kernel/tools/testing/selftests/mqueue/mq_perf_tests.c

   1 /*
   2  * This application is Copyright 2012 Red Hat, Inc.
   3  *      Doug Ledford <dledford@redhat.com>
   4  *
   5  * mq_perf_tests is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, version 3.
   8  *
   9  * mq_perf_tests is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * For the full text of the license, see <http://www.gnu.org/licenses/>.
  15  *
  16  * mq_perf_tests.c
  17  *   Tests various types of message queue workloads, concentrating on those
  18  *   situations that invole large message sizes, large message queue depths,
  19  *   or both, and reports back useful metrics about kernel message queue
  20  *   performance.
  21  *
  22  */
  23 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28 #include <string.h>
  29 #include <limits.h>
  30 #include <errno.h>
  31 #include <signal.h>
  32 #include <pthread.h>
  33 #include <sched.h>
  34 #include <sys/types.h>
  35 #include <sys/time.h>
  36 #include <sys/resource.h>
  37 #include <sys/stat.h>
  38 #include <mqueue.h>
  39 #include <popt.h>
  40 #include <error.h>
  41
  42 static char *usage =
  43 "Usage:\n"
  44 "  %s [-c #[,#..] -f] path\n"
  45 "\n"
  46 "       -c #    Skip most tests and go straight to a high queue depth test\n"
  47 "               and then run that test continuously (useful for running at\n"
  48 "               the same time as some other workload to see how much the\n"
  49 "               cache thrashing caused by adding messages to a very deep\n"
  50 "               queue impacts the performance of other programs).  The number\n"
  51 "               indicates which CPU core we should bind the process to during\n"
  52 "               the run.  If you have more than one physical CPU, then you\n"
  53 "               will need one copy per physical CPU package, and you should\n"
  54 "               specify the CPU cores to pin ourself to via a comma separated\n"
  55 "               list of CPU values.\n"
  56 "       -f      Only usable with continuous mode.  Pin ourself to the CPUs\n"
  57 "               as requested, then instead of looping doing a high mq\n"
  58 "               workload, just busy loop.  This will allow us to lock up a\n"
  59 "               single CPU just like we normally would, but without actually\n"
  60 "               thrashing the CPU cache.  This is to make it easier to get\n"
  61 "               comparable numbers from some other workload running on the\n"
  62 "               other CPUs.  One set of numbers with # CPUs locked up running\n"
  63 "               an mq workload, and another set of numbers with those same\n"
  64 "               CPUs locked away from the test workload, but not doing\n"
  65 "               anything to trash the cache like the mq workload might.\n"
  66 "       path    Path name of the message queue to create\n"
  67 "\n"
  68 "       Note: this program must be run as root in order to enable all tests\n"
  69 "\n";
  70
  71 char *MAX_MSGS = "/proc/sys/fs/mqueue/msg_max";
  72 char *MAX_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_max";
  73
  74 #define min(a, b) ((a) < (b) ? (a) : (b))
  75 #define MAX_CPUS 64
  76 char *cpu_option_string;
  77 int cpus_to_pin[MAX_CPUS];
  78 int num_cpus_to_pin;
  79 pthread_t cpu_threads[MAX_CPUS];
  80 pthread_t main_thread;
  81 cpu_set_t *cpu_set;
  82 int cpu_set_size;
  83 int cpus_online;
  84
  85 #define MSG_SIZE 16
  86 #define TEST1_LOOPS 10000000
  87 #define TEST2_LOOPS 100000
  88 int continuous_mode;
  89 int continuous_mode_fake;
  90
  91 struct rlimit saved_limits, cur_limits;
  92 int saved_max_msgs, saved_max_msgsize;
  93 int cur_max_msgs, cur_max_msgsize;
  94 FILE *max_msgs, *max_msgsize;
  95 int cur_nice;
  96 char *queue_path = "/mq_perf_tests";
  97 mqd_t queue = -1;
  98 struct mq_attr result;
  99 int mq_prio_max;
 100
 101 const struct poptOption options[] = {
 102         {
 103                 .longName = "continuous",
 104                 .shortName = 'c',
 105                 .argInfo = POPT_ARG_STRING,
 106                 .arg = &cpu_option_string,
 107                 .val = 'c',
 108                 .descrip = "Run continuous tests at a high queue depth in "
 109                         "order to test the effects of cache thrashing on "
 110                         "other tasks on the system.  This test is intended "
 111                         "to be run on one core of each physical CPU while "
 112                         "some other CPU intensive task is run on all the other "
 113                         "cores of that same physical CPU and the other task "
 114                         "is timed.  It is assumed that the process of adding "
 115                         "messages to the message queue in a tight loop will "
 116                         "impact that other task to some degree.  Once the "
 117                         "tests are performed in this way, you should then "
 118                         "re-run the tests using fake mode in order to check "
 119                         "the difference in time required to perform the CPU "
 120                         "intensive task",
 121                 .argDescrip = "cpu[,cpu]",
 122         },
 123         {
 124                 .longName = "fake",
 125                 .shortName = 'f',
 126                 .argInfo = POPT_ARG_NONE,
 127                 .arg = &continuous_mode_fake,
 128                 .val = 0,
 129                 .descrip = "Tie up the CPUs that we would normally tie up in"
 130                         "continuous mode, but don't actually do any mq stuff, "
 131                         "just keep the CPU busy so it can't be used to process "
 132                         "system level tasks as this would free up resources on "
 133                         "the other CPU cores and skew the comparison between "
 134                         "the no-mqueue work and mqueue work tests",
 135                 .argDescrip = NULL,
 136         },
 137         {
 138                 .longName = "path",
 139                 .shortName = 'p',
 140                 .argInfo = POPT_ARG_STRING | POPT_ARGFLAG_SHOW_DEFAULT,
 141                 .arg = &queue_path,
 142                 .val = 'p',
 143                 .descrip = "The name of the path to use in the mqueue "
 144                         "filesystem for our tests",
 145                 .argDescrip = "pathname",
 146         },
 147         POPT_AUTOHELP
 148         POPT_TABLEEND
 149 };
 150
 151 static inline void __set(FILE *stream, int value, char *err_msg);
 152 void shutdown(int exit_val, char *err_cause, int line_no);
 153 void sig_action_SIGUSR1(int signum, siginfo_t *info, void *context);
 154 void sig_action(int signum, siginfo_t *info, void *context);
 155 static inline int get(FILE *stream);
 156 static inline void set(FILE *stream, int value);
 157 static inline int try_set(FILE *stream, int value);
 158 static inline void getr(int type, struct rlimit *rlim);
 159 static inline void setr(int type, struct rlimit *rlim);
 160 static inline void open_queue(struct mq_attr *attr);
 161 void increase_limits(void);
 162
 163 static inline void __set(FILE *stream, int value, char *err_msg)
 164 {
 165         rewind(stream);
 166         if (fprintf(stream, "%d", value) < 0)
 167                 perror(err_msg);
 168 }
 169
 170
 171 void shutdown(int exit_val, char *err_cause, int line_no)
 172 {
 173         static int in_shutdown = 0;
 174         int errno_at_shutdown = errno;
 175         int i;
 176
 177         /* In case we get called by multiple threads or from an sighandler */
 178         if (in_shutdown++)
 179                 return;
 180
 181         for (i = 0; i < num_cpus_to_pin; i++)
 182                 if (cpu_threads[i]) {
 183                         pthread_kill(cpu_threads[i], SIGUSR1);
 184                         pthread_join(cpu_threads[i], NULL);
 185                 }
 186
 187         if (queue != -1)
 188                 if (mq_close(queue))
 189                         perror("mq_close() during shutdown");
 190         if (queue_path)
 191                 /*
 192                  * Be silent if this fails, if we cleaned up already it's
 193                  * expected to fail
 194                  */
 195                 mq_unlink(queue_path);
 196         if (saved_max_msgs)
 197                 __set(max_msgs, saved_max_msgs,
 198                       "failed to restore saved_max_msgs");
 199         if (saved_max_msgsize)
 200                 __set(max_msgsize, saved_max_msgsize,
 201                       "failed to restore saved_max_msgsize");
 202         if (exit_val)
 203                 error(exit_val, errno_at_shutdown, "%s at %d",
 204                       err_cause, line_no);
 205         exit(0);
 206 }
 207
 208 void sig_action_SIGUSR1(int signum, siginfo_t *info, void *context)
 209 {
 210         if (pthread_self() != main_thread)
 211                 pthread_exit(0);
 212         else {
 213                 fprintf(stderr, "Caught signal %d in SIGUSR1 handler, "
 214                                 "exiting\n", signum);
 215                 shutdown(0, "", 0);
 216                 fprintf(stderr, "\n\nReturned from shutdown?!?!\n\n");
 217                 exit(0);
 218         }
 219 }
 220
 221 void sig_action(int signum, siginfo_t *info, void *context)
 222 {
 223         if (pthread_self() != main_thread)
 224                 pthread_kill(main_thread, signum);
 225         else {
 226                 fprintf(stderr, "Caught signal %d, exiting\n", signum);
 227                 shutdown(0, "", 0);
 228                 fprintf(stderr, "\n\nReturned from shutdown?!?!\n\n");
 229                 exit(0);
 230         }
 231 }
 232
 233 static inline int get(FILE *stream)
 234 {
 235         int value;
 236         rewind(stream);
 237         if (fscanf(stream, "%d", &value) != 1)
 238                 shutdown(4, "Error reading /proc entry", __LINE__);
 239         return value;
 240 }
 241
 242 static inline void set(FILE *stream, int value)
 243 {
 244         int new_value;
 245
 246         rewind(stream);
 247         if (fprintf(stream, "%d", value) < 0)
 248                 return shutdown(5, "Failed writing to /proc file", __LINE__);
 249         new_value = get(stream);
 250         if (new_value != value)
 251                 return shutdown(5, "We didn't get what we wrote to /proc back",
 252                                 __LINE__);
 253 }
 254
 255 static inline int try_set(FILE *stream, int value)
 256 {
 257         int new_value;
 258
 259         rewind(stream);
 260         fprintf(stream, "%d", value);
 261         new_value = get(stream);
 262         return new_value == value;
 263 }
 264
 265 static inline void getr(int type, struct rlimit *rlim)
 266 {
 267         if (getrlimit(type, rlim))
 268                 shutdown(6, "getrlimit()", __LINE__);
 269 }
 270
 271 static inline void setr(int type, struct rlimit *rlim)
 272 {
 273         if (setrlimit(type, rlim))
 274                 shutdown(7, "setrlimit()", __LINE__);
 275 }
 276
 277 /**
 278  * open_queue - open the global queue for testing
 279  * @attr - An attr struct specifying the desired queue traits
 280  * @result - An attr struct that lists the actual traits the queue has
 281  *
 282  * This open is not allowed to fail, failure will result in an orderly
 283  * shutdown of the program.  The global queue_path is used to set what
 284  * queue to open, the queue descriptor is saved in the global queue
 285  * variable.
 286  */
 287 static inline void open_queue(struct mq_attr *attr)
 288 {
 289         int flags = O_RDWR | O_EXCL | O_CREAT | O_NONBLOCK;
 290         int perms = DEFFILEMODE;
 291
 292         queue = mq_open(queue_path, flags, perms, attr);
 293         if (queue == -1)
 294                 shutdown(1, "mq_open()", __LINE__);
 295         if (mq_getattr(queue, &result))
 296                 shutdown(1, "mq_getattr()", __LINE__);
 297         printf("\n\tQueue %s created:\n", queue_path);
 298         printf("\t\tmq_flags:\t\t\t%s\n", result.mq_flags & O_NONBLOCK ?
 299                "O_NONBLOCK" : "(null)");
 300         printf("\t\tmq_maxmsg:\t\t\t%lu\n", result.mq_maxmsg);
 301         printf("\t\tmq_msgsize:\t\t\t%lu\n", result.mq_msgsize);
 302         printf("\t\tmq_curmsgs:\t\t\t%lu\n", result.mq_curmsgs);
 303 }
 304
 305 void *fake_cont_thread(void *arg)
 306 {
 307         int i;
 308
 309         for (i = 0; i < num_cpus_to_pin; i++)
 310                 if (cpu_threads[i] == pthread_self())
 311                         break;
 312         printf("\tStarted fake continuous mode thread %d on CPU %d\n", i,
 313                cpus_to_pin[i]);
 314         while (1)
 315                 ;
 316 }
 317
 318 void *cont_thread(void *arg)
 319 {
 320         char buff[MSG_SIZE];
 321         int i, priority;
 322
 323         for (i = 0; i < num_cpus_to_pin; i++)
 324                 if (cpu_threads[i] == pthread_self())
 325                         break;
 326         printf("\tStarted continuous mode thread %d on CPU %d\n", i,
 327                cpus_to_pin[i]);
 328         while (1) {
 329                 while (mq_send(queue, buff, sizeof(buff), 0) == 0)
 330                         ;
 331                 mq_receive(queue, buff, sizeof(buff), &priority);
 332         }
 333 }
 334
 335 #define drain_queue() \
 336         while (mq_receive(queue, buff, MSG_SIZE, &prio_in) == MSG_SIZE)
 337
 338 #define do_untimed_send() \
 339         do { \
 340                 if (mq_send(queue, buff, MSG_SIZE, prio_out)) \
 341                         shutdown(3, "Test send failure", __LINE__); \
 342         } while (0)
 343
 344 #define do_send_recv() \
 345         do { \
 346                 clock_gettime(clock, &start); \
 347                 if (mq_send(queue, buff, MSG_SIZE, prio_out)) \
 348                         shutdown(3, "Test send failure", __LINE__); \
 349                 clock_gettime(clock, &middle); \
 350                 if (mq_receive(queue, buff, MSG_SIZE, &prio_in) != MSG_SIZE) \
 351                         shutdown(3, "Test receive failure", __LINE__); \
 352                 clock_gettime(clock, &end); \
 353                 nsec = ((middle.tv_sec - start.tv_sec) * 1000000000) + \
 354                         (middle.tv_nsec - start.tv_nsec); \
 355                 send_total.tv_nsec += nsec; \
 356                 if (send_total.tv_nsec >= 1000000000) { \
 357                         send_total.tv_sec++; \
 358                         send_total.tv_nsec -= 1000000000; \
 359                 } \
 360                 nsec = ((end.tv_sec - middle.tv_sec) * 1000000000) + \
 361                         (end.tv_nsec - middle.tv_nsec); \
 362                 recv_total.tv_nsec += nsec; \
 363                 if (recv_total.tv_nsec >= 1000000000) { \
 364                         recv_total.tv_sec++; \
 365                         recv_total.tv_nsec -= 1000000000; \
 366                 } \
 367         } while (0)
 368
 369 struct test {
 370         char *desc;
 371         void (*func)(int *);
 372 };
 373
 374 void const_prio(int *prio)
 375 {
 376         return;
 377 }
 378
 379 void inc_prio(int *prio)
 380 {
 381         if (++*prio == mq_prio_max)
 382                 *prio = 0;
 383 }
 384
 385 void dec_prio(int *prio)
 386 {
 387         if (--*prio < 0)
 388                 *prio = mq_prio_max - 1;
 389 }
 390
 391 void random_prio(int *prio)
 392 {
 393         *prio = random() % mq_prio_max;
 394 }
 395
 396 struct test test2[] = {
 397         {"\n\tTest #2a: Time send/recv message, queue full, constant prio\n",
 398                 const_prio},
 399         {"\n\tTest #2b: Time send/recv message, queue full, increasing prio\n",
 400                 inc_prio},
 401         {"\n\tTest #2c: Time send/recv message, queue full, decreasing prio\n",
 402                 dec_prio},
 403         {"\n\tTest #2d: Time send/recv message, queue full, random prio\n",
 404                 random_prio},
 405         {NULL, NULL}
 406 };
 407
 408 /**
 409  * Tests to perform (all done with MSG_SIZE messages):
 410  *
 411  * 1) Time to add/remove message with 0 messages on queue
 412  * 1a) with constant prio
 413  * 2) Time to add/remove message when queue close to capacity:
 414  * 2a) with constant prio
 415  * 2b) with increasing prio
 416  * 2c) with decreasing prio
 417  * 2d) with random prio
 418  * 3) Test limits of priorities honored (double check _SC_MQ_PRIO_MAX)
 419  */
 420 void *perf_test_thread(void *arg)
 421 {
 422         char buff[MSG_SIZE];
 423         int prio_out, prio_in;
 424         int i;
 425         clockid_t clock;
 426         pthread_t *t;
 427         struct timespec res, start, middle, end, send_total, recv_total;
 428         unsigned long long nsec;
 429         struct test *cur_test;
 430
 431         t = &cpu_threads[0];
 432         printf("\n\tStarted mqueue performance test thread on CPU %d\n",
 433                cpus_to_pin[0]);
 434         mq_prio_max = sysconf(_SC_MQ_PRIO_MAX);
 435         if (mq_prio_max == -1)
 436                 shutdown(2, "sysconf(_SC_MQ_PRIO_MAX)", __LINE__);
 437         if (pthread_getcpuclockid(cpu_threads[0], &clock) != 0)
 438                 shutdown(2, "pthread_getcpuclockid", __LINE__);
 439
 440         if (clock_getres(clock, &res))
 441                 shutdown(2, "clock_getres()", __LINE__);
 442
 443         printf("\t\tMax priorities:\t\t\t%d\n", mq_prio_max);
 444         printf("\t\tClock resolution:\t\t%lu nsec%s\n", res.tv_nsec,
 445                res.tv_nsec > 1 ? "s" : "");
 446
 447
 448
 449         printf("\n\tTest #1: Time send/recv message, queue empty\n");
 450         printf("\t\t(%d iterations)\n", TEST1_LOOPS);
 451         prio_out = 0;
 452         send_total.tv_sec = 0;
 453         send_total.tv_nsec = 0;
 454         recv_total.tv_sec = 0;
 455         recv_total.tv_nsec = 0;
 456         for (i = 0; i < TEST1_LOOPS; i++)
 457                 do_send_recv();
 458         printf("\t\tSend msg:\t\t\t%ld.%lus total time\n",
 459                send_total.tv_sec, send_total.tv_nsec);
 460         nsec = ((unsigned long long)send_total.tv_sec * 1000000000 +
 461                  send_total.tv_nsec) / TEST1_LOOPS;
 462         printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);
 463         printf("\t\tRecv msg:\t\t\t%ld.%lus total time\n",
 464                recv_total.tv_sec, recv_total.tv_nsec);
 465         nsec = ((unsigned long long)recv_total.tv_sec * 1000000000 +
 466                 recv_total.tv_nsec) / TEST1_LOOPS;
 467         printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);
 468
 469
 470         for (cur_test = test2; cur_test->desc != NULL; cur_test++) {
 471                 printf("%s:\n", cur_test->desc);
 472                 printf("\t\t(%d iterations)\n", TEST2_LOOPS);
 473                 prio_out = 0;
 474                 send_total.tv_sec = 0;
 475                 send_total.tv_nsec = 0;
 476                 recv_total.tv_sec = 0;
 477                 recv_total.tv_nsec = 0;
 478                 printf("\t\tFilling queue...");
 479                 fflush(stdout);
 480                 clock_gettime(clock, &start);
 481                 for (i = 0; i < result.mq_maxmsg - 1; i++) {
 482                         do_untimed_send();
 483                         cur_test->func(&prio_out);
 484                 }
 485                 clock_gettime(clock, &end);
 486                 nsec = ((unsigned long long)(end.tv_sec - start.tv_sec) *
 487                         1000000000) + (end.tv_nsec - start.tv_nsec);
 488                 printf("done.\t\t%lld.%llds\n", nsec / 1000000000,
 489                        nsec % 1000000000);
 490                 printf("\t\tTesting...");
 491                 fflush(stdout);
 492                 for (i = 0; i < TEST2_LOOPS; i++) {
 493                         do_send_recv();
 494                         cur_test->func(&prio_out);
 495                 }
 496                 printf("done.\n");
 497                 printf("\t\tSend msg:\t\t\t%ld.%lus total time\n",
 498                        send_total.tv_sec, send_total.tv_nsec);
 499                 nsec = ((unsigned long long)send_total.tv_sec * 1000000000 +
 500                          send_total.tv_nsec) / TEST2_LOOPS;
 501                 printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);
 502                 printf("\t\tRecv msg:\t\t\t%ld.%lus total time\n",
 503                        recv_total.tv_sec, recv_total.tv_nsec);
 504                 nsec = ((unsigned long long)recv_total.tv_sec * 1000000000 +
 505                         recv_total.tv_nsec) / TEST2_LOOPS;
 506                 printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);
 507                 printf("\t\tDraining queue...");
 508                 fflush(stdout);
 509                 clock_gettime(clock, &start);
 510                 drain_queue();
 511                 clock_gettime(clock, &end);
 512                 nsec = ((unsigned long long)(end.tv_sec - start.tv_sec) *
 513                         1000000000) + (end.tv_nsec - start.tv_nsec);
 514                 printf("done.\t\t%lld.%llds\n", nsec / 1000000000,
 515                        nsec % 1000000000);
 516         }
 517         return 0;
 518 }
 519
 520 void increase_limits(void)
 521 {
 522         cur_limits.rlim_cur = RLIM_INFINITY;
 523         cur_limits.rlim_max = RLIM_INFINITY;
 524         setr(RLIMIT_MSGQUEUE, &cur_limits);
 525         while (try_set(max_msgs, cur_max_msgs += 10))
 526                 ;
 527         cur_max_msgs = get(max_msgs);
 528         while (try_set(max_msgsize, cur_max_msgsize += 1024))
 529                 ;
 530         cur_max_msgsize = get(max_msgsize);
 531         if (setpriority(PRIO_PROCESS, 0, -20) != 0)
 532                 shutdown(2, "setpriority()", __LINE__);
 533         cur_nice = -20;
 534 }
 535
 536 int main(int argc, char *argv[])
 537 {
 538         struct mq_attr attr;
 539         char *option, *next_option;
 540         int i, cpu, rc;
 541         struct sigaction sa;
 542         poptContext popt_context;
 543         void *retval;
 544
 545         main_thread = pthread_self();
 546         num_cpus_to_pin = 0;
 547
 548         if (sysconf(_SC_NPROCESSORS_ONLN) == -1) {
 549                 perror("sysconf(_SC_NPROCESSORS_ONLN)");
 550                 exit(1);
 551         }
 552         cpus_online = min(MAX_CPUS, sysconf(_SC_NPROCESSORS_ONLN));
 553         cpu_set = CPU_ALLOC(cpus_online);
 554         if (cpu_set == NULL) {
 555                 perror("CPU_ALLOC()");
 556                 exit(1);
 557         }
 558         cpu_set_size = CPU_ALLOC_SIZE(cpus_online);
 559         CPU_ZERO_S(cpu_set_size, cpu_set);
 560
 561         popt_context = poptGetContext(NULL, argc, (const char **)argv,
 562                                       options, 0);
 563
 564         while ((rc = poptGetNextOpt(popt_context)) > 0) {
 565                 switch (rc) {
 566                 case 'c':
 567                         continuous_mode = 1;
 568                         option = cpu_option_string;
 569                         do {
 570                                 next_option = strchr(option, ',');
 571                                 if (next_option)
 572                                         *next_option = '\0';
 573                                 cpu = atoi(option);
 574                                 if (cpu >= cpus_online)
 575                                         fprintf(stderr, "CPU %d exceeds "
 576                                                 "cpus online, ignoring.\n",
 577                                                 cpu);
 578                                 else
 579                                         cpus_to_pin[num_cpus_to_pin++] = cpu;
 580                                 if (next_option)
 581                                         option = ++next_option;
 582                         } while (next_option && num_cpus_to_pin < MAX_CPUS);
 583                         /* Double check that they didn't give us the same CPU
 584                          * more than once */
 585                         for (cpu = 0; cpu < num_cpus_to_pin; cpu++) {
 586                                 if (CPU_ISSET_S(cpus_to_pin[cpu], cpu_set_size,
 587                                                 cpu_set)) {
 588                                         fprintf(stderr, "Any given CPU may "
 589                                                 "only be given once.\n");
 590                                         exit(1);
 591                                 } else
 592                                         CPU_SET_S(cpus_to_pin[cpu],
 593                                                   cpu_set_size, cpu_set);
 594                         }
 595                         break;
 596                 case 'p':
 597                         /*
 598                          * Although we can create a msg queue with a
 599                          * non-absolute path name, unlink will fail.  So,
 600                          * if the name doesn't start with a /, add one
 601                          * when we save it.
 602                          */
 603                         option = queue_path;
 604                         if (*option != '/') {
 605                                 queue_path = malloc(strlen(option) + 2);
 606                                 if (!queue_path) {
 607                                         perror("malloc()");
 608                                         exit(1);
 609                                 }
 610                                 queue_path[0] = '/';
 611                                 queue_path[1] = 0;
 612                                 strcat(queue_path, option);
 613                                 free(option);
 614                         }
 615                         break;
 616                 }
 617         }
 618
 619         if (continuous_mode && num_cpus_to_pin == 0) {
 620                 fprintf(stderr, "Must pass at least one CPU to continuous "
 621                         "mode.\n");
 622                 poptPrintUsage(popt_context, stderr, 0);
 623                 exit(1);
 624         } else if (!continuous_mode) {
 625                 num_cpus_to_pin = 1;
 626                 cpus_to_pin[0] = cpus_online - 1;
 627         }
 628
 629         if (getuid() != 0) {
 630                 fprintf(stderr, "Not running as root, but almost all tests "
 631                         "require root in order to modify\nsystem settings.  "
 632                         "Exiting.\n");
 633                 exit(1);
 634         }
 635
 636         max_msgs = fopen(MAX_MSGS, "r+");
 637         max_msgsize = fopen(MAX_MSGSIZE, "r+");
 638         if (!max_msgs)
 639                 shutdown(2, "Failed to open msg_max", __LINE__);
 640         if (!max_msgsize)
 641                 shutdown(2, "Failed to open msgsize_max", __LINE__);
 642
 643         /* Load up the current system values for everything we can */
 644         getr(RLIMIT_MSGQUEUE, &saved_limits);
 645         cur_limits = saved_limits;
 646         saved_max_msgs = cur_max_msgs = get(max_msgs);
 647         saved_max_msgsize = cur_max_msgsize = get(max_msgsize);
 648         errno = 0;
 649         cur_nice = getpriority(PRIO_PROCESS, 0);
 650         if (errno)
 651                 shutdown(2, "getpriority()", __LINE__);
 652
 653         /* Tell the user our initial state */
 654         printf("\nInitial system state:\n");
 655         printf("\tUsing queue path:\t\t\t%s\n", queue_path);
 656         printf("\tRLIMIT_MSGQUEUE(soft):\t\t\t%ld\n",
 657                 (long) saved_limits.rlim_cur);
 658         printf("\tRLIMIT_MSGQUEUE(hard):\t\t\t%ld\n",
 659                 (long) saved_limits.rlim_max);
 660         printf("\tMaximum Message Size:\t\t\t%d\n", saved_max_msgsize);
 661         printf("\tMaximum Queue Size:\t\t\t%d\n", saved_max_msgs);
 662         printf("\tNice value:\t\t\t\t%d\n", cur_nice);
 663         printf("\n");
 664
 665         increase_limits();
 666
 667         printf("Adjusted system state for testing:\n");
 668         if (cur_limits.rlim_cur == RLIM_INFINITY) {
 669                 printf("\tRLIMIT_MSGQUEUE(soft):\t\t\t(unlimited)\n");
 670                 printf("\tRLIMIT_MSGQUEUE(hard):\t\t\t(unlimited)\n");
 671         } else {
 672                 printf("\tRLIMIT_MSGQUEUE(soft):\t\t\t%ld\n",
 673                        (long) cur_limits.rlim_cur);
 674                 printf("\tRLIMIT_MSGQUEUE(hard):\t\t\t%ld\n",
 675                        (long) cur_limits.rlim_max);
 676         }
 677         printf("\tMaximum Message Size:\t\t\t%d\n", cur_max_msgsize);
 678         printf("\tMaximum Queue Size:\t\t\t%d\n", cur_max_msgs);
 679         printf("\tNice value:\t\t\t\t%d\n", cur_nice);
 680         printf("\tContinuous mode:\t\t\t(%s)\n", continuous_mode ?
 681                (continuous_mode_fake ? "fake mode" : "enabled") :
 682                "disabled");
 683         printf("\tCPUs to pin:\t\t\t\t%d", cpus_to_pin[0]);
 684         for (cpu = 1; cpu < num_cpus_to_pin; cpu++)
 685                         printf(",%d", cpus_to_pin[cpu]);
 686         printf("\n");
 687
 688         sa.sa_sigaction = sig_action_SIGUSR1;
 689         sigemptyset(&sa.sa_mask);
 690         sigaddset(&sa.sa_mask, SIGHUP);
 691         sigaddset(&sa.sa_mask, SIGINT);
 692         sigaddset(&sa.sa_mask, SIGQUIT);
 693         sigaddset(&sa.sa_mask, SIGTERM);
 694         sa.sa_flags = SA_SIGINFO;
 695         if (sigaction(SIGUSR1, &sa, NULL) == -1)
 696                 shutdown(1, "sigaction(SIGUSR1)", __LINE__);
 697         sa.sa_sigaction = sig_action;
 698         if (sigaction(SIGHUP, &sa, NULL) == -1)
 699                 shutdown(1, "sigaction(SIGHUP)", __LINE__);
 700         if (sigaction(SIGINT, &sa, NULL) == -1)
 701                 shutdown(1, "sigaction(SIGINT)", __LINE__);
 702         if (sigaction(SIGQUIT, &sa, NULL) == -1)
 703                 shutdown(1, "sigaction(SIGQUIT)", __LINE__);
 704         if (sigaction(SIGTERM, &sa, NULL) == -1)
 705                 shutdown(1, "sigaction(SIGTERM)", __LINE__);
 706
 707         if (!continuous_mode_fake) {
 708                 attr.mq_flags = O_NONBLOCK;
 709                 attr.mq_maxmsg = cur_max_msgs;
 710                 attr.mq_msgsize = MSG_SIZE;
 711                 open_queue(&attr);
 712         }
 713         for (i = 0; i < num_cpus_to_pin; i++) {
 714                 pthread_attr_t thread_attr;
 715                 void *thread_func;
 716
 717                 if (continuous_mode_fake)
 718                         thread_func = &fake_cont_thread;
 719                 else if (continuous_mode)
 720                         thread_func = &cont_thread;
 721                 else
 722                         thread_func = &perf_test_thread;
 723
 724                 CPU_ZERO_S(cpu_set_size, cpu_set);
 725                 CPU_SET_S(cpus_to_pin[i], cpu_set_size, cpu_set);
 726                 pthread_attr_init(&thread_attr);
 727                 pthread_attr_setaffinity_np(&thread_attr, cpu_set_size,
 728                                             cpu_set);
 729                 if (pthread_create(&cpu_threads[i], &thread_attr, thread_func,
 730                                    NULL))
 731                         shutdown(1, "pthread_create()", __LINE__);
 732                 pthread_attr_destroy(&thread_attr);
 733         }
 734
 735         if (!continuous_mode) {
 736                 pthread_join(cpu_threads[0], &retval);
 737                 shutdown((long)retval, "perf_test_thread()", __LINE__);
 738         } else {
 739                 while (1)
 740                         sleep(1);
 741         }
 742         shutdown(0, "", 0);
 743 }