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author | Emilio G. Cota <cota@braap.org> | 2018-09-10 19:27:43 -0400 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-10-02 18:47:55 +0200 |
commit | 82fdfcbe64ec09048d5f9b430b16231b9285d54b (patch) | |
tree | bb09dc74d42db8e9dc6ec217d617ed9590243aaf /tests/atomic64-bench.c | |
parent | 782da5b2921c4d18777d5d5bd9385b9f7beae360 (diff) | |
download | qemu-82fdfcbe64ec09048d5f9b430b16231b9285d54b.zip qemu-82fdfcbe64ec09048d5f9b430b16231b9285d54b.tar.gz qemu-82fdfcbe64ec09048d5f9b430b16231b9285d54b.tar.bz2 |
tests: add atomic64-bench
- With CONFIG_ATOMIC64:
$ tests/atomic64-bench -n 1
Throughput: 310.40 Mops/s
- Without:
$ tests/atomic64-bench -n 1
Throughput: 149.08 Mops/s
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20180910232752.31565-4-cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tests/atomic64-bench.c')
-rw-r--r-- | tests/atomic64-bench.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/tests/atomic64-bench.c b/tests/atomic64-bench.c new file mode 100644 index 0000000..7169256 --- /dev/null +++ b/tests/atomic64-bench.c @@ -0,0 +1,171 @@ +/* + * Copyright (C) 2018, Emilio G. Cota <cota@braap.org> + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ +#include "qemu/osdep.h" +#include "qemu/thread.h" +#include "qemu/host-utils.h" +#include "qemu/processor.h" + +struct thread_info { + uint64_t r; + uint64_t accesses; +} QEMU_ALIGNED(64); + +struct count { + int64_t i64; +} QEMU_ALIGNED(64); + +static QemuThread *threads; +static struct thread_info *th_info; +static unsigned int n_threads = 1; +static unsigned int n_ready_threads; +static struct count *counts; +static unsigned int duration = 1; +static unsigned int range = 1024; +static bool test_start; +static bool test_stop; + +static const char commands_string[] = + " -d = duration in seconds\n" + " -n = number of threads\n" + " -r = range (will be rounded up to pow2)"; + +static void usage_complete(char *argv[]) +{ + fprintf(stderr, "Usage: %s [options]\n", argv[0]); + fprintf(stderr, "options:\n%s\n", commands_string); +} + +/* + * From: https://en.wikipedia.org/wiki/Xorshift + * This is faster than rand_r(), and gives us a wider range (RAND_MAX is only + * guaranteed to be >= INT_MAX). + */ +static uint64_t xorshift64star(uint64_t x) +{ + x ^= x >> 12; /* a */ + x ^= x << 25; /* b */ + x ^= x >> 27; /* c */ + return x * UINT64_C(2685821657736338717); +} + +static void *thread_func(void *arg) +{ + struct thread_info *info = arg; + + atomic_inc(&n_ready_threads); + while (!atomic_read(&test_start)) { + cpu_relax(); + } + + while (!atomic_read(&test_stop)) { + unsigned int index; + + info->r = xorshift64star(info->r); + index = info->r & (range - 1); + atomic_read_i64(&counts[index].i64); + info->accesses++; + } + return NULL; +} + +static void run_test(void) +{ + unsigned int remaining; + unsigned int i; + + while (atomic_read(&n_ready_threads) != n_threads) { + cpu_relax(); + } + atomic_set(&test_start, true); + do { + remaining = sleep(duration); + } while (remaining); + atomic_set(&test_stop, true); + + for (i = 0; i < n_threads; i++) { + qemu_thread_join(&threads[i]); + } +} + +static void create_threads(void) +{ + unsigned int i; + + threads = g_new(QemuThread, n_threads); + th_info = g_new(struct thread_info, n_threads); + counts = g_malloc0_n(range, sizeof(*counts)); + + for (i = 0; i < n_threads; i++) { + struct thread_info *info = &th_info[i]; + + info->r = (i + 1) ^ time(NULL); + info->accesses = 0; + qemu_thread_create(&threads[i], NULL, thread_func, info, + QEMU_THREAD_JOINABLE); + } +} + +static void pr_params(void) +{ + printf("Parameters:\n"); + printf(" # of threads: %u\n", n_threads); + printf(" duration: %u\n", duration); + printf(" ops' range: %u\n", range); +} + +static void pr_stats(void) +{ + unsigned long long val = 0; + double tx; + int i; + + for (i = 0; i < n_threads; i++) { + val += th_info[i].accesses; + } + tx = val / duration / 1e6; + + printf("Results:\n"); + printf("Duration: %u s\n", duration); + printf(" Throughput: %.2f Mops/s\n", tx); + printf(" Throughput/thread: %.2f Mops/s/thread\n", tx / n_threads); +} + +static void parse_args(int argc, char *argv[]) +{ + int c; + + for (;;) { + c = getopt(argc, argv, "hd:n:r:"); + if (c < 0) { + break; + } + switch (c) { + case 'h': + usage_complete(argv); + exit(0); + case 'd': + duration = atoi(optarg); + break; + case 'n': + n_threads = atoi(optarg); + break; + case 'r': + range = pow2ceil(atoi(optarg)); + break; + } + } +} + +int main(int argc, char *argv[]) +{ + parse_args(argc, argv); + pr_params(); + create_threads(); + run_test(); + pr_stats(); + return 0; +} |