benchtests: Add malloc microbenchmark

Add a microbenchmark for measuring malloc and free performance with
varying numbers of threads. The benchmark allocates and frees buffers
of random sizes in a random order and measures the overall execution
time and RSS. Variants of the benchmark are run with 1, 8, 16 and
32 threads.

The random block sizes used follow an inverse square distribution
which is intended to mimic the behaviour of real applications which
tend to allocate many more small blocks than large ones.

ChangeLog:

2014-11-05  Will Newton  <will.newton@linaro.org>

	* benchtests/Makefile: (bench-malloc): Add malloc thread
	scalability benchmark.
	* benchtests/bench-malloc-threads.c: New file.
This commit is contained in:
Will Newton 2013-09-11 15:47:12 +01:00
parent be9d4ccc7f
commit b01ee67cb5
3 changed files with 325 additions and 3 deletions

View File

@ -1,3 +1,9 @@
2014-11-05 Will Newton <will.newton@linaro.org>
* benchtests/Makefile: (bench-malloc): Add malloc thread
scalability benchmark.
* benchtests/bench-malloc-threads.c: New file.
2014-11-05 Richard Earnshaw <rearnsha@arm.com>
* sysdeps/aarch64/strchrnul.S: New file.

View File

@ -44,8 +44,11 @@ benchset := $(string-bench-all) $(stdlib-bench)
CFLAGS-bench-ffs.c += -fno-builtin
CFLAGS-bench-ffsll.c += -fno-builtin
bench-malloc := malloc-thread
$(addprefix $(objpfx)bench-,$(bench-math)): $(libm)
$(addprefix $(objpfx)bench-,$(bench-pthread)): $(shared-thread-library)
$(objpfx)bench-malloc-thread: $(shared-thread-library)
@ -60,6 +63,7 @@ include ../Rules
binaries-bench := $(addprefix $(objpfx)bench-,$(bench))
binaries-benchset := $(addprefix $(objpfx)bench-,$(benchset))
binaries-bench-malloc := $(addprefix $(objpfx)bench-,$(bench-malloc))
# The default duration: 10 seconds.
ifndef BENCH_DURATION
@ -82,7 +86,8 @@ endif
# This makes sure CPPFLAGS-nonlib and CFLAGS-nonlib are passed
# for all these modules.
cpp-srcs-left := $(binaries-benchset:=.c) $(binaries-bench:=.c)
cpp-srcs-left := $(binaries-benchset:=.c) $(binaries-bench:=.c) \
$(binaries-bench-malloc:=.c)
lib := nonlib
include $(patsubst %,$(..)cppflags-iterator.mk,$(cpp-srcs-left))
@ -99,9 +104,10 @@ timing-type := $(objpfx)bench-timing-type
bench-clean:
rm -f $(binaries-bench) $(addsuffix .o,$(binaries-bench))
rm -f $(binaries-benchset) $(addsuffix .o,$(binaries-benchset))
rm -f $(binaries-bench-malloc) $(addsuffix .o,$(binaries-bench-malloc))
rm -f $(timing-type) $(addsuffix .o,$(timing-type))
bench: $(timing-type) bench-set bench-func
bench: $(timing-type) bench-set bench-func bench-malloc
bench-set: $(binaries-benchset)
for run in $^; do \
@ -109,6 +115,13 @@ bench-set: $(binaries-benchset)
$(run-bench) > $${run}.out; \
done
bench-malloc: $(binaries-bench-malloc)
run=$(objpfx)bench-malloc-thread; \
for thr in 1 8 16 32; do \
echo "Running $${run} $${thr}"; \
$(run-bench) $${thr} > $${run}-$${thr}.out; \
done
# Build and execute the benchmark functions. This target generates JSON
# formatted bench.out. Each of the programs produce independent JSON output,
# so one could even execute them individually and process it using any JSON
@ -134,7 +147,8 @@ bench-func: $(binaries-bench)
scripts/validate_benchout.py $(objpfx)bench.out \
scripts/benchout.schema.json
$(timing-type) $(binaries-bench) $(binaries-benchset): %: %.o $(objpfx)json-lib.o \
$(timing-type) $(binaries-bench) $(binaries-benchset) \
$(binaries-bench-malloc): %: %.o $(objpfx)json-lib.o \
$(sort $(filter $(common-objpfx)lib%,$(link-libc))) \
$(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
$(+link)

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@ -0,0 +1,302 @@
/* Benchmark malloc and free functions.
Copyright (C) 2013-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <math.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include "bench-timing.h"
#include "json-lib.h"
/* Benchmark duration in seconds. */
#define BENCHMARK_DURATION 60
#define RAND_SEED 88
#ifndef NUM_THREADS
# define NUM_THREADS 1
#endif
/* Maximum memory that can be allocated at any one time is:
NUM_THREADS * WORKING_SET_SIZE * MAX_ALLOCATION_SIZE
However due to the distribution of the random block sizes
the typical amount allocated will be much smaller. */
#define WORKING_SET_SIZE 1024
#define MIN_ALLOCATION_SIZE 4
#define MAX_ALLOCATION_SIZE 32768
/* Get a random block size with an inverse square distribution. */
static unsigned int
get_block_size (unsigned int rand_data)
{
/* Inverse square. */
const float exponent = -2;
/* Minimum value of distribution. */
const float dist_min = MIN_ALLOCATION_SIZE;
/* Maximum value of distribution. */
const float dist_max = MAX_ALLOCATION_SIZE;
float min_pow = powf (dist_min, exponent + 1);
float max_pow = powf (dist_max, exponent + 1);
float r = (float) rand_data / RAND_MAX;
return (unsigned int) powf ((max_pow - min_pow) * r + min_pow,
1 / (exponent + 1));
}
#define NUM_BLOCK_SIZES 8000
#define NUM_OFFSETS ((WORKING_SET_SIZE) * 4)
static unsigned int random_block_sizes[NUM_BLOCK_SIZES];
static unsigned int random_offsets[NUM_OFFSETS];
static void
init_random_values (void)
{
for (size_t i = 0; i < NUM_BLOCK_SIZES; i++)
random_block_sizes[i] = get_block_size (rand ());
for (size_t i = 0; i < NUM_OFFSETS; i++)
random_offsets[i] = rand () % WORKING_SET_SIZE;
}
static unsigned int
get_random_block_size (unsigned int *state)
{
unsigned int idx = *state;
if (idx >= NUM_BLOCK_SIZES - 1)
idx = 0;
else
idx++;
*state = idx;
return random_block_sizes[idx];
}
static unsigned int
get_random_offset (unsigned int *state)
{
unsigned int idx = *state;
if (idx >= NUM_OFFSETS - 1)
idx = 0;
else
idx++;
*state = idx;
return random_offsets[idx];
}
static volatile bool timeout;
static void
alarm_handler (int signum)
{
timeout = true;
}
/* Allocate and free blocks in a random order. */
static size_t
malloc_benchmark_loop (void **ptr_arr)
{
unsigned int offset_state = 0, block_state = 0;
size_t iters = 0;
while (!timeout)
{
unsigned int next_idx = get_random_offset (&offset_state);
unsigned int next_block = get_random_block_size (&block_state);
free (ptr_arr[next_idx]);
ptr_arr[next_idx] = malloc (next_block);
iters++;
}
return iters;
}
struct thread_args
{
size_t iters;
void **working_set;
timing_t elapsed;
};
static void *
benchmark_thread (void *arg)
{
struct thread_args *args = (struct thread_args *) arg;
size_t iters;
void *thread_set = args->working_set;
timing_t start, stop;
TIMING_NOW (start);
iters = malloc_benchmark_loop (thread_set);
TIMING_NOW (stop);
TIMING_DIFF (args->elapsed, start, stop);
args->iters = iters;
return NULL;
}
static timing_t
do_benchmark (size_t num_threads, size_t *iters)
{
timing_t elapsed = 0;
if (num_threads == 1)
{
timing_t start, stop;
void *working_set[WORKING_SET_SIZE];
memset (working_set, 0, sizeof (working_set));
TIMING_NOW (start);
*iters = malloc_benchmark_loop (working_set);
TIMING_NOW (stop);
TIMING_DIFF (elapsed, start, stop);
}
else
{
struct thread_args args[num_threads];
void *working_set[num_threads][WORKING_SET_SIZE];
pthread_t threads[num_threads];
memset (working_set, 0, sizeof (working_set));
*iters = 0;
for (size_t i = 0; i < num_threads; i++)
{
args[i].working_set = working_set[i];
pthread_create(&threads[i], NULL, benchmark_thread, &args[i]);
}
for (size_t i = 0; i < num_threads; i++)
{
pthread_join(threads[i], NULL);
TIMING_ACCUM (elapsed, args[i].elapsed);
*iters += args[i].iters;
}
}
return elapsed;
}
static void usage(const char *name)
{
fprintf (stderr, "%s: <num_threads>\n", name);
exit (1);
}
int
main (int argc, char **argv)
{
timing_t cur;
size_t iters = 0, num_threads = 1;
unsigned long res;
json_ctx_t json_ctx;
double d_total_s, d_total_i;
struct sigaction act;
if (argc == 1)
num_threads = 1;
else if (argc == 2)
{
long ret;
errno = 0;
ret = strtol(argv[1], NULL, 10);
if (errno || ret == 0)
usage(argv[0]);
num_threads = ret;
}
else
usage(argv[0]);
init_random_values ();
json_init (&json_ctx, 0, stdout);
json_document_begin (&json_ctx);
json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
json_attr_object_begin (&json_ctx, "functions");
json_attr_object_begin (&json_ctx, "malloc");
json_attr_object_begin (&json_ctx, "");
TIMING_INIT (res);
(void) res;
memset (&act, 0, sizeof (act));
act.sa_handler = &alarm_handler;
sigaction (SIGALRM, &act, NULL);
alarm (BENCHMARK_DURATION);
cur = do_benchmark (num_threads, &iters);
struct rusage usage;
getrusage(RUSAGE_SELF, &usage);
d_total_s = cur;
d_total_i = iters;
json_attr_double (&json_ctx, "duration", d_total_s);
json_attr_double (&json_ctx, "iterations", d_total_i);
json_attr_double (&json_ctx, "time_per_iteration", d_total_s / d_total_i);
json_attr_double (&json_ctx, "max_rss", usage.ru_maxrss);
json_attr_double (&json_ctx, "threads", num_threads);
json_attr_double (&json_ctx, "min_size", MIN_ALLOCATION_SIZE);
json_attr_double (&json_ctx, "max_size", MAX_ALLOCATION_SIZE);
json_attr_double (&json_ctx, "random_seed", RAND_SEED);
json_attr_object_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_document_end (&json_ctx);
return 0;
}