[mirror_ubuntu-artful-kernel.git] / tools / perf / bench / futex-hash.c

/*
 * Copyright (C) 2013  Davidlohr Bueso <davidlohr@hp.com>
 *
 * futex-hash: Stress the hell out of the Linux kernel futex uaddr hashing.
 *
 * This program is particularly useful for measuring the kernel's futex hash
 * table/function implementation. In order for it to make sense, use with as
 * many threads and futexes as possible.
 */

/* For the CLR_() macros */
#include <pthread.h>

#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <sys/time.h>

#include "../util/stat.h"
#include <subcmd/parse-options.h>
#include "bench.h"
#include "futex.h"

#include <err.h>
#include <sys/time.h>

static unsigned int nthreads = 0;
static unsigned int nsecs    = 10;
/* amount of futexes per thread */
static unsigned int nfutexes = 1024;
static bool fshared = false, done = false, silent = false;
static int futex_flag = 0;

struct timeval start, end, runtime;
static pthread_mutex_t thread_lock;
static unsigned int threads_starting;
static struct stats throughput_stats;
static pthread_cond_t thread_parent, thread_worker;

struct worker {
	int tid;
	u_int32_t *futex;
	pthread_t thread;
	unsigned long ops;
};

static const struct option options[] = {
	OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
	OPT_UINTEGER('r', "runtime", &nsecs,    "Specify runtime (in seconds)"),
	OPT_UINTEGER('f', "futexes", &nfutexes, "Specify amount of futexes per threads"),
	OPT_BOOLEAN( 's', "silent",  &silent,   "Silent mode: do not display data/details"),
	OPT_BOOLEAN( 'S', "shared",  &fshared,  "Use shared futexes instead of private ones"),
	OPT_END()
};

static const char * const bench_futex_hash_usage[] = {
	"perf bench futex hash <options>",
	NULL
};

static void *workerfn(void *arg)
{
	int ret;
	struct worker *w = (struct worker *) arg;
	unsigned int i;
	unsigned long ops = w->ops; /* avoid cacheline bouncing */

	pthread_mutex_lock(&thread_lock);
	threads_starting--;
	if (!threads_starting)
		pthread_cond_signal(&thread_parent);
	pthread_cond_wait(&thread_worker, &thread_lock);
	pthread_mutex_unlock(&thread_lock);

	do {
		for (i = 0; i < nfutexes; i++, ops++) {
			/*
			 * We want the futex calls to fail in order to stress
			 * the hashing of uaddr and not measure other steps,
			 * such as internal waitqueue handling, thus enlarging
			 * the critical region protected by hb->lock.
			 */
			ret = futex_wait(&w->futex[i], 1234, NULL, futex_flag);
			if (!silent &&
			    (!ret || errno != EAGAIN || errno != EWOULDBLOCK))
				warn("Non-expected futex return call");
		}
	}  while (!done);

	w->ops = ops;
	return NULL;
}

static void toggle_done(int sig __maybe_unused,
			siginfo_t *info __maybe_unused,
			void *uc __maybe_unused)
{
	/* inform all threads that we're done for the day */
	done = true;
	gettimeofday(&end, NULL);
	timersub(&end, &start, &runtime);
}

static void print_summary(void)
{
	unsigned long avg = avg_stats(&throughput_stats);
	double stddev = stddev_stats(&throughput_stats);

	printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n",
	       !silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg),
	       (int) runtime.tv_sec);
}

int bench_futex_hash(int argc, const char **argv,
		     const char *prefix __maybe_unused)
{
	int ret = 0;
	cpu_set_t cpu;
	struct sigaction act;
	unsigned int i, ncpus;
	pthread_attr_t thread_attr;
	struct worker *worker = NULL;

	argc = parse_options(argc, argv, options, bench_futex_hash_usage, 0);
	if (argc) {
		usage_with_options(bench_futex_hash_usage, options);
		exit(EXIT_FAILURE);
	}

	ncpus = sysconf(_SC_NPROCESSORS_ONLN);
	nsecs = futexbench_sanitize_numeric(nsecs);
	nfutexes = futexbench_sanitize_numeric(nfutexes);

	sigfillset(&act.sa_mask);
	act.sa_sigaction = toggle_done;
	sigaction(SIGINT, &act, NULL);

	if (!nthreads) /* default to the number of CPUs */
		nthreads = ncpus;
	else
		nthreads = futexbench_sanitize_numeric(nthreads);

	worker = calloc(nthreads, sizeof(*worker));
	if (!worker)
		goto errmem;

	if (!fshared)
		futex_flag = FUTEX_PRIVATE_FLAG;

	printf("Run summary [PID %d]: %d threads, each operating on %d [%s] futexes for %d secs.\n\n",
	       getpid(), nthreads, nfutexes, fshared ? "shared":"private", nsecs);

	init_stats(&throughput_stats);
	pthread_mutex_init(&thread_lock, NULL);
	pthread_cond_init(&thread_parent, NULL);
	pthread_cond_init(&thread_worker, NULL);

	threads_starting = nthreads;
	pthread_attr_init(&thread_attr);
	gettimeofday(&start, NULL);
	for (i = 0; i < nthreads; i++) {
		worker[i].tid = i;
		worker[i].futex = calloc(nfutexes, sizeof(*worker[i].futex));
		if (!worker[i].futex)
			goto errmem;

		CPU_ZERO(&cpu);
		CPU_SET(i % ncpus, &cpu);

		ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu);
		if (ret)
			err(EXIT_FAILURE, "pthread_attr_setaffinity_np");

		ret = pthread_create(&worker[i].thread, &thread_attr, workerfn,
				     (void *)(struct worker *) &worker[i]);
		if (ret)
			err(EXIT_FAILURE, "pthread_create");

	}
	pthread_attr_destroy(&thread_attr);

	pthread_mutex_lock(&thread_lock);
	while (threads_starting)
		pthread_cond_wait(&thread_parent, &thread_lock);
	pthread_cond_broadcast(&thread_worker);
	pthread_mutex_unlock(&thread_lock);

	sleep(nsecs);
	toggle_done(0, NULL, NULL);

	for (i = 0; i < nthreads; i++) {
		ret = pthread_join(worker[i].thread, NULL);
		if (ret)
			err(EXIT_FAILURE, "pthread_join");
	}

	/* cleanup & report results */
	pthread_cond_destroy(&thread_parent);
	pthread_cond_destroy(&thread_worker);
	pthread_mutex_destroy(&thread_lock);

	for (i = 0; i < nthreads; i++) {
		unsigned long t = worker[i].ops/runtime.tv_sec;
		update_stats(&throughput_stats, t);
		if (!silent) {
			if (nfutexes == 1)
				printf("[thread %2d] futex: %p [ %ld ops/sec ]\n",
				       worker[i].tid, &worker[i].futex[0], t);
			else
				printf("[thread %2d] futexes: %p ... %p [ %ld ops/sec ]\n",
				       worker[i].tid, &worker[i].futex[0],
				       &worker[i].futex[nfutexes-1], t);
		}

		free(worker[i].futex);
	}

	print_summary();

	free(worker);
	return ret;
errmem:
	err(EXIT_FAILURE, "calloc");
}
Commit	Line	Data
a0439711 DB	1	/*
	2	* Copyright (C) 2013 Davidlohr Bueso <davidlohr@hp.com>
	3	*
	4	* futex-hash: Stress the hell out of the Linux kernel futex uaddr hashing.
	5	*
	6	* This program is particularly useful for measuring the kernel's futex hash
	7	* table/function implementation. In order for it to make sense, use with as
	8	* many threads and futexes as possible.
	9	*/
	10
8a158589 ACM	11	/* For the CLR_() macros */
	12	#include <pthread.h>
	13
9c304f6c ACM	14	#include <errno.h>
	15	#include <signal.h>
	16	#include <stdlib.h>
86695f59	17	#include <linux/compiler.h>
9c304f6c ACM	18	#include <linux/kernel.h>
	19	#include <sys/time.h>
	20
a0439711	21	#include "../util/stat.h"
4b6ab94e	22	#include <subcmd/parse-options.h>
a0439711 DB	23	#include "bench.h"
	24	#include "futex.h"
	25
	26	#include <err.h>
a0439711	27	#include <sys/time.h>
a0439711 DB	28
	29	static unsigned int nthreads = 0;
	30	static unsigned int nsecs = 10;
	31	/* amount of futexes per thread */
	32	static unsigned int nfutexes = 1024;
	33	static bool fshared = false, done = false, silent = false;
86c87e13	34	static int futex_flag = 0;
a0439711 DB	35
	36	struct timeval start, end, runtime;
	37	static pthread_mutex_t thread_lock;
	38	static unsigned int threads_starting;
	39	static struct stats throughput_stats;
	40	static pthread_cond_t thread_parent, thread_worker;
	41
	42	struct worker {
	43	int tid;
	44	u_int32_t *futex;
	45	pthread_t thread;
	46	unsigned long ops;
e2e1680f	47	};
a0439711 DB	48
	49	static const struct option options[] = {
	50	OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
	51	OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"),
	52	OPT_UINTEGER('f', "futexes", &nfutexes, "Specify amount of futexes per threads"),
	53	OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"),
	54	OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"),
	55	OPT_END()
	56	};
	57
	58	static const char * const bench_futex_hash_usage[] = {
	59	"perf bench futex hash <options>",
	60	NULL
	61	};
	62
	63	static void workerfn(void arg)
	64	{
	65	int ret;
a0439711	66	struct worker w = (struct worker ) arg;
e2e1680f DB	67	unsigned int i;
e2e1680f DB	68	unsigned long ops = w->ops; /* avoid cacheline bouncing */
a0439711 DB	69
	70	pthread_mutex_lock(&thread_lock);
	71	threads_starting--;
	72	if (!threads_starting)
	73	pthread_cond_signal(&thread_parent);
	74	pthread_cond_wait(&thread_worker, &thread_lock);
	75	pthread_mutex_unlock(&thread_lock);
	76
	77	do {
e2e1680f	78	for (i = 0; i < nfutexes; i++, ops++) {
a0439711 DB	79	/*
	80	* We want the futex calls to fail in order to stress
	81	* the hashing of uaddr and not measure other steps,
	82	* such as internal waitqueue handling, thus enlarging
	83	* the critical region protected by hb->lock.
	84	*/
86c87e13	85	ret = futex_wait(&w->futex[i], 1234, NULL, futex_flag);
a0439711 DB	86	if (!silent &&
	87	(!ret \|\| errno != EAGAIN \|\| errno != EWOULDBLOCK))
	88	warn("Non-expected futex return call");
	89	}
	90	} while (!done);
	91
e2e1680f	92	w->ops = ops;
a0439711 DB	93	return NULL;
	94	}
	95
	96	static void toggle_done(int sig __maybe_unused,
	97	siginfo_t *info __maybe_unused,
	98	void *uc __maybe_unused)
	99	{
	100	/* inform all threads that we're done for the day */
	101	done = true;
	102	gettimeofday(&end, NULL);
	103	timersub(&end, &start, &runtime);
	104	}
	105
	106	static void print_summary(void)
	107	{
	108	unsigned long avg = avg_stats(&throughput_stats);
	109	double stddev = stddev_stats(&throughput_stats);
	110
	111	printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n",
	112	!silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg),
	113	(int) runtime.tv_sec);
	114	}
	115
	116	int bench_futex_hash(int argc, const char **argv,
	117	const char *prefix __maybe_unused)
	118	{
	119	int ret = 0;
	120	cpu_set_t cpu;
	121	struct sigaction act;
	122	unsigned int i, ncpus;
	123	pthread_attr_t thread_attr;
	124	struct worker *worker = NULL;
	125
	126	argc = parse_options(argc, argv, options, bench_futex_hash_usage, 0);
	127	if (argc) {
	128	usage_with_options(bench_futex_hash_usage, options);
	129	exit(EXIT_FAILURE);
	130	}
	131
	132	ncpus = sysconf(_SC_NPROCESSORS_ONLN);
60758d66 DB	133	nsecs = futexbench_sanitize_numeric(nsecs);
60758d66 DB	134	nfutexes = futexbench_sanitize_numeric(nfutexes);
a0439711 DB	135
	136	sigfillset(&act.sa_mask);
	137	act.sa_sigaction = toggle_done;
	138	sigaction(SIGINT, &act, NULL);
	139
	140	if (!nthreads) /* default to the number of CPUs */
	141	nthreads = ncpus;
60758d66 DB	142	else
60758d66 DB	143	nthreads = futexbench_sanitize_numeric(nthreads);
a0439711 DB	144
	145	worker = calloc(nthreads, sizeof(*worker));
	146	if (!worker)
	147	goto errmem;
	148
86c87e13 DB	149	if (!fshared)
	150	futex_flag = FUTEX_PRIVATE_FLAG;
	151
a0439711 DB	152	printf("Run summary [PID %d]: %d threads, each operating on %d [%s] futexes for %d secs.\n\n",
	153	getpid(), nthreads, nfutexes, fshared ? "shared":"private", nsecs);
	154
	155	init_stats(&throughput_stats);
	156	pthread_mutex_init(&thread_lock, NULL);
	157	pthread_cond_init(&thread_parent, NULL);
	158	pthread_cond_init(&thread_worker, NULL);
	159
	160	threads_starting = nthreads;
	161	pthread_attr_init(&thread_attr);
	162	gettimeofday(&start, NULL);
	163	for (i = 0; i < nthreads; i++) {
	164	worker[i].tid = i;
	165	worker[i].futex = calloc(nfutexes, sizeof(*worker[i].futex));
	166	if (!worker[i].futex)
	167	goto errmem;
	168
	169	CPU_ZERO(&cpu);
	170	CPU_SET(i % ncpus, &cpu);
	171
	172	ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu);
	173	if (ret)
	174	err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
	175
	176	ret = pthread_create(&worker[i].thread, &thread_attr, workerfn,
	177	(void )(struct worker ) &worker[i]);
	178	if (ret)
	179	err(EXIT_FAILURE, "pthread_create");
	180
	181	}
	182	pthread_attr_destroy(&thread_attr);
	183
	184	pthread_mutex_lock(&thread_lock);
	185	while (threads_starting)
	186	pthread_cond_wait(&thread_parent, &thread_lock);
	187	pthread_cond_broadcast(&thread_worker);
	188	pthread_mutex_unlock(&thread_lock);
	189
	190	sleep(nsecs);
	191	toggle_done(0, NULL, NULL);
	192
	193	for (i = 0; i < nthreads; i++) {
	194	ret = pthread_join(worker[i].thread, NULL);
	195	if (ret)
	196	err(EXIT_FAILURE, "pthread_join");
	197	}
	198
	199	/* cleanup & report results */
	200	pthread_cond_destroy(&thread_parent);
	201	pthread_cond_destroy(&thread_worker);
	202	pthread_mutex_destroy(&thread_lock);
	203
	204	for (i = 0; i < nthreads; i++) {
	205	unsigned long t = worker[i].ops/runtime.tv_sec;
	206	update_stats(&throughput_stats, t);
	207	if (!silent) {
	208	if (nfutexes == 1)
	209	printf("[thread %2d] futex: %p [ %ld ops/sec ]\n",
	210	worker[i].tid, &worker[i].futex[0], t);
	211	else
	212	printf("[thread %2d] futexes: %p ... %p [ %ld ops/sec ]\n",
	213	worker[i].tid, &worker[i].futex[0],
	214	&worker[i].futex[nfutexes-1], t);
	215	}
216
217	free(worker[i].futex);
218	}
219
220	print_summary();
221
222	free(worker);
223	return ret;
224	errmem:
225	err(EXIT_FAILURE, "calloc");
226	}