mem-memset.c

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/*
 * mem-memset.c
 *
 * memset: Simple memory set in various ways
 *
 * Trivial clone of mem-memcpy.c.
 */

#include "../perf.h"
#include "../util/util.h"
#include "../util/parse-options.h"
#include "../util/header.h"
#include "bench.h"
#include "mem-memset-arch.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <errno.h>

#define K 1024

static const char   *length_str = "1MB";
static const char   *routine    = "default";
static int      iterations  = 1;
static bool     use_cycle;
static int      cycle_fd;
static bool     only_prefault;
static bool     no_prefault;

static const struct option options[] = {
    OPT_STRING('l', "length", &length_str, "1MB",
            "Specify length of memory to set. "
            "Available units: B, KB, MB, GB and TB (upper and lower)"),
    OPT_STRING('r', "routine", &routine, "default",
            "Specify routine to set"),
    OPT_INTEGER('i', "iterations", &iterations,
            "repeat memset() invocation this number of times"),
    OPT_BOOLEAN('c', "cycle", &use_cycle,
            "Use cycles event instead of gettimeofday() for measuring"),
    OPT_BOOLEAN('o', "only-prefault", &only_prefault,
            "Show only the result with page faults before memset()"),
    OPT_BOOLEAN('n', "no-prefault", &no_prefault,
            "Show only the result without page faults before memset()"),
    OPT_END()
};

typedef void *(*memset_t)(void *, int, size_t);

struct routine {
    const char *name;
    const char *desc;
    memset_t fn;
};

static const struct routine routines[] = {
    { "default",
      "Default memset() provided by glibc",
      memset },
#ifdef ARCH_X86_64

#define MEMSET_FN(fn, name, desc) { name, desc, fn },
#include "mem-memset-x86-64-asm-def.h"
#undef MEMSET_FN

#endif

    { NULL,
      NULL,
      NULL   }
};

static const char * const bench_mem_memset_usage[] = {
    "perf bench mem memset <options>",
    NULL
};

static struct perf_event_attr cycle_attr = {
    .type       = PERF_TYPE_HARDWARE,
    .config     = PERF_COUNT_HW_CPU_CYCLES
};

static void init_cycle(void)
{
    cycle_fd = sys_perf_event_open(&cycle_attr, getpid(), -1, -1, 0);

    if (cycle_fd < 0 && errno == ENOSYS)
        die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
    else
        BUG_ON(cycle_fd < 0);
}

static u64 get_cycle(void)
{
    int ret;
    u64 clk;

    ret = read(cycle_fd, &clk, sizeof(u64));
    BUG_ON(ret != sizeof(u64));

    return clk;
}

static double timeval2double(struct timeval *ts)
{
    return (double)ts->tv_sec +
        (double)ts->tv_usec / (double)1000000;
}

static void alloc_mem(void **dst, size_t length)
{
    *dst = zalloc(length);
    if (!dst)
        die("memory allocation failed - maybe length is too large?\n");
}

static u64 do_memset_cycle(memset_t fn, size_t len, bool prefault)
{
    u64 cycle_start = 0ULL, cycle_end = 0ULL;
    void *dst = NULL;
    int i;

    alloc_mem(&dst, len);

    if (prefault)
        fn(dst, -1, len);

    cycle_start = get_cycle();
    for (i = 0; i < iterations; ++i)
        fn(dst, i, len);
    cycle_end = get_cycle();

    free(dst);
    return cycle_end - cycle_start;
}

static double do_memset_gettimeofday(memset_t fn, size_t len, bool prefault)
{
    struct timeval tv_start, tv_end, tv_diff;
    void *dst = NULL;
    int i;

    alloc_mem(&dst, len);

    if (prefault)
        fn(dst, -1, len);

    BUG_ON(gettimeofday(&tv_start, NULL));
    for (i = 0; i < iterations; ++i)
        fn(dst, i, len);
    BUG_ON(gettimeofday(&tv_end, NULL));

    timersub(&tv_end, &tv_start, &tv_diff);

    free(dst);
    return (double)((double)len / timeval2double(&tv_diff));
}

#define pf (no_prefault ? 0 : 1)

#define print_bps(x) do {                   \
        if (x < K)                  \
            printf(" %14lf B/Sec", x);      \
        else if (x < K * K)             \
            printf(" %14lfd KB/Sec", x / K);    \
        else if (x < K * K * K)             \
            printf(" %14lf MB/Sec", x / K / K); \
        else                        \
            printf(" %14lf GB/Sec", x / K / K / K); \
    } while (0)

int bench_mem_memset(int argc, const char **argv,
             const char *prefix __maybe_unused)
{
    int i;
    size_t len;
    double result_bps[2];
    u64 result_cycle[2];

    argc = parse_options(argc, argv, options,
                 bench_mem_memset_usage, 0);

    if (use_cycle)
        init_cycle();

    len = (size_t)perf_atoll((char *)length_str);

    result_cycle[0] = result_cycle[1] = 0ULL;
    result_bps[0] = result_bps[1] = 0.0;

    if ((s64)len <= 0) {
        fprintf(stderr, "Invalid length:%s\n", length_str);
        return 1;
    }

    /* same to without specifying either of prefault and no-prefault */
    if (only_prefault && no_prefault)
        only_prefault = no_prefault = false;

    for (i = 0; routines[i].name; i++) {
        if (!strcmp(routines[i].name, routine))
            break;
    }
    if (!routines[i].name) {
        printf("Unknown routine:%s\n", routine);
        printf("Available routines...\n");
        for (i = 0; routines[i].name; i++) {
            printf("\t%s ... %s\n",
                   routines[i].name, routines[i].desc);
        }
        return 1;
    }

    if (bench_format == BENCH_FORMAT_DEFAULT)
        printf("# Copying %s Bytes ...\n\n", length_str);

    if (!only_prefault && !no_prefault) {
        /* show both of results */
        if (use_cycle) {
            result_cycle[0] =
                do_memset_cycle(routines[i].fn, len, false);
            result_cycle[1] =
                do_memset_cycle(routines[i].fn, len, true);
        } else {
            result_bps[0] =
                do_memset_gettimeofday(routines[i].fn,
                        len, false);
            result_bps[1] =
                do_memset_gettimeofday(routines[i].fn,
                        len, true);
        }
    } else {
        if (use_cycle) {
            result_cycle[pf] =
                do_memset_cycle(routines[i].fn,
                        len, only_prefault);
        } else {
            result_bps[pf] =
                do_memset_gettimeofday(routines[i].fn,
                        len, only_prefault);
        }
    }

    switch (bench_format) {
    case BENCH_FORMAT_DEFAULT:
        if (!only_prefault && !no_prefault) {
            if (use_cycle) {
                printf(" %14lf Cycle/Byte\n",
                    (double)result_cycle[0]
                    / (double)len);
                printf(" %14lf Cycle/Byte (with prefault)\n ",
                    (double)result_cycle[1]
                    / (double)len);
            } else {
                print_bps(result_bps[0]);
                printf("\n");
                print_bps(result_bps[1]);
                printf(" (with prefault)\n");
            }
        } else {
            if (use_cycle) {
                printf(" %14lf Cycle/Byte",
                    (double)result_cycle[pf]
                    / (double)len);
            } else
                print_bps(result_bps[pf]);

            printf("%s\n", only_prefault ? " (with prefault)" : "");
        }
        break;
    case BENCH_FORMAT_SIMPLE:
        if (!only_prefault && !no_prefault) {
            if (use_cycle) {
                printf("%lf %lf\n",
                    (double)result_cycle[0] / (double)len,
                    (double)result_cycle[1] / (double)len);
            } else {
                printf("%lf %lf\n",
                    result_bps[0], result_bps[1]);
            }
        } else {
            if (use_cycle) {
                printf("%lf\n", (double)result_cycle[pf]
                    / (double)len);
            } else
                printf("%lf\n", result_bps[pf]);
        }
        break;
    default:
        /* reaching this means there's some disaster: */
        die("unknown format: %d\n", bench_format);
        break;
    }

    return 0;
}