/*
 * This application is Copyright 2012 Red Hat, Inc.
 *      Doug Ledford <dledford@redhat.com>
 *
 * mq_perf_tests is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * mq_perf_tests is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * For the full text of the license, see <http://www.gnu.org/licenses/>.
 *
 * mq_perf_tests.c
 *   Tests various types of message queue workloads, concentrating on those
 *   situations that invole large message sizes, large message queue depths,
 *   or both, and reports back useful metrics about kernel message queue
 *   performance.
 *
 */
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <limits.h>
#include <errno.h>
#include <signal.h>
#include <pthread.h>
#include <sched.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <mqueue.h>
#include <popt.h>
#include <error.h>

#include "kselftest.h"

static char *usage =
"Usage:\n"
"  %s [-c #[,#..] -f] path\n"
"\n"
"       -c #    Skip most tests and go straight to a high queue depth test\n"
"               and then run that test continuously (useful for running at\n"
"               the same time as some other workload to see how much the\n"
"               cache thrashing caused by adding messages to a very deep\n"
"               queue impacts the performance of other programs).  The number\n"
"               indicates which CPU core we should bind the process to during\n"
"               the run.  If you have more than one physical CPU, then you\n"
"               will need one copy per physical CPU package, and you should\n"
"               specify the CPU cores to pin ourself to via a comma separated\n"
"               list of CPU values.\n"
"       -f      Only usable with continuous mode.  Pin ourself to the CPUs\n"
"               as requested, then instead of looping doing a high mq\n"
"               workload, just busy loop.  This will allow us to lock up a\n"
"               single CPU just like we normally would, but without actually\n"
"               thrashing the CPU cache.  This is to make it easier to get\n"
"               comparable numbers from some other workload running on the\n"
"               other CPUs.  One set of numbers with # CPUs locked up running\n"
"               an mq workload, and another set of numbers with those same\n"
"               CPUs locked away from the test workload, but not doing\n"
"               anything to trash the cache like the mq workload might.\n"
"       path    Path name of the message queue to create\n"
"\n"
"       Note: this program must be run as root in order to enable all tests\n"
"\n";

char *MAX_MSGS = "/proc/sys/fs/mqueue/msg_max";
char *MAX_MSGSIZE = "/proc/sys/fs/mqueue/msgsize_max";

#define MAX_CPUS 64
char *cpu_option_string;
int cpus_to_pin[MAX_CPUS];
int num_cpus_to_pin;
pthread_t cpu_threads[MAX_CPUS];
pthread_t main_thread;
cpu_set_t *cpu_set;
int cpu_set_size;
int cpus_online;

#define MSG_SIZE 16
#define TEST1_LOOPS 10000000
#define TEST2_LOOPS 100000
int continuous_mode;
int continuous_mode_fake;

struct rlimit saved_limits, cur_limits;
int saved_max_msgs, saved_max_msgsize;
int cur_max_msgs, cur_max_msgsize;
FILE *max_msgs, *max_msgsize;
int cur_nice;
char *queue_path = "/mq_perf_tests";
mqd_t queue = -1;
struct mq_attr result;
int mq_prio_max;

const struct poptOption options[] = {
        {
                .longName = "continuous",
                .shortName = 'c',
                .argInfo = POPT_ARG_STRING,
                .arg = &cpu_option_string,
                .val = 'c',
                .descrip = "Run continuous tests at a high queue depth in "
                        "order to test the effects of cache thrashing on "
                        "other tasks on the system.  This test is intended "
                        "to be run on one core of each physical CPU while "
                        "some other CPU intensive task is run on all the other "
                        "cores of that same physical CPU and the other task "
                        "is timed.  It is assumed that the process of adding "
                        "messages to the message queue in a tight loop will "
                        "impact that other task to some degree.  Once the "
                        "tests are performed in this way, you should then "
                        "re-run the tests using fake mode in order to check "
                        "the difference in time required to perform the CPU "
                        "intensive task",
                .argDescrip = "cpu[,cpu]",
        },
        {
                .longName = "fake",
                .shortName = 'f',
                .argInfo = POPT_ARG_NONE,
                .arg = &continuous_mode_fake,
                .val = 0,
                .descrip = "Tie up the CPUs that we would normally tie up in"
                        "continuous mode, but don't actually do any mq stuff, "
                        "just keep the CPU busy so it can't be used to process "
                        "system level tasks as this would free up resources on "
                        "the other CPU cores and skew the comparison between "
                        "the no-mqueue work and mqueue work tests",
                .argDescrip = NULL,
        },
        {
                .longName = "path",
                .shortName = 'p',
                .argInfo = POPT_ARG_STRING | POPT_ARGFLAG_SHOW_DEFAULT,
                .arg = &queue_path,
                .val = 'p',
                .descrip = "The name of the path to use in the mqueue "
                        "filesystem for our tests",
                .argDescrip = "pathname",
        },
        POPT_AUTOHELP
        POPT_TABLEEND
};

static inline void __set(FILE *stream, int value, char *err_msg);
void shutdown(int exit_val, char *err_cause, int line_no);
void sig_action_SIGUSR1(int signum, siginfo_t *info, void *context);
void sig_action(int signum, siginfo_t *info, void *context);
static inline int get(FILE *stream);
static inline void set(FILE *stream, int value);
static inline int try_set(FILE *stream, int value);
static inline void getr(int type, struct rlimit *rlim);
static inline void setr(int type, struct rlimit *rlim);
static inline void open_queue(struct mq_attr *attr);
void increase_limits(void);

static inline void __set(FILE *stream, int value, char *err_msg)
{
        rewind(stream);
        if (fprintf(stream, "%d", value) < 0)
                perror(err_msg);
}


void shutdown(int exit_val, char *err_cause, int line_no)
{
        static int in_shutdown = 0;
        int errno_at_shutdown = errno;
        int i;

        /* In case we get called by multiple threads or from an sighandler */
        if (in_shutdown++)
                return;

        /* Free the cpu_set allocated using CPU_ALLOC in main function */
        CPU_FREE(cpu_set);

        for (i = 0; i < num_cpus_to_pin; i++)
                if (cpu_threads[i]) {
                        pthread_kill(cpu_threads[i], SIGUSR1);
                        pthread_join(cpu_threads[i], NULL);
                }

        if (queue != -1)
                if (mq_close(queue))
                        perror("mq_close() during shutdown");
        if (queue_path)
                /*
                 * Be silent if this fails, if we cleaned up already it's
                 * expected to fail
                 */
                mq_unlink(queue_path);
        if (saved_max_msgs)
                __set(max_msgs, saved_max_msgs,
                      "failed to restore saved_max_msgs");
        if (saved_max_msgsize)
                __set(max_msgsize, saved_max_msgsize,
                      "failed to restore saved_max_msgsize");
        if (exit_val)
                error(exit_val, errno_at_shutdown, "%s at %d",
                      err_cause, line_no);
        exit(0);
}

void sig_action_SIGUSR1(int signum, siginfo_t *info, void *context)
{
        if (pthread_self() != main_thread)
                pthread_exit(0);
        else {
                fprintf(stderr, "Caught signal %d in SIGUSR1 handler, "
                                "exiting\n", signum);
                shutdown(0, "", 0);
                fprintf(stderr, "\n\nReturned from shutdown?!?!\n\n");
                exit(0);
        }
}

void sig_action(int signum, siginfo_t *info, void *context)
{
        if (pthread_self() != main_thread)
                pthread_kill(main_thread, signum);
        else {
                fprintf(stderr, "Caught signal %d, exiting\n", signum);
                shutdown(0, "", 0);
                fprintf(stderr, "\n\nReturned from shutdown?!?!\n\n");
                exit(0);
        }
}

static inline int get(FILE *stream)
{
        int value;
        rewind(stream);
        if (fscanf(stream, "%d", &value) != 1)
                shutdown(4, "Error reading /proc entry", __LINE__);
        return value;
}

static inline void set(FILE *stream, int value)
{
        int new_value;

        rewind(stream);
        if (fprintf(stream, "%d", value) < 0)
                return shutdown(5, "Failed writing to /proc file", __LINE__);
        new_value = get(stream);
        if (new_value != value)
                return shutdown(5, "We didn't get what we wrote to /proc back",
                                __LINE__);
}

static inline int try_set(FILE *stream, int value)
{
        int new_value;

        rewind(stream);
        fprintf(stream, "%d", value);
        new_value = get(stream);
        return new_value == value;
}

static inline void getr(int type, struct rlimit *rlim)
{
        if (getrlimit(type, rlim))
                shutdown(6, "getrlimit()", __LINE__);
}

static inline void setr(int type, struct rlimit *rlim)
{
        if (setrlimit(type, rlim))
                shutdown(7, "setrlimit()", __LINE__);
}

/**
 * open_queue - open the global queue for testing
 * @attr - An attr struct specifying the desired queue traits
 * @result - An attr struct that lists the actual traits the queue has
 *
 * This open is not allowed to fail, failure will result in an orderly
 * shutdown of the program.  The global queue_path is used to set what
 * queue to open, the queue descriptor is saved in the global queue
 * variable.
 */
static inline void open_queue(struct mq_attr *attr)
{
        int flags = O_RDWR | O_EXCL | O_CREAT | O_NONBLOCK;
        int perms = DEFFILEMODE;

        queue = mq_open(queue_path, flags, perms, attr);
        if (queue == -1)
                shutdown(1, "mq_open()", __LINE__);
        if (mq_getattr(queue, &result))
                shutdown(1, "mq_getattr()", __LINE__);
        printf("\n\tQueue %s created:\n", queue_path);
        printf("\t\tmq_flags:\t\t\t%s\n", result.mq_flags & O_NONBLOCK ?
               "O_NONBLOCK" : "(null)");
        printf("\t\tmq_maxmsg:\t\t\t%lu\n", result.mq_maxmsg);
        printf("\t\tmq_msgsize:\t\t\t%lu\n", result.mq_msgsize);
        printf("\t\tmq_curmsgs:\t\t\t%lu\n", result.mq_curmsgs);
}

void *fake_cont_thread(void *arg)
{
        int i;

        for (i = 0; i < num_cpus_to_pin; i++)
                if (cpu_threads[i] == pthread_self())
                        break;
        printf("\tStarted fake continuous mode thread %d on CPU %d\n", i,
               cpus_to_pin[i]);
        while (1)
                ;
}

void *cont_thread(void *arg)
{
        char buff[MSG_SIZE];
        int i;
        unsigned int priority;

        for (i = 0; i < num_cpus_to_pin; i++)
                if (cpu_threads[i] == pthread_self())
                        break;
        printf("\tStarted continuous mode thread %d on CPU %d\n", i,
               cpus_to_pin[i]);
        while (1) {
                while (mq_send(queue, buff, sizeof(buff), 0) == 0)
                        ;
                mq_receive(queue, buff, sizeof(buff), &priority);
        }
}

#define drain_queue() \
        while (mq_receive(queue, buff, MSG_SIZE, &prio_in) == MSG_SIZE)

#define do_untimed_send() \
        do { \
                if (mq_send(queue, buff, MSG_SIZE, prio_out)) \
                        shutdown(3, "Test send failure", __LINE__); \
        } while (0)

#define do_send_recv() \
        do { \
                clock_gettime(clock, &start); \
                if (mq_send(queue, buff, MSG_SIZE, prio_out)) \
                        shutdown(3, "Test send failure", __LINE__); \
                clock_gettime(clock, &middle); \
                if (mq_receive(queue, buff, MSG_SIZE, &prio_in) != MSG_SIZE) \
                        shutdown(3, "Test receive failure", __LINE__); \
                clock_gettime(clock, &end); \
                nsec = ((middle.tv_sec - start.tv_sec) * 1000000000) + \
                        (middle.tv_nsec - start.tv_nsec); \
                send_total.tv_nsec += nsec; \
                if (send_total.tv_nsec >= 1000000000) { \
                        send_total.tv_sec++; \
                        send_total.tv_nsec -= 1000000000; \
                } \
                nsec = ((end.tv_sec - middle.tv_sec) * 1000000000) + \
                        (end.tv_nsec - middle.tv_nsec); \
                recv_total.tv_nsec += nsec; \
                if (recv_total.tv_nsec >= 1000000000) { \
                        recv_total.tv_sec++; \
                        recv_total.tv_nsec -= 1000000000; \
                } \
        } while (0)

struct test {
        char *desc;
        void (*func)(int *);
};

void const_prio(int *prio)
{
        return;
}

void inc_prio(int *prio)
{
        if (++*prio == mq_prio_max)
                *prio = 0;
}

void dec_prio(int *prio)
{
        if (--*prio < 0)
                *prio = mq_prio_max - 1;
}

void random_prio(int *prio)
{
        *prio = random() % mq_prio_max;
}

struct test test2[] = {
        {"\n\tTest #2a: Time send/recv message, queue full, constant prio\n",
                const_prio},
        {"\n\tTest #2b: Time send/recv message, queue full, increasing prio\n",
                inc_prio},
        {"\n\tTest #2c: Time send/recv message, queue full, decreasing prio\n",
                dec_prio},
        {"\n\tTest #2d: Time send/recv message, queue full, random prio\n",
                random_prio},
        {NULL, NULL}
};

/**
 * Tests to perform (all done with MSG_SIZE messages):
 *
 * 1) Time to add/remove message with 0 messages on queue
 * 1a) with constant prio
 * 2) Time to add/remove message when queue close to capacity:
 * 2a) with constant prio
 * 2b) with increasing prio
 * 2c) with decreasing prio
 * 2d) with random prio
 * 3) Test limits of priorities honored (double check _SC_MQ_PRIO_MAX)
 */
void *perf_test_thread(void *arg)
{
        char buff[MSG_SIZE];
        int prio_out;
        unsigned int prio_in;
        int i;
        clockid_t clock;
        pthread_t *t;
        struct timespec res, start, middle, end, send_total, recv_total;
        unsigned long long nsec;
        struct test *cur_test;

        t = &cpu_threads[0];
        printf("\n\tStarted mqueue performance test thread on CPU %d\n",
               cpus_to_pin[0]);
        mq_prio_max = sysconf(_SC_MQ_PRIO_MAX);
        if (mq_prio_max == -1)
                shutdown(2, "sysconf(_SC_MQ_PRIO_MAX)", __LINE__);
        if (pthread_getcpuclockid(cpu_threads[0], &clock) != 0)
                shutdown(2, "pthread_getcpuclockid", __LINE__);

        if (clock_getres(clock, &res))
                shutdown(2, "clock_getres()", __LINE__);

        printf("\t\tMax priorities:\t\t\t%d\n", mq_prio_max);
        printf("\t\tClock resolution:\t\t%lu nsec%s\n", res.tv_nsec,
               res.tv_nsec > 1 ? "s" : "");



        printf("\n\tTest #1: Time send/recv message, queue empty\n");
        printf("\t\t(%d iterations)\n", TEST1_LOOPS);
        prio_out = 0;
        send_total.tv_sec = 0;
        send_total.tv_nsec = 0;
        recv_total.tv_sec = 0;
        recv_total.tv_nsec = 0;
        for (i = 0; i < TEST1_LOOPS; i++)
                do_send_recv();
        printf("\t\tSend msg:\t\t\t%ld.%lus total time\n",
               send_total.tv_sec, send_total.tv_nsec);
        nsec = ((unsigned long long)send_total.tv_sec * 1000000000 +
                 send_total.tv_nsec) / TEST1_LOOPS;
        printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);
        printf("\t\tRecv msg:\t\t\t%ld.%lus total time\n",
               recv_total.tv_sec, recv_total.tv_nsec);
        nsec = ((unsigned long long)recv_total.tv_sec * 1000000000 +
                recv_total.tv_nsec) / TEST1_LOOPS;
        printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);


        for (cur_test = test2; cur_test->desc != NULL; cur_test++) {
                printf("%s:\n", cur_test->desc);
                printf("\t\t(%d iterations)\n", TEST2_LOOPS);
                prio_out = 0;
                send_total.tv_sec = 0;
                send_total.tv_nsec = 0;
                recv_total.tv_sec = 0;
                recv_total.tv_nsec = 0;
                printf("\t\tFilling queue...");
                fflush(stdout);
                clock_gettime(clock, &start);
                for (i = 0; i < result.mq_maxmsg - 1; i++) {
                        do_untimed_send();
                        cur_test->func(&prio_out);
                }
                clock_gettime(clock, &end);
                nsec = ((unsigned long long)(end.tv_sec - start.tv_sec) *
                        1000000000) + (end.tv_nsec - start.tv_nsec);
                printf("done.\t\t%lld.%llds\n", nsec / 1000000000,
                       nsec % 1000000000);
                printf("\t\tTesting...");
                fflush(stdout);
                for (i = 0; i < TEST2_LOOPS; i++) {
                        do_send_recv();
                        cur_test->func(&prio_out);
                }
                printf("done.\n");
                printf("\t\tSend msg:\t\t\t%ld.%lus total time\n",
                       send_total.tv_sec, send_total.tv_nsec);
                nsec = ((unsigned long long)send_total.tv_sec * 1000000000 +
                         send_total.tv_nsec) / TEST2_LOOPS;
                printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);
                printf("\t\tRecv msg:\t\t\t%ld.%lus total time\n",
                       recv_total.tv_sec, recv_total.tv_nsec);
                nsec = ((unsigned long long)recv_total.tv_sec * 1000000000 +
                        recv_total.tv_nsec) / TEST2_LOOPS;
                printf("\t\t\t\t\t\t%lld nsec/msg\n", nsec);
                printf("\t\tDraining queue...");
                fflush(stdout);
                clock_gettime(clock, &start);
                drain_queue();
                clock_gettime(clock, &end);
                nsec = ((unsigned long long)(end.tv_sec - start.tv_sec) *
                        1000000000) + (end.tv_nsec - start.tv_nsec);
                printf("done.\t\t%lld.%llds\n", nsec / 1000000000,
                       nsec % 1000000000);
        }
        return 0;
}

void increase_limits(void)
{
        cur_limits.rlim_cur = RLIM_INFINITY;
        cur_limits.rlim_max = RLIM_INFINITY;
        setr(RLIMIT_MSGQUEUE, &cur_limits);
        while (try_set(max_msgs, cur_max_msgs += 10))
                ;
        cur_max_msgs = get(max_msgs);
        while (try_set(max_msgsize, cur_max_msgsize += 1024))
                ;
        cur_max_msgsize = get(max_msgsize);
        if (setpriority(PRIO_PROCESS, 0, -20) != 0)
                shutdown(2, "setpriority()", __LINE__);
        cur_nice = -20;
}

int main(int argc, char *argv[])
{
        struct mq_attr attr;
        char *option, *next_option;
        int i, cpu, rc;
        struct sigaction sa;
        poptContext popt_context;
        void *retval;

        main_thread = pthread_self();
        num_cpus_to_pin = 0;

        if (sysconf(_SC_NPROCESSORS_ONLN) == -1) {
                perror("sysconf(_SC_NPROCESSORS_ONLN)");
                exit(1);
        }

        if (getuid() != 0)
                ksft_exit_skip("Not running as root, but almost all tests "
                        "require root in order to modify\nsystem settings.  "
                        "Exiting.\n");

        cpus_online = MIN(MAX_CPUS, sysconf(_SC_NPROCESSORS_ONLN));
        cpu_set = CPU_ALLOC(cpus_online);
        if (cpu_set == NULL) {
                perror("CPU_ALLOC()");
                exit(1);
        }
        cpu_set_size = CPU_ALLOC_SIZE(cpus_online);
        CPU_ZERO_S(cpu_set_size, cpu_set);

        popt_context = poptGetContext(NULL, argc, (const char **)argv,
                                      options, 0);

        while ((rc = poptGetNextOpt(popt_context)) > 0) {
                switch (rc) {
                case 'c':
                        continuous_mode = 1;
                        option = cpu_option_string;
                        do {
                                next_option = strchr(option, ',');
                                if (next_option)
                                        *next_option = '\0';
                                cpu = atoi(option);
                                if (cpu >= cpus_online)
                                        fprintf(stderr, "CPU %d exceeds "
                                                "cpus online, ignoring.\n",
                                                cpu);
                                else
                                        cpus_to_pin[num_cpus_to_pin++] = cpu;
                                if (next_option)
                                        option = ++next_option;
                        } while (next_option && num_cpus_to_pin < MAX_CPUS);
                        /* Double check that they didn't give us the same CPU
                         * more than once */
                        for (cpu = 0; cpu < num_cpus_to_pin; cpu++) {
                                if (CPU_ISSET_S(cpus_to_pin[cpu], cpu_set_size,
                                                cpu_set)) {
                                        fprintf(stderr, "Any given CPU may "
                                                "only be given once.\n");
                                        goto err_code;
                                } else
                                        CPU_SET_S(cpus_to_pin[cpu],
                                                  cpu_set_size, cpu_set);
                        }
                        break;
                case 'p':
                        /*
                         * Although we can create a msg queue with a
                         * non-absolute path name, unlink will fail.  So,
                         * if the name doesn't start with a /, add one
                         * when we save it.
                         */
                        option = queue_path;
                        if (*option != '/') {
                                queue_path = malloc(strlen(option) + 2);
                                if (!queue_path) {
                                        perror("malloc()");
                                        goto err_code;
                                }
                                queue_path[0] = '/';
                                queue_path[1] = 0;
                                strcat(queue_path, option);
                                free(option);
                        }
                        break;
                }
        }

        if (continuous_mode && num_cpus_to_pin == 0) {
                fprintf(stderr, "Must pass at least one CPU to continuous "
                        "mode.\n");
                poptPrintUsage(popt_context, stderr, 0);
                goto err_code;
        } else if (!continuous_mode) {
                num_cpus_to_pin = 1;
                cpus_to_pin[0] = cpus_online - 1;
        }

        max_msgs = fopen(MAX_MSGS, "r+");
        max_msgsize = fopen(MAX_MSGSIZE, "r+");
        if (!max_msgs)
                shutdown(2, "Failed to open msg_max", __LINE__);
        if (!max_msgsize)
                shutdown(2, "Failed to open msgsize_max", __LINE__);

        /* Load up the current system values for everything we can */
        getr(RLIMIT_MSGQUEUE, &saved_limits);
        cur_limits = saved_limits;
        saved_max_msgs = cur_max_msgs = get(max_msgs);
        saved_max_msgsize = cur_max_msgsize = get(max_msgsize);
        errno = 0;
        cur_nice = getpriority(PRIO_PROCESS, 0);
        if (errno)
                shutdown(2, "getpriority()", __LINE__);

        /* Tell the user our initial state */
        printf("\nInitial system state:\n");
        printf("\tUsing queue path:\t\t\t%s\n", queue_path);
        printf("\tRLIMIT_MSGQUEUE(soft):\t\t\t%ld\n",
                (long) saved_limits.rlim_cur);
        printf("\tRLIMIT_MSGQUEUE(hard):\t\t\t%ld\n",
                (long) saved_limits.rlim_max);
        printf("\tMaximum Message Size:\t\t\t%d\n", saved_max_msgsize);
        printf("\tMaximum Queue Size:\t\t\t%d\n", saved_max_msgs);
        printf("\tNice value:\t\t\t\t%d\n", cur_nice);
        printf("\n");

        increase_limits();

        printf("Adjusted system state for testing:\n");
        if (cur_limits.rlim_cur == RLIM_INFINITY) {
                printf("\tRLIMIT_MSGQUEUE(soft):\t\t\t(unlimited)\n");
                printf("\tRLIMIT_MSGQUEUE(hard):\t\t\t(unlimited)\n");
        } else {
                printf("\tRLIMIT_MSGQUEUE(soft):\t\t\t%ld\n",
                       (long) cur_limits.rlim_cur);
                printf("\tRLIMIT_MSGQUEUE(hard):\t\t\t%ld\n",
                       (long) cur_limits.rlim_max);
        }
        printf("\tMaximum Message Size:\t\t\t%d\n", cur_max_msgsize);
        printf("\tMaximum Queue Size:\t\t\t%d\n", cur_max_msgs);
        printf("\tNice value:\t\t\t\t%d\n", cur_nice);
        printf("\tContinuous mode:\t\t\t(%s)\n", continuous_mode ?
               (continuous_mode_fake ? "fake mode" : "enabled") :
               "disabled");
        printf("\tCPUs to pin:\t\t\t\t%d", cpus_to_pin[0]);
        for (cpu = 1; cpu < num_cpus_to_pin; cpu++)
                        printf(",%d", cpus_to_pin[cpu]);
        printf("\n");

        sa.sa_sigaction = sig_action_SIGUSR1;
        sigemptyset(&sa.sa_mask);
        sigaddset(&sa.sa_mask, SIGHUP);
        sigaddset(&sa.sa_mask, SIGINT);
        sigaddset(&sa.sa_mask, SIGQUIT);
        sigaddset(&sa.sa_mask, SIGTERM);
        sa.sa_flags = SA_SIGINFO;
        if (sigaction(SIGUSR1, &sa, NULL) == -1)
                shutdown(1, "sigaction(SIGUSR1)", __LINE__);
        sa.sa_sigaction = sig_action;
        if (sigaction(SIGHUP, &sa, NULL) == -1)
                shutdown(1, "sigaction(SIGHUP)", __LINE__);
        if (sigaction(SIGINT, &sa, NULL) == -1)
                shutdown(1, "sigaction(SIGINT)", __LINE__);
        if (sigaction(SIGQUIT, &sa, NULL) == -1)
                shutdown(1, "sigaction(SIGQUIT)", __LINE__);
        if (sigaction(SIGTERM, &sa, NULL) == -1)
                shutdown(1, "sigaction(SIGTERM)", __LINE__);

        if (!continuous_mode_fake) {
                attr.mq_flags = O_NONBLOCK;
                attr.mq_maxmsg = cur_max_msgs;
                attr.mq_msgsize = MSG_SIZE;
                open_queue(&attr);
        }
        for (i = 0; i < num_cpus_to_pin; i++) {
                pthread_attr_t thread_attr;
                void *thread_func;

                if (continuous_mode_fake)
                        thread_func = &fake_cont_thread;
                else if (continuous_mode)
                        thread_func = &cont_thread;
                else
                        thread_func = &perf_test_thread;

                CPU_ZERO_S(cpu_set_size, cpu_set);
                CPU_SET_S(cpus_to_pin[i], cpu_set_size, cpu_set);
                pthread_attr_init(&thread_attr);
                pthread_attr_setaffinity_np(&thread_attr, cpu_set_size,
                                            cpu_set);
                if (pthread_create(&cpu_threads[i], &thread_attr, thread_func,
                                   NULL))
                        shutdown(1, "pthread_create()", __LINE__);
                pthread_attr_destroy(&thread_attr);
        }

        if (!continuous_mode) {
                pthread_join(cpu_threads[0], &retval);
                shutdown((long)retval, "perf_test_thread()", __LINE__);
        } else {
                while (1)
                        sleep(1);
        }
        shutdown(0, "", 0);

err_code:
        CPU_FREE(cpu_set);
        exit(1);

}