act_mask = act_mask_tmp;
 673
 674         if (statfs(relay_path, &st) < 0) {
 675                 perror("statfs");
 676                 fprintf(stderr,"%s does not appear to be a valid path\n",
 677                         relay_path);
 678                 return 1;
 679         } else if (st.f_type != RELAYFS_TYPE) {
 680                 fprintf(stderr,"%s does not appear to be a relay filesystem\n",
 681                         relay_path);
 682                 return 1;
 683         }
 684
 685         if (open_devices() != 0)
 686                 return 1;
 687
 688         if (kill_running_trace) {
 689                 stop_all_traces();
 690                 return 0;
 691         }
 692
 693         setlocale(LC_NUMERIC, "en_US");
 694
 695         ncpus = sysconf(_SC_NPROCESSORS_ONLN);
 696         if (ncpus < 0) {
 697                 fprintf(stderr, "sysconf(_SC_NPROCESSORS_ONLN) failed\n");
 698                 return 1;
 699         }
 700
 701         if (start_devices() != 0)
 702                 return 1;
 703
 704         signal(SIGINT, handle_sigint);
 705         signal(SIGHUP, handle_sigint);
 706         signal(SIGTERM, handle_sigint);
 707         signal(SIGALRM, handle_sigint);
 708
 709         atexit(stop_all_tracing);
 710
 711         if (stop_watch)
 712                 alarm(stop_watch);
 713
 714         while (!is_done())
 715                 sleep(1);
 716
 717         stop_all_threads();
 718         stop_all_traces();
 719         show_stats();
 720
 721         return 0;
 722 }
 723