--- /dev/null
+/*
+ * mem-memset.c
+ *
+ * memset: Simple memory set in various ways
+ *
+ * Trivial clone of mem-memcpy.c.
+ */
+#include <ctype.h>
+
+#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 bool            use_clock;
+static int             clock_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 copy. "
+                   "available unit: B, MB, GB (upper and lower)"),
+       OPT_STRING('r', "routine", &routine, "default",
+                   "Specify routine to copy"),
+       OPT_BOOLEAN('c', "clock", &use_clock,
+                   "Use CPU clock 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 clock_attr = {
+       .type           = PERF_TYPE_HARDWARE,
+       .config         = PERF_COUNT_HW_CPU_CYCLES
+};
+
+static void init_clock(void)
+{
+       clock_fd = sys_perf_event_open(&clock_attr, getpid(), -1, -1, 0);
+
+       if (clock_fd < 0 && errno == ENOSYS)
+               die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
+       else
+               BUG_ON(clock_fd < 0);
+}
+
+static u64 get_clock(void)
+{
+       int ret;
+       u64 clk;
+
+       ret = read(clock_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_clock(memset_t fn, size_t len, bool prefault)
+{
+       u64 clock_start = 0ULL, clock_end = 0ULL;
+       void *dst = NULL;
+
+       alloc_mem(&dst, len);
+
+       if (prefault)
+               fn(dst, -1, len);
+
+       clock_start = get_clock();
+       fn(dst, 0, len);
+       clock_end = get_clock();
+
+       free(dst);
+       return clock_end - clock_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;
+
+       alloc_mem(&dst, len);
+
+       if (prefault)
+               fn(dst, -1, len);
+
+       BUG_ON(gettimeofday(&tv_start, NULL));
+       fn(dst, 0, 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 __used)
+{
+       int i;
+       size_t len;
+       double result_bps[2];
+       u64 result_clock[2];
+
+       argc = parse_options(argc, argv, options,
+                            bench_mem_memset_usage, 0);
+
+       if (use_clock)
+               init_clock();
+
+       len = (size_t)perf_atoll((char *)length_str);
+
+       result_clock[0] = result_clock[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_clock) {
+                       result_clock[0] =
+                               do_memset_clock(routines[i].fn, len, false);
+                       result_clock[1] =
+                               do_memset_clock(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_clock) {
+                       result_clock[pf] =
+                               do_memset_clock(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_clock) {
+                               printf(" %14lf Clock/Byte\n",
+                                       (double)result_clock[0]
+                                       / (double)len);
+                               printf(" %14lf Clock/Byte (with prefault)\n ",
+                                       (double)result_clock[1]
+                                       / (double)len);
+                       } else {
+                               print_bps(result_bps[0]);
+                               printf("\n");
+                               print_bps(result_bps[1]);
+                               printf(" (with prefault)\n");
+                       }
+               } else {
+                       if (use_clock) {
+                               printf(" %14lf Clock/Byte",
+                                       (double)result_clock[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_clock) {
+                               printf("%lf %lf\n",
+                                       (double)result_clock[0] / (double)len,
+                                       (double)result_clock[1] / (double)len);
+                       } else {
+                               printf("%lf %lf\n",
+                                       result_bps[0], result_bps[1]);
+                       }
+               } else {
+                       if (use_clock) {
+                               printf("%lf\n", (double)result_clock[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;
+}