kernel-fxtec-pro1x/tools/perf/bench/mem-memcpy.c
Andi Kleen a198996c7a perf bench: Fix memcpy benchmark for large sizes
The glibc calloc() function has an optimization to not explicitely
memset() very large calloc allocations that just came from mmap(),
because they are known to be zero.

This could result in the perf memcpy benchmark reading only from
the zero page, which gives unrealistic results.

Always call memset explicitly on the source area to avoid this problem.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-pzz2qrdq9eymxda0y8yxdn33@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-22 12:41:56 -03:00

305 lines
6.8 KiB
C

/*
* mem-memcpy.c
*
* memcpy: Simple memory copy in various ways
*
* Written by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
*/
#include "../perf.h"
#include "../util/util.h"
#include "../util/parse-options.h"
#include "../util/header.h"
#include "bench.h"
#include "mem-memcpy-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 copy. "
"Available units: B, KB, MB, GB and TB (upper and lower)"),
OPT_STRING('r', "routine", &routine, "default",
"Specify routine to copy"),
OPT_INTEGER('i', "iterations", &iterations,
"repeat memcpy() 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 memcpy()"),
OPT_BOOLEAN('n', "no-prefault", &no_prefault,
"Show only the result without page faults before memcpy()"),
OPT_END()
};
typedef void *(*memcpy_t)(void *, const void *, size_t);
struct routine {
const char *name;
const char *desc;
memcpy_t fn;
};
struct routine routines[] = {
{ "default",
"Default memcpy() provided by glibc",
memcpy },
#ifdef ARCH_X86_64
#define MEMCPY_FN(fn, name, desc) { name, desc, fn },
#include "mem-memcpy-x86-64-asm-def.h"
#undef MEMCPY_FN
#endif
{ NULL,
NULL,
NULL }
};
static const char * const bench_mem_memcpy_usage[] = {
"perf bench mem memcpy <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, void **src, size_t length)
{
*dst = zalloc(length);
if (!*dst)
die("memory allocation failed - maybe length is too large?\n");
*src = zalloc(length);
if (!*src)
die("memory allocation failed - maybe length is too large?\n");
/* Make sure to always replace the zero pages even if MMAP_THRESH is crossed */
memset(*src, 0, length);
}
static u64 do_memcpy_cycle(memcpy_t fn, size_t len, bool prefault)
{
u64 cycle_start = 0ULL, cycle_end = 0ULL;
void *src = NULL, *dst = NULL;
int i;
alloc_mem(&src, &dst, len);
if (prefault)
fn(dst, src, len);
cycle_start = get_cycle();
for (i = 0; i < iterations; ++i)
fn(dst, src, len);
cycle_end = get_cycle();
free(src);
free(dst);
return cycle_end - cycle_start;
}
static double do_memcpy_gettimeofday(memcpy_t fn, size_t len, bool prefault)
{
struct timeval tv_start, tv_end, tv_diff;
void *src = NULL, *dst = NULL;
int i;
alloc_mem(&src, &dst, len);
if (prefault)
fn(dst, src, len);
BUG_ON(gettimeofday(&tv_start, NULL));
for (i = 0; i < iterations; ++i)
fn(dst, src, len);
BUG_ON(gettimeofday(&tv_end, NULL));
timersub(&tv_end, &tv_start, &tv_diff);
free(src);
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_memcpy(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_memcpy_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_memcpy_cycle(routines[i].fn, len, false);
result_cycle[1] =
do_memcpy_cycle(routines[i].fn, len, true);
} else {
result_bps[0] =
do_memcpy_gettimeofday(routines[i].fn,
len, false);
result_bps[1] =
do_memcpy_gettimeofday(routines[i].fn,
len, true);
}
} else {
if (use_cycle) {
result_cycle[pf] =
do_memcpy_cycle(routines[i].fn,
len, only_prefault);
} else {
result_bps[pf] =
do_memcpy_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;
}