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btrfs-progs: crypto: add perf support to speed test

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Use perf events to read the cycle count, this should work on all
architectures. Enabled by option --perf and the sysctl
kernel.perf_event_paranoid must be 0 or 1.

The results are roughly the same as for raw cycles on x86_64 but worse
because of the additional overhead (read, context switch):

Block size:     4096
Iterations:     100000
Implementation: builtin
Units:          CPU cycles

    NULL-NOP: cycles:     42719688, cycles/i      427
 NULL-MEMCPY: cycles:     72941208, cycles/i      729,    18670.314 MiB/s
      CRC32C: cycles:    183709926, cycles/i     1837,     7413.009 MiB/s
      XXHASH: cycles:    136727614, cycles/i     1367,     9960.264 MiB/s
      SHA256: cycles:  10711594532, cycles/i   107115,      127.137 MiB/s
      BLAKE2: cycles:   2256957529, cycles/i    22569,      603.398 MiB/s

Block size:     4096
Iterations:     100000
Implementation: builtin
Units:          perf event: CPU cycles

    NULL-NOP: perf_c:     29649530, perf_c/i      296
 NULL-MEMCPY: perf_c:     59954062, perf_c/i      599,    15137.464 MiB/s
      CRC32C: perf_c:    179009071, perf_c/i     1790,     6929.460 MiB/s
      XXHASH: perf_c:    136413509, perf_c/i     1364,     9982.950 MiB/s
      SHA256: perf_c:  10997356664, perf_c/i   109973,      127.046 MiB/s
      BLAKE2: perf_c:   2379077576, perf_c/i    23790,      588.780 MiB/s

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2021-06-01 21:41:53 +02:00
parent 1d4bab875a
commit 9527bc0649
2 changed files with 104 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
configure.ac
View file

@ -60,6 +60,9 @@ AC_CHECK_FUNCS([reallocarray])
AC_CHECK_FUNCS([clock_gettime])
AC_CHECK_HEADERS([linux/perf_event.h])
AC_CHECK_HEADERS([linux/hw_breakpoint.h])
m4_ifndef([PKG_PROG_PKG_CONFIG],
[m4_fatal([Could not locate the pkg-config autoconf
macros. These are usually located in /usr/share/aclocal/pkg.m4.

116
crypto/hash-speedtest.c
View file

@ -1,6 +1,13 @@
#include "../kerncompat.h"
#include <time.h>
#include <getopt.h>
#include <unistd.h>
#if HAVE_LINUX_PERF_EVENT_H == 1 && HAVE_LINUX_HW_BREAKPOINT_H == 1
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
#include <sys/syscall.h>
#define HAVE_PERF
#endif
#include "crypto/hash.h"
#include "crypto/crc32c.h"
#include "crypto/sha.h"
@ -12,6 +19,12 @@ static const int cycles_supported = 1;
static const int cycles_supported = 0;
#endif
enum {
UNITS_CYCLES,
UNITS_TIME,
UNITS_PERF,
};
const int blocksize = 4096;
int iterations = 100000;
@ -31,14 +44,56 @@ static inline u64 read_tsc(void)
return rdtsc();
}
#define get_cycles() read_tsc()
#define cpu_cycles() read_tsc()
#else
#define get_cycles() (0)
#define cpu_cycles() (0)
#endif
#ifdef HAVE_PERF
static int perf_fd = -1;
static int perf_init(void)
{
static struct perf_event_attr attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES
};
perf_fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
return perf_fd;
}
static void perf_finish(void)
{
close(perf_fd);
}
static long long perf_cycles(void)
{
long long cycles;
int ret;
ret = read(perf_fd, &cycles, sizeof(cycles));
if (ret != sizeof(cycles))
return 0;
return cycles;
}
#else
static int perf_init()
{
errno = EOPNOTSUPP;
return -1;
}
static void perf_finish() {}
static long long perf_cycles() {
return 0;
}
#endif
static inline u64 get_time(void)
{
struct timespec ts;
@ -47,6 +102,16 @@ static inline u64 get_time(void)
return ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec;
}
static inline u64 get_cycles(int units)
{
switch (units) {
case UNITS_CYCLES: return cpu_cycles();
case UNITS_TIME: return get_time();
case UNITS_PERF: return perf_cycles();
}
return 0;
}
/* Read the input and copy last bytes as the hash */
static int hash_null_memcpy(const u8 *buf, size_t length, u8 *out)
{
@ -68,11 +133,22 @@ static int hash_null_nop(const u8 *buf, size_t length, u8 *out)
return 0;
}
const char *units_to_str(int units)
static const char *units_to_desc(int units)
{
switch (units) {
case 0: return "cycles";
case 1: return "nsecs";
case UNITS_CYCLES: return "CPU cycles";
case UNITS_TIME: return "time: ns";
case UNITS_PERF: return "perf event: CPU cycles";
}
return "unknown";
}
static const char *units_to_str(int units)
{
switch (units) {
case UNITS_CYCLES: return "cycles";
case UNITS_TIME: return "nsecs";
case UNITS_PERF: return "perf_c";
}
return "unknown";
}
@ -96,18 +172,19 @@ int main(int argc, char **argv) {
{ .name = "SHA256", .digest = hash_sha256, .digest_size = 32 },
{ .name = "BLAKE2", .digest = hash_blake2b, .digest_size = 32 },
};
int units = 0;
int units = UNITS_CYCLES;
optind = 0;
while (1) {
static const struct option long_options[] = {
{ "cycles", no_argument, NULL, 'c' },
{ "time", no_argument, NULL, 't' },
{ "perf", no_argument, NULL, 'p' },
{ NULL, 0, NULL, 0}
};
int c;
c = getopt_long(argc, argv, "ct", long_options, NULL);
c = getopt_long(argc, argv, "ctp", long_options, NULL);
if (c < 0)
break;
switch (c) {
@ -117,10 +194,18 @@ int main(int argc, char **argv) {
"ERROR: cannot measure cycles on this arch, use --time\n");
return 1;
}
units = 0;
units = UNITS_CYCLES;
break;
case 't':
units = 1;
units = UNITS_TIME;
break;
case 'p':
if (perf_init() == -1) {
fprintf(stderr,
"ERROR: cannot initialize perf, please check sysctl kernel.perf_event_paranoid: %m\n");
return 1;
}
units = UNITS_PERF;
break;
default:
fprintf(stderr, "ERROR: unknown option\n");
@ -140,33 +225,33 @@ int main(int argc, char **argv) {
printf("Block size: %d\n", blocksize);
printf("Iterations: %d\n", iterations);
printf("Implementation: %s\n", CRYPTOPROVIDER);
printf("Units: %s\n", units_to_str(units));
printf("Units: %s\n", units_to_desc(units));
printf("\n");
for (idx = 0; idx < ARRAY_SIZE(contestants); idx++) {
struct contestant *c = &contestants[idx];
u64 start, end;
u64 tstart, tend;
u64 total;
u64 total = 0;
printf("%12s: ", c->name);
fflush(stdout);
tstart = get_time();
start = get_cycles();
start = get_cycles(units);
for (iter = 0; iter < iterations; iter++) {
memset(buf, iter & 0xFF, blocksize);
memset(hash, 0, 32);
c->digest(buf, blocksize, hash);
}
end = get_cycles();
end = get_cycles(units);
tend = get_time();
c->cycles = end - start;
c->time = tend - tstart;
if (units == 0)
if (units == UNITS_CYCLES || units == UNITS_PERF)
total = c->cycles;
if (units == 1)
if (units == UNITS_TIME)
total = c->time;
printf("%s: %12llu, %s/i %8llu",
@ -182,6 +267,7 @@ int main(int argc, char **argv) {
}
putchar('\n');
}
perf_finish();
return 0;
}