From 70c31264afd1f50c3b93a9007d97215ed5485e32 Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Wed, 25 Apr 2018 10:54:56 +0800 Subject: tests/atomic_add-bench: add -m option to use mutexes This allows us to use atomic-add-bench as a microbenchmark for evaluating qemu_mutex_lock's performance. Signed-off-by: Emilio G. Cota [cherry picked from https://github.com/cota/qemu/commit/f04f34df] Signed-off-by: Peter Xu Message-Id: <20180425025459.5258-2-peterx@redhat.com> Signed-off-by: Paolo Bonzini --- tests/atomic_add-bench.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'tests/atomic_add-bench.c') diff --git a/tests/atomic_add-bench.c b/tests/atomic_add-bench.c index caa1e8e689..f96d448f77 100644 --- a/tests/atomic_add-bench.c +++ b/tests/atomic_add-bench.c @@ -8,6 +8,7 @@ struct thread_info { } QEMU_ALIGNED(64); struct count { + QemuMutex lock; unsigned long val; } QEMU_ALIGNED(64); @@ -18,11 +19,13 @@ static unsigned int n_ready_threads; static struct count *counts; static unsigned int duration = 1; static unsigned int range = 1024; +static bool use_mutex; static bool test_start; static bool test_stop; static const char commands_string[] = " -n = number of threads\n" + " -m = use mutexes instead of atomic increments\n" " -d = duration in seconds\n" " -r = range (will be rounded up to pow2)"; @@ -59,7 +62,13 @@ static void *thread_func(void *arg) info->r = xorshift64star(info->r); index = info->r & (range - 1); - atomic_inc(&counts[index].val); + if (use_mutex) { + qemu_mutex_lock(&counts[index].lock); + counts[index].val += 1; + qemu_mutex_unlock(&counts[index].lock); + } else { + atomic_inc(&counts[index].val); + } } return NULL; } @@ -91,6 +100,9 @@ static void create_threads(void) th_info = g_new(struct thread_info, n_threads); counts = qemu_memalign(64, sizeof(*counts) * range); memset(counts, 0, sizeof(*counts) * range); + for (i = 0; i < range; i++) { + qemu_mutex_init(&counts[i].lock); + } for (i = 0; i < n_threads; i++) { struct thread_info *info = &th_info[i]; @@ -131,7 +143,7 @@ static void parse_args(int argc, char *argv[]) int c; for (;;) { - c = getopt(argc, argv, "hd:n:r:"); + c = getopt(argc, argv, "hd:n:mr:"); if (c < 0) { break; } @@ -145,6 +157,9 @@ static void parse_args(int argc, char *argv[]) case 'n': n_threads = atoi(optarg); break; + case 'm': + use_mutex = true; + break; case 'r': range = pow2ceil(atoi(optarg)); break; -- cgit v1.2.3