builtin-stat.c

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/*
 * builtin-stat.c
 *
 * Builtin stat command: Give a precise performance counters summary
 * overview about any workload, CPU or specific PID.
 *
 * Sample output:

   $ perf stat ./hackbench 10

  Time: 0.118

  Performance counter stats for './hackbench 10':

       1708.761321 task-clock                #   11.037 CPUs utilized
            41,190 context-switches          #    0.024 M/sec
             6,735 CPU-migrations            #    0.004 M/sec
            17,318 page-faults               #    0.010 M/sec
     5,205,202,243 cycles                    #    3.046 GHz
     3,856,436,920 stalled-cycles-frontend   #   74.09% frontend cycles idle
     1,600,790,871 stalled-cycles-backend    #   30.75% backend  cycles idle
     2,603,501,247 instructions              #    0.50  insns per cycle
                                             #    1.48  stalled cycles per insn
       484,357,498 branches                  #  283.455 M/sec
         6,388,934 branch-misses             #    1.32% of all branches

        0.154822978  seconds time elapsed

 *
 * Copyright (C) 2008-2011, Red Hat Inc, Ingo Molnar <[email protected]>
 *
 * Improvements and fixes by:
 *
 *   Arjan van de Ven <[email protected]>
 *   Yanmin Zhang <[email protected]>
 *   Wu Fengguang <[email protected]>
 *   Mike Galbraith <[email protected]>
 *   Paul Mackerras <[email protected]>
 *   Jaswinder Singh Rajput <[email protected]>
 *
 * Released under the GPL v2. (and only v2, not any later version)
 */

#include "perf.h"
#include "builtin.h"
#include "util/util.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include "util/event.h"
#include "util/evlist.h"
#include "util/evsel.h"
#include "util/debug.h"
#include "util/color.h"
#include "util/stat.h"
#include "util/header.h"
#include "util/cpumap.h"
#include "util/thread.h"
#include "util/thread_map.h"

#include <sys/prctl.h>
#include <locale.h>

#define DEFAULT_SEPARATOR   " "
#define CNTR_NOT_SUPPORTED  "<not supported>"
#define CNTR_NOT_COUNTED    "<not counted>"

static struct perf_evlist   *evsel_list;

static struct perf_target   target = {
    .uid    = UINT_MAX,
};

static int          run_count           =  1;
static bool         no_inherit          = false;
static bool         scale               =  true;
static bool         no_aggr             = false;
static pid_t            child_pid           = -1;
static bool         null_run            =  false;
static int          detailed_run            =  0;
static bool         big_num             =  true;
static int          big_num_opt         =  -1;
static const char       *csv_sep            = NULL;
static bool         csv_output          = false;
static bool         group               = false;
static FILE         *output             = NULL;

static volatile int done = 0;

struct perf_stat {
    struct stats      res_stats[3];
};

static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel)
{
    evsel->priv = zalloc(sizeof(struct perf_stat));
    return evsel->priv == NULL ? -ENOMEM : 0;
}

static void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
{
    free(evsel->priv);
    evsel->priv = NULL;
}

static inline struct cpu_map *perf_evsel__cpus(struct perf_evsel *evsel)
{
    return (evsel->cpus && !target.cpu_list) ? evsel->cpus : evsel_list->cpus;
}

static inline int perf_evsel__nr_cpus(struct perf_evsel *evsel)
{
    return perf_evsel__cpus(evsel)->nr;
}

static struct stats runtime_nsecs_stats[MAX_NR_CPUS];
static struct stats runtime_cycles_stats[MAX_NR_CPUS];
static struct stats runtime_stalled_cycles_front_stats[MAX_NR_CPUS];
static struct stats runtime_stalled_cycles_back_stats[MAX_NR_CPUS];
static struct stats runtime_branches_stats[MAX_NR_CPUS];
static struct stats runtime_cacherefs_stats[MAX_NR_CPUS];
static struct stats runtime_l1_dcache_stats[MAX_NR_CPUS];
static struct stats runtime_l1_icache_stats[MAX_NR_CPUS];
static struct stats runtime_ll_cache_stats[MAX_NR_CPUS];
static struct stats runtime_itlb_cache_stats[MAX_NR_CPUS];
static struct stats runtime_dtlb_cache_stats[MAX_NR_CPUS];
static struct stats walltime_nsecs_stats;

static int create_perf_stat_counter(struct perf_evsel *evsel,
                    struct perf_evsel *first)
{
    struct perf_event_attr *attr = &evsel->attr;
    bool exclude_guest_missing = false;
    int ret;

    if (scale)
        attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
                    PERF_FORMAT_TOTAL_TIME_RUNNING;

    attr->inherit = !no_inherit;

retry:
    if (exclude_guest_missing)
        evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;

    if (perf_target__has_cpu(&target)) {
        ret = perf_evsel__open_per_cpu(evsel, perf_evsel__cpus(evsel));
        if (ret)
            goto check_ret;
        return 0;
    }

    if (!perf_target__has_task(&target) && (!group || evsel == first)) {
        attr->disabled = 1;
        attr->enable_on_exec = 1;
    }

    ret = perf_evsel__open_per_thread(evsel, evsel_list->threads);
    if (!ret)
        return 0;
    /* fall through */
check_ret:
    if (ret && errno == EINVAL) {
        if (!exclude_guest_missing &&
            (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
            pr_debug("Old kernel, cannot exclude "
                 "guest or host samples.\n");
            exclude_guest_missing = true;
            goto retry;
        }
    }
    return ret;
}

/*
 * Does the counter have nsecs as a unit?
 */
static inline int nsec_counter(struct perf_evsel *evsel)
{
    if (perf_evsel__match(evsel, SOFTWARE, SW_CPU_CLOCK) ||
        perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK))
        return 1;

    return 0;
}

/*
 * Update various tracking values we maintain to print
 * more semantic information such as miss/hit ratios,
 * instruction rates, etc:
 */
static void update_shadow_stats(struct perf_evsel *counter, u64 *count)
{
    if (perf_evsel__match(counter, SOFTWARE, SW_TASK_CLOCK))
        update_stats(&runtime_nsecs_stats[0], count[0]);
    else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
        update_stats(&runtime_cycles_stats[0], count[0]);
    else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_FRONTEND))
        update_stats(&runtime_stalled_cycles_front_stats[0], count[0]);
    else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_BACKEND))
        update_stats(&runtime_stalled_cycles_back_stats[0], count[0]);
    else if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
        update_stats(&runtime_branches_stats[0], count[0]);
    else if (perf_evsel__match(counter, HARDWARE, HW_CACHE_REFERENCES))
        update_stats(&runtime_cacherefs_stats[0], count[0]);
    else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_L1D))
        update_stats(&runtime_l1_dcache_stats[0], count[0]);
    else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_L1I))
        update_stats(&runtime_l1_icache_stats[0], count[0]);
    else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_LL))
        update_stats(&runtime_ll_cache_stats[0], count[0]);
    else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_DTLB))
        update_stats(&runtime_dtlb_cache_stats[0], count[0]);
    else if (perf_evsel__match(counter, HW_CACHE, HW_CACHE_ITLB))
        update_stats(&runtime_itlb_cache_stats[0], count[0]);
}

/*
 * Read out the results of a single counter:
 * aggregate counts across CPUs in system-wide mode
 */
static int read_counter_aggr(struct perf_evsel *counter)
{
    struct perf_stat *ps = counter->priv;
    u64 *count = counter->counts->aggr.values;
    int i;

    if (__perf_evsel__read(counter, perf_evsel__nr_cpus(counter),
                   evsel_list->threads->nr, scale) < 0)
        return -1;

    for (i = 0; i < 3; i++)
        update_stats(&ps->res_stats[i], count[i]);

    if (verbose) {
        fprintf(output, "%s: %" PRIu64 " %" PRIu64 " %" PRIu64 "\n",
            perf_evsel__name(counter), count[0], count[1], count[2]);
    }

    /*
     * Save the full runtime - to allow normalization during printout:
     */
    update_shadow_stats(counter, count);

    return 0;
}

/*
 * Read out the results of a single counter:
 * do not aggregate counts across CPUs in system-wide mode
 */
static int read_counter(struct perf_evsel *counter)
{
    u64 *count;
    int cpu;

    for (cpu = 0; cpu < perf_evsel__nr_cpus(counter); cpu++) {
        if (__perf_evsel__read_on_cpu(counter, cpu, 0, scale) < 0)
            return -1;

        count = counter->counts->cpu[cpu].values;

        update_shadow_stats(counter, count);
    }

    return 0;
}

static int run_perf_stat(int argc __maybe_unused, const char **argv)
{
    unsigned long long t0, t1;
    struct perf_evsel *counter, *first;
    int status = 0;
    int child_ready_pipe[2], go_pipe[2];
    const bool forks = (argc > 0);
    char buf;

    if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
        perror("failed to create pipes");
        return -1;
    }

    if (forks) {
        if ((child_pid = fork()) < 0)
            perror("failed to fork");

        if (!child_pid) {
            close(child_ready_pipe[0]);
            close(go_pipe[1]);
            fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);

            /*
             * Do a dummy execvp to get the PLT entry resolved,
             * so we avoid the resolver overhead on the real
             * execvp call.
             */
            execvp("", (char **)argv);

            /*
             * Tell the parent we're ready to go
             */
            close(child_ready_pipe[1]);

            /*
             * Wait until the parent tells us to go.
             */
            if (read(go_pipe[0], &buf, 1) == -1)
                perror("unable to read pipe");

            execvp(argv[0], (char **)argv);

            perror(argv[0]);
            exit(-1);
        }

        if (perf_target__none(&target))
            evsel_list->threads->map[0] = child_pid;

        /*
         * Wait for the child to be ready to exec.
         */
        close(child_ready_pipe[1]);
        close(go_pipe[0]);
        if (read(child_ready_pipe[0], &buf, 1) == -1)
            perror("unable to read pipe");
        close(child_ready_pipe[0]);
    }

    if (group)
        perf_evlist__set_leader(evsel_list);

    first = perf_evlist__first(evsel_list);

    list_for_each_entry(counter, &evsel_list->entries, node) {
        if (create_perf_stat_counter(counter, first) < 0) {
            /*
             * PPC returns ENXIO for HW counters until 2.6.37
             * (behavior changed with commit b0a873e).
             */
            if (errno == EINVAL || errno == ENOSYS ||
                errno == ENOENT || errno == EOPNOTSUPP ||
                errno == ENXIO) {
                if (verbose)
                    ui__warning("%s event is not supported by the kernel.\n",
                            perf_evsel__name(counter));
                counter->supported = false;
                continue;
            }

            if (errno == EPERM || errno == EACCES) {
                error("You may not have permission to collect %sstats.\n"
                      "\t Consider tweaking"
                      " /proc/sys/kernel/perf_event_paranoid or running as root.",
                      target.system_wide ? "system-wide " : "");
            } else {
                error("open_counter returned with %d (%s). "
                      "/bin/dmesg may provide additional information.\n",
                       errno, strerror(errno));
            }
            if (child_pid != -1)
                kill(child_pid, SIGTERM);

            pr_err("Not all events could be opened.\n");
            return -1;
        }
        counter->supported = true;
    }

    if (perf_evlist__apply_filters(evsel_list)) {
        error("failed to set filter with %d (%s)\n", errno,
            strerror(errno));
        return -1;
    }

    /*
     * Enable counters and exec the command:
     */
    t0 = rdclock();

    if (forks) {
        close(go_pipe[1]);
        wait(&status);
        if (WIFSIGNALED(status))
            psignal(WTERMSIG(status), argv[0]);
    } else {
        while(!done) sleep(1);
    }

    t1 = rdclock();

    update_stats(&walltime_nsecs_stats, t1 - t0);

    if (no_aggr) {
        list_for_each_entry(counter, &evsel_list->entries, node) {
            read_counter(counter);
            perf_evsel__close_fd(counter, perf_evsel__nr_cpus(counter), 1);
        }
    } else {
        list_for_each_entry(counter, &evsel_list->entries, node) {
            read_counter_aggr(counter);
            perf_evsel__close_fd(counter, perf_evsel__nr_cpus(counter),
                         evsel_list->threads->nr);
        }
    }

    return WEXITSTATUS(status);
}

static void print_noise_pct(double total, double avg)
{
    double pct = rel_stddev_stats(total, avg);

    if (csv_output)
        fprintf(output, "%s%.2f%%", csv_sep, pct);
    else if (pct)
        fprintf(output, "  ( +-%6.2f%% )", pct);
}

static void print_noise(struct perf_evsel *evsel, double avg)
{
    struct perf_stat *ps;

    if (run_count == 1)
        return;

    ps = evsel->priv;
    print_noise_pct(stddev_stats(&ps->res_stats[0]), avg);
}

static void nsec_printout(int cpu, struct perf_evsel *evsel, double avg)
{
    double msecs = avg / 1e6;
    char cpustr[16] = { '\0', };
    const char *fmt = csv_output ? "%s%.6f%s%s" : "%s%18.6f%s%-25s";

    if (no_aggr)
        sprintf(cpustr, "CPU%*d%s",
            csv_output ? 0 : -4,
            perf_evsel__cpus(evsel)->map[cpu], csv_sep);

    fprintf(output, fmt, cpustr, msecs, csv_sep, perf_evsel__name(evsel));

    if (evsel->cgrp)
        fprintf(output, "%s%s", csv_sep, evsel->cgrp->name);

    if (csv_output)
        return;

    if (perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK))
        fprintf(output, " # %8.3f CPUs utilized          ",
            avg / avg_stats(&walltime_nsecs_stats));
    else
        fprintf(output, "                                   ");
}

/* used for get_ratio_color() */
enum grc_type {
    GRC_STALLED_CYCLES_FE,
    GRC_STALLED_CYCLES_BE,
    GRC_CACHE_MISSES,
    GRC_MAX_NR
};

static const char *get_ratio_color(enum grc_type type, double ratio)
{
    static const double grc_table[GRC_MAX_NR][3] = {
        [GRC_STALLED_CYCLES_FE] = { 50.0, 30.0, 10.0 },
        [GRC_STALLED_CYCLES_BE] = { 75.0, 50.0, 20.0 },
        [GRC_CACHE_MISSES]  = { 20.0, 10.0, 5.0 },
    };
    const char *color = PERF_COLOR_NORMAL;

    if (ratio > grc_table[type][0])
        color = PERF_COLOR_RED;
    else if (ratio > grc_table[type][1])
        color = PERF_COLOR_MAGENTA;
    else if (ratio > grc_table[type][2])
        color = PERF_COLOR_YELLOW;

    return color;
}

static void print_stalled_cycles_frontend(int cpu,
                      struct perf_evsel *evsel
                      __maybe_unused, double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_cycles_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_STALLED_CYCLES_FE, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " frontend cycles idle   ");
}

static void print_stalled_cycles_backend(int cpu,
                     struct perf_evsel *evsel
                     __maybe_unused, double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_cycles_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_STALLED_CYCLES_BE, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " backend  cycles idle   ");
}

static void print_branch_misses(int cpu,
                struct perf_evsel *evsel __maybe_unused,
                double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_branches_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_CACHE_MISSES, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " of all branches        ");
}

static void print_l1_dcache_misses(int cpu,
                   struct perf_evsel *evsel __maybe_unused,
                   double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_l1_dcache_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_CACHE_MISSES, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " of all L1-dcache hits  ");
}

static void print_l1_icache_misses(int cpu,
                   struct perf_evsel *evsel __maybe_unused,
                   double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_l1_icache_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_CACHE_MISSES, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " of all L1-icache hits  ");
}

static void print_dtlb_cache_misses(int cpu,
                    struct perf_evsel *evsel __maybe_unused,
                    double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_dtlb_cache_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_CACHE_MISSES, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " of all dTLB cache hits ");
}

static void print_itlb_cache_misses(int cpu,
                    struct perf_evsel *evsel __maybe_unused,
                    double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_itlb_cache_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_CACHE_MISSES, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " of all iTLB cache hits ");
}

static void print_ll_cache_misses(int cpu,
                  struct perf_evsel *evsel __maybe_unused,
                  double avg)
{
    double total, ratio = 0.0;
    const char *color;

    total = avg_stats(&runtime_ll_cache_stats[cpu]);

    if (total)
        ratio = avg / total * 100.0;

    color = get_ratio_color(GRC_CACHE_MISSES, ratio);

    fprintf(output, " #  ");
    color_fprintf(output, color, "%6.2f%%", ratio);
    fprintf(output, " of all LL-cache hits   ");
}

static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)
{
    double total, ratio = 0.0;
    char cpustr[16] = { '\0', };
    const char *fmt;

    if (csv_output)
        fmt = "%s%.0f%s%s";
    else if (big_num)
        fmt = "%s%'18.0f%s%-25s";
    else
        fmt = "%s%18.0f%s%-25s";

    if (no_aggr)
        sprintf(cpustr, "CPU%*d%s",
            csv_output ? 0 : -4,
            perf_evsel__cpus(evsel)->map[cpu], csv_sep);
    else
        cpu = 0;

    fprintf(output, fmt, cpustr, avg, csv_sep, perf_evsel__name(evsel));

    if (evsel->cgrp)
        fprintf(output, "%s%s", csv_sep, evsel->cgrp->name);

    if (csv_output)
        return;

    if (perf_evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS)) {
        total = avg_stats(&runtime_cycles_stats[cpu]);

        if (total)
            ratio = avg / total;

        fprintf(output, " #   %5.2f  insns per cycle        ", ratio);

        total = avg_stats(&runtime_stalled_cycles_front_stats[cpu]);
        total = max(total, avg_stats(&runtime_stalled_cycles_back_stats[cpu]));

        if (total && avg) {
            ratio = total / avg;
            fprintf(output, "\n                                             #   %5.2f  stalled cycles per insn", ratio);
        }

    } else if (perf_evsel__match(evsel, HARDWARE, HW_BRANCH_MISSES) &&
            runtime_branches_stats[cpu].n != 0) {
        print_branch_misses(cpu, evsel, avg);
    } else if (
        evsel->attr.type == PERF_TYPE_HW_CACHE &&
        evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_L1D |
                    ((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
                    ((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
            runtime_l1_dcache_stats[cpu].n != 0) {
        print_l1_dcache_misses(cpu, evsel, avg);
    } else if (
        evsel->attr.type == PERF_TYPE_HW_CACHE &&
        evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_L1I |
                    ((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
                    ((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
            runtime_l1_icache_stats[cpu].n != 0) {
        print_l1_icache_misses(cpu, evsel, avg);
    } else if (
        evsel->attr.type == PERF_TYPE_HW_CACHE &&
        evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_DTLB |
                    ((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
                    ((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
            runtime_dtlb_cache_stats[cpu].n != 0) {
        print_dtlb_cache_misses(cpu, evsel, avg);
    } else if (
        evsel->attr.type == PERF_TYPE_HW_CACHE &&
        evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_ITLB |
                    ((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
                    ((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
            runtime_itlb_cache_stats[cpu].n != 0) {
        print_itlb_cache_misses(cpu, evsel, avg);
    } else if (
        evsel->attr.type == PERF_TYPE_HW_CACHE &&
        evsel->attr.config ==  ( PERF_COUNT_HW_CACHE_LL |
                    ((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
                    ((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16)) &&
            runtime_ll_cache_stats[cpu].n != 0) {
        print_ll_cache_misses(cpu, evsel, avg);
    } else if (perf_evsel__match(evsel, HARDWARE, HW_CACHE_MISSES) &&
            runtime_cacherefs_stats[cpu].n != 0) {
        total = avg_stats(&runtime_cacherefs_stats[cpu]);

        if (total)
            ratio = avg * 100 / total;

        fprintf(output, " # %8.3f %% of all cache refs    ", ratio);

    } else if (perf_evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES_FRONTEND)) {
        print_stalled_cycles_frontend(cpu, evsel, avg);
    } else if (perf_evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES_BACKEND)) {
        print_stalled_cycles_backend(cpu, evsel, avg);
    } else if (perf_evsel__match(evsel, HARDWARE, HW_CPU_CYCLES)) {
        total = avg_stats(&runtime_nsecs_stats[cpu]);

        if (total)
            ratio = 1.0 * avg / total;

        fprintf(output, " # %8.3f GHz                    ", ratio);
    } else if (runtime_nsecs_stats[cpu].n != 0) {
        char unit = 'M';

        total = avg_stats(&runtime_nsecs_stats[cpu]);

        if (total)
            ratio = 1000.0 * avg / total;
        if (ratio < 0.001) {
            ratio *= 1000;
            unit = 'K';
        }

        fprintf(output, " # %8.3f %c/sec                  ", ratio, unit);
    } else {
        fprintf(output, "                                   ");
    }
}

/*
 * Print out the results of a single counter:
 * aggregated counts in system-wide mode
 */
static void print_counter_aggr(struct perf_evsel *counter)
{
    struct perf_stat *ps = counter->priv;
    double avg = avg_stats(&ps->res_stats[0]);
    int scaled = counter->counts->scaled;

    if (scaled == -1) {
        fprintf(output, "%*s%s%*s",
            csv_output ? 0 : 18,
            counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
            csv_sep,
            csv_output ? 0 : -24,
            perf_evsel__name(counter));

        if (counter->cgrp)
            fprintf(output, "%s%s", csv_sep, counter->cgrp->name);

        fputc('\n', output);
        return;
    }

    if (nsec_counter(counter))
        nsec_printout(-1, counter, avg);
    else
        abs_printout(-1, counter, avg);

    print_noise(counter, avg);

    if (csv_output) {
        fputc('\n', output);
        return;
    }

    if (scaled) {
        double avg_enabled, avg_running;

        avg_enabled = avg_stats(&ps->res_stats[1]);
        avg_running = avg_stats(&ps->res_stats[2]);

        fprintf(output, " [%5.2f%%]", 100 * avg_running / avg_enabled);
    }
    fprintf(output, "\n");
}

/*
 * Print out the results of a single counter:
 * does not use aggregated count in system-wide
 */
static void print_counter(struct perf_evsel *counter)
{
    u64 ena, run, val;
    int cpu;

    for (cpu = 0; cpu < perf_evsel__nr_cpus(counter); cpu++) {
        val = counter->counts->cpu[cpu].val;
        ena = counter->counts->cpu[cpu].ena;
        run = counter->counts->cpu[cpu].run;
        if (run == 0 || ena == 0) {
            fprintf(output, "CPU%*d%s%*s%s%*s",
                csv_output ? 0 : -4,
                perf_evsel__cpus(counter)->map[cpu], csv_sep,
                csv_output ? 0 : 18,
                counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
                csv_sep,
                csv_output ? 0 : -24,
                perf_evsel__name(counter));

            if (counter->cgrp)
                fprintf(output, "%s%s",
                    csv_sep, counter->cgrp->name);

            fputc('\n', output);
            continue;
        }

        if (nsec_counter(counter))
            nsec_printout(cpu, counter, val);
        else
            abs_printout(cpu, counter, val);

        if (!csv_output) {
            print_noise(counter, 1.0);

            if (run != ena)
                fprintf(output, "  (%.2f%%)",
                    100.0 * run / ena);
        }
        fputc('\n', output);
    }
}

static void print_stat(int argc, const char **argv)
{
    struct perf_evsel *counter;
    int i;

    fflush(stdout);

    if (!csv_output) {
        fprintf(output, "\n");
        fprintf(output, " Performance counter stats for ");
        if (!perf_target__has_task(&target)) {
            fprintf(output, "\'%s", argv[0]);
            for (i = 1; i < argc; i++)
                fprintf(output, " %s", argv[i]);
        } else if (target.pid)
            fprintf(output, "process id \'%s", target.pid);
        else
            fprintf(output, "thread id \'%s", target.tid);

        fprintf(output, "\'");
        if (run_count > 1)
            fprintf(output, " (%d runs)", run_count);
        fprintf(output, ":\n\n");
    }

    if (no_aggr) {
        list_for_each_entry(counter, &evsel_list->entries, node)
            print_counter(counter);
    } else {
        list_for_each_entry(counter, &evsel_list->entries, node)
            print_counter_aggr(counter);
    }

    if (!csv_output) {
        if (!null_run)
            fprintf(output, "\n");
        fprintf(output, " %17.9f seconds time elapsed",
                avg_stats(&walltime_nsecs_stats)/1e9);
        if (run_count > 1) {
            fprintf(output, "                                        ");
            print_noise_pct(stddev_stats(&walltime_nsecs_stats),
                    avg_stats(&walltime_nsecs_stats));
        }
        fprintf(output, "\n\n");
    }
}

static volatile int signr = -1;

static void skip_signal(int signo)
{
    if(child_pid == -1)
        done = 1;

    signr = signo;
}

static void sig_atexit(void)
{
    if (child_pid != -1)
        kill(child_pid, SIGTERM);

    if (signr == -1)
        return;

    signal(signr, SIG_DFL);
    kill(getpid(), signr);
}

static int stat__set_big_num(const struct option *opt __maybe_unused,
                 const char *s __maybe_unused, int unset)
{
    big_num_opt = unset ? 0 : 1;
    return 0;
}

/*
 * Add default attributes, if there were no attributes specified or
 * if -d/--detailed, -d -d or -d -d -d is used:
 */
static int add_default_attributes(void)
{
    struct perf_event_attr default_attrs[] = {

  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK      },
  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES    },
  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS      },
  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS     },

  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES      },
  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_FRONTEND },
  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_STALLED_CYCLES_BACKEND  },
  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS        },
  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_MISSES       },

};

/*
 * Detailed stats (-d), covering the L1 and last level data caches:
 */
    struct perf_event_attr detailed_attrs[] = {

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_L1D        <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_ACCESS  << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_L1D        <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_MISS    << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_LL         <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_ACCESS  << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_LL         <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_MISS    << 16)              },
};

/*
 * Very detailed stats (-d -d), covering the instruction cache and the TLB caches:
 */
    struct perf_event_attr very_detailed_attrs[] = {

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_L1I        <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_ACCESS  << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_L1I        <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_MISS    << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_DTLB       <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_ACCESS  << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_DTLB       <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_MISS    << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_ITLB       <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_ACCESS  << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_ITLB       <<  0  |
    (PERF_COUNT_HW_CACHE_OP_READ        <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_MISS    << 16)              },

};

/*
 * Very, very detailed stats (-d -d -d), adding prefetch events:
 */
    struct perf_event_attr very_very_detailed_attrs[] = {

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_L1D        <<  0  |
    (PERF_COUNT_HW_CACHE_OP_PREFETCH    <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_ACCESS  << 16)              },

  { .type = PERF_TYPE_HW_CACHE,
    .config =
     PERF_COUNT_HW_CACHE_L1D        <<  0  |
    (PERF_COUNT_HW_CACHE_OP_PREFETCH    <<  8) |
    (PERF_COUNT_HW_CACHE_RESULT_MISS    << 16)              },
};

    /* Set attrs if no event is selected and !null_run: */
    if (null_run)
        return 0;

    if (!evsel_list->nr_entries) {
        if (perf_evlist__add_default_attrs(evsel_list, default_attrs) < 0)
            return -1;
    }

    /* Detailed events get appended to the event list: */

    if (detailed_run <  1)
        return 0;

    /* Append detailed run extra attributes: */
    if (perf_evlist__add_default_attrs(evsel_list, detailed_attrs) < 0)
        return -1;

    if (detailed_run < 2)
        return 0;

    /* Append very detailed run extra attributes: */
    if (perf_evlist__add_default_attrs(evsel_list, very_detailed_attrs) < 0)
        return -1;

    if (detailed_run < 3)
        return 0;

    /* Append very, very detailed run extra attributes: */
    return perf_evlist__add_default_attrs(evsel_list, very_very_detailed_attrs);
}

int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
{
    bool append_file = false,
         sync_run = false;
    int output_fd = 0;
    const char *output_name = NULL;
    const struct option options[] = {
    OPT_CALLBACK('e', "event", &evsel_list, "event",
             "event selector. use 'perf list' to list available events",
             parse_events_option),
    OPT_CALLBACK(0, "filter", &evsel_list, "filter",
             "event filter", parse_filter),
    OPT_BOOLEAN('i', "no-inherit", &no_inherit,
            "child tasks do not inherit counters"),
    OPT_STRING('p', "pid", &target.pid, "pid",
           "stat events on existing process id"),
    OPT_STRING('t', "tid", &target.tid, "tid",
           "stat events on existing thread id"),
    OPT_BOOLEAN('a', "all-cpus", &target.system_wide,
            "system-wide collection from all CPUs"),
    OPT_BOOLEAN('g', "group", &group,
            "put the counters into a counter group"),
    OPT_BOOLEAN('c', "scale", &scale, "scale/normalize counters"),
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show counter open errors, etc)"),
    OPT_INTEGER('r', "repeat", &run_count,
            "repeat command and print average + stddev (max: 100)"),
    OPT_BOOLEAN('n', "null", &null_run,
            "null run - dont start any counters"),
    OPT_INCR('d', "detailed", &detailed_run,
            "detailed run - start a lot of events"),
    OPT_BOOLEAN('S', "sync", &sync_run,
            "call sync() before starting a run"),
    OPT_CALLBACK_NOOPT('B', "big-num", NULL, NULL, 
               "print large numbers with thousands\' separators",
               stat__set_big_num),
    OPT_STRING('C', "cpu", &target.cpu_list, "cpu",
            "list of cpus to monitor in system-wide"),
    OPT_BOOLEAN('A', "no-aggr", &no_aggr, "disable CPU count aggregation"),
    OPT_STRING('x', "field-separator", &csv_sep, "separator",
           "print counts with custom separator"),
    OPT_CALLBACK('G', "cgroup", &evsel_list, "name",
             "monitor event in cgroup name only", parse_cgroups),
    OPT_STRING('o', "output", &output_name, "file", "output file name"),
    OPT_BOOLEAN(0, "append", &append_file, "append to the output file"),
    OPT_INTEGER(0, "log-fd", &output_fd,
            "log output to fd, instead of stderr"),
    OPT_END()
    };
    const char * const stat_usage[] = {
        "perf stat [<options>] [<command>]",
        NULL
    };
    struct perf_evsel *pos;
    int status = -ENOMEM, run_idx;
    const char *mode;

    setlocale(LC_ALL, "");

    evsel_list = perf_evlist__new(NULL, NULL);
    if (evsel_list == NULL)
        return -ENOMEM;

    argc = parse_options(argc, argv, options, stat_usage,
        PARSE_OPT_STOP_AT_NON_OPTION);

    output = stderr;
    if (output_name && strcmp(output_name, "-"))
        output = NULL;

    if (output_name && output_fd) {
        fprintf(stderr, "cannot use both --output and --log-fd\n");
        usage_with_options(stat_usage, options);
    }

    if (output_fd < 0) {
        fprintf(stderr, "argument to --log-fd must be a > 0\n");
        usage_with_options(stat_usage, options);
    }

    if (!output) {
        struct timespec tm;
        mode = append_file ? "a" : "w";

        output = fopen(output_name, mode);
        if (!output) {
            perror("failed to create output file");
            return -1;
        }
        clock_gettime(CLOCK_REALTIME, &tm);
        fprintf(output, "# started on %s\n", ctime(&tm.tv_sec));
    } else if (output_fd > 0) {
        mode = append_file ? "a" : "w";
        output = fdopen(output_fd, mode);
        if (!output) {
            perror("Failed opening logfd");
            return -errno;
        }
    }

    if (csv_sep) {
        csv_output = true;
        if (!strcmp(csv_sep, "\\t"))
            csv_sep = "\t";
    } else
        csv_sep = DEFAULT_SEPARATOR;

    /*
     * let the spreadsheet do the pretty-printing
     */
    if (csv_output) {
        /* User explicitly passed -B? */
        if (big_num_opt == 1) {
            fprintf(stderr, "-B option not supported with -x\n");
            usage_with_options(stat_usage, options);
        } else /* Nope, so disable big number formatting */
            big_num = false;
    } else if (big_num_opt == 0) /* User passed --no-big-num */
        big_num = false;

    if (!argc && !perf_target__has_task(&target))
        usage_with_options(stat_usage, options);
    if (run_count <= 0)
        usage_with_options(stat_usage, options);

    /* no_aggr, cgroup are for system-wide only */
    if ((no_aggr || nr_cgroups) && !perf_target__has_cpu(&target)) {
        fprintf(stderr, "both cgroup and no-aggregation "
            "modes only available in system-wide mode\n");

        usage_with_options(stat_usage, options);
    }

    if (add_default_attributes())
        goto out;

    perf_target__validate(&target);

    if (perf_evlist__create_maps(evsel_list, &target) < 0) {
        if (perf_target__has_task(&target))
            pr_err("Problems finding threads of monitor\n");
        if (perf_target__has_cpu(&target))
            perror("failed to parse CPUs map");

        usage_with_options(stat_usage, options);
        return -1;
    }

    list_for_each_entry(pos, &evsel_list->entries, node) {
        if (perf_evsel__alloc_stat_priv(pos) < 0 ||
            perf_evsel__alloc_counts(pos, perf_evsel__nr_cpus(pos)) < 0)
            goto out_free_fd;
    }

    /*
     * We dont want to block the signals - that would cause
     * child tasks to inherit that and Ctrl-C would not work.
     * What we want is for Ctrl-C to work in the exec()-ed
     * task, but being ignored by perf stat itself:
     */
    atexit(sig_atexit);
    signal(SIGINT,  skip_signal);
    signal(SIGALRM, skip_signal);
    signal(SIGABRT, skip_signal);

    status = 0;
    for (run_idx = 0; run_idx < run_count; run_idx++) {
        if (run_count != 1 && verbose)
            fprintf(output, "[ perf stat: executing run #%d ... ]\n",
                run_idx + 1);

        if (sync_run)
            sync();

        status = run_perf_stat(argc, argv);
    }

    if (status != -1)
        print_stat(argc, argv);
out_free_fd:
    list_for_each_entry(pos, &evsel_list->entries, node)
        perf_evsel__free_stat_priv(pos);
    perf_evlist__delete_maps(evsel_list);
out:
    perf_evlist__delete(evsel_list);
    return status;
}