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-rw-r--r--tools/perf/bench/bench.h3
-rw-r--r--tools/perf/bench/futex-hash.c212
-rw-r--r--tools/perf/bench/futex-requeue.c211
-rw-r--r--tools/perf/bench/futex-wake.c201
-rw-r--r--tools/perf/bench/futex.h71
5 files changed, 698 insertions, 0 deletions
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 0fdc85269c4d..eba46709b279 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -31,6 +31,9 @@ extern int bench_sched_pipe(int argc, const char **argv, const char *prefix);
extern int bench_mem_memcpy(int argc, const char **argv,
const char *prefix __maybe_unused);
extern int bench_mem_memset(int argc, const char **argv, const char *prefix);
+extern int bench_futex_hash(int argc, const char **argv, const char *prefix);
+extern int bench_futex_wake(int argc, const char **argv, const char *prefix);
+extern int bench_futex_requeue(int argc, const char **argv, const char *prefix);
#define BENCH_FORMAT_DEFAULT_STR "default"
#define BENCH_FORMAT_DEFAULT 0
diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
new file mode 100644
index 000000000000..a84206e9c4aa
--- /dev/null
+++ b/tools/perf/bench/futex-hash.c
@@ -0,0 +1,212 @@
+/*
+ * 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.
+ */
+
+#include "../perf.h"
+#include "../util/util.h"
+#include "../util/stat.h"
+#include "../util/parse-options.h"
+#include "../util/header.h"
+#include "bench.h"
+#include "futex.h"
+
+#include <err.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <pthread.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;
+
+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;
+ unsigned int i;
+ struct worker *w = (struct worker *) arg;
+
+ 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++, w->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,
+ fshared ? 0 : FUTEX_PRIVATE_FLAG);
+ if (!silent &&
+ (!ret || errno != EAGAIN || errno != EWOULDBLOCK))
+ warn("Non-expected futex return call");
+ }
+ } while (!done);
+
+ 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);
+
+ sigfillset(&act.sa_mask);
+ act.sa_sigaction = toggle_done;
+ sigaction(SIGINT, &act, NULL);
+
+ if (!nthreads) /* default to the number of CPUs */
+ nthreads = ncpus;
+
+ worker = calloc(nthreads, sizeof(*worker));
+ if (!worker)
+ goto errmem;
+
+ 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");
+}
diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
new file mode 100644
index 000000000000..a16255876f1d
--- /dev/null
+++ b/tools/perf/bench/futex-requeue.c
@@ -0,0 +1,211 @@
+/*
+ * Copyright (C) 2013 Davidlohr Bueso <davidlohr@hp.com>
+ *
+ * futex-requeue: Block a bunch of threads on futex1 and requeue them
+ * on futex2, N at a time.
+ *
+ * This program is particularly useful to measure the latency of nthread
+ * requeues without waking up any tasks -- thus mimicking a regular futex_wait.
+ */
+
+#include "../perf.h"
+#include "../util/util.h"
+#include "../util/stat.h"
+#include "../util/parse-options.h"
+#include "../util/header.h"
+#include "bench.h"
+#include "futex.h"
+
+#include <err.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <pthread.h>
+
+static u_int32_t futex1 = 0, futex2 = 0;
+
+/*
+ * How many tasks to requeue at a time.
+ * Default to 1 in order to make the kernel work more.
+ */
+static unsigned int nrequeue = 1;
+
+/*
+ * There can be significant variance from run to run,
+ * the more repeats, the more exact the overall avg and
+ * the better idea of the futex latency.
+ */
+static unsigned int repeat = 10;
+
+static pthread_t *worker;
+static bool done = 0, silent = 0;
+static pthread_mutex_t thread_lock;
+static pthread_cond_t thread_parent, thread_worker;
+static struct stats requeuetime_stats, requeued_stats;
+static unsigned int ncpus, threads_starting, nthreads = 0;
+
+static const struct option options[] = {
+ OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
+ OPT_UINTEGER('q', "nrequeue", &nrequeue, "Specify amount of threads to requeue at once"),
+ OPT_UINTEGER('r', "repeat", &repeat, "Specify amount of times to repeat the run"),
+ OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"),
+ OPT_END()
+};
+
+static const char * const bench_futex_requeue_usage[] = {
+ "perf bench futex requeue <options>",
+ NULL
+};
+
+static void print_summary(void)
+{
+ double requeuetime_avg = avg_stats(&requeuetime_stats);
+ double requeuetime_stddev = stddev_stats(&requeuetime_stats);
+ unsigned int requeued_avg = avg_stats(&requeued_stats);
+
+ printf("Requeued %d of %d threads in %.4f ms (+-%.2f%%)\n",
+ requeued_avg,
+ nthreads,
+ requeuetime_avg/1e3,
+ rel_stddev_stats(requeuetime_stddev, requeuetime_avg));
+}
+
+static void *workerfn(void *arg __maybe_unused)
+{
+ 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);
+
+ futex_wait(&futex1, 0, NULL, FUTEX_PRIVATE_FLAG);
+ return NULL;
+}
+
+static void block_threads(pthread_t *w,
+ pthread_attr_t thread_attr)
+{
+ cpu_set_t cpu;
+ unsigned int i;
+
+ threads_starting = nthreads;
+
+ /* create and block all threads */
+ for (i = 0; i < nthreads; i++) {
+ CPU_ZERO(&cpu);
+ CPU_SET(i % ncpus, &cpu);
+
+ if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu))
+ err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+
+ if (pthread_create(&w[i], &thread_attr, workerfn, NULL))
+ err(EXIT_FAILURE, "pthread_create");
+ }
+}
+
+static void toggle_done(int sig __maybe_unused,
+ siginfo_t *info __maybe_unused,
+ void *uc __maybe_unused)
+{
+ done = true;
+}
+
+int bench_futex_requeue(int argc, const char **argv,
+ const char *prefix __maybe_unused)
+{
+ int ret = 0;
+ unsigned int i, j;
+ struct sigaction act;
+ pthread_attr_t thread_attr;
+
+ argc = parse_options(argc, argv, options, bench_futex_requeue_usage, 0);
+ if (argc)
+ goto err;
+
+ ncpus = sysconf(_SC_NPROCESSORS_ONLN);
+
+ sigfillset(&act.sa_mask);
+ act.sa_sigaction = toggle_done;
+ sigaction(SIGINT, &act, NULL);
+
+ if (!nthreads)
+ nthreads = ncpus;
+
+ worker = calloc(nthreads, sizeof(*worker));
+ if (!worker)
+ err(EXIT_FAILURE, "calloc");
+
+ printf("Run summary [PID %d]: Requeuing %d threads (from %p to %p), "
+ "%d at a time.\n\n",
+ getpid(), nthreads, &futex1, &futex2, nrequeue);
+
+ init_stats(&requeued_stats);
+ init_stats(&requeuetime_stats);
+ pthread_attr_init(&thread_attr);
+ pthread_mutex_init(&thread_lock, NULL);
+ pthread_cond_init(&thread_parent, NULL);
+ pthread_cond_init(&thread_worker, NULL);
+
+ for (j = 0; j < repeat && !done; j++) {
+ unsigned int nrequeued = 0;
+ struct timeval start, end, runtime;
+
+ /* create, launch & block all threads */
+ block_threads(worker, thread_attr);
+
+ /* make sure all threads are already blocked */
+ 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);
+
+ usleep(100000);
+
+ /* Ok, all threads are patiently blocked, start requeueing */
+ gettimeofday(&start, NULL);
+ for (nrequeued = 0; nrequeued < nthreads; nrequeued += nrequeue)
+ /*
+ * Do not wakeup any tasks blocked on futex1, allowing
+ * us to really measure futex_wait functionality.
+ */
+ futex_cmp_requeue(&futex1, 0, &futex2, 0, nrequeue,
+ FUTEX_PRIVATE_FLAG);
+ gettimeofday(&end, NULL);
+ timersub(&end, &start, &runtime);
+
+ update_stats(&requeued_stats, nrequeued);
+ update_stats(&requeuetime_stats, runtime.tv_usec);
+
+ if (!silent) {
+ printf("[Run %d]: Requeued %d of %d threads in %.4f ms\n",
+ j + 1, nrequeued, nthreads, runtime.tv_usec/1e3);
+ }
+
+ /* everybody should be blocked on futex2, wake'em up */
+ nrequeued = futex_wake(&futex2, nthreads, FUTEX_PRIVATE_FLAG);
+ if (nthreads != nrequeued)
+ warnx("couldn't wakeup all tasks (%d/%d)", nrequeued, nthreads);
+
+ for (i = 0; i < nthreads; i++) {
+ ret = pthread_join(worker[i], 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);
+ pthread_attr_destroy(&thread_attr);
+
+ print_summary();
+
+ free(worker);
+ return ret;
+err:
+ usage_with_options(bench_futex_requeue_usage, options);
+ exit(EXIT_FAILURE);
+}
diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
new file mode 100644
index 000000000000..d096169b161e
--- /dev/null
+++ b/tools/perf/bench/futex-wake.c
@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) 2013 Davidlohr Bueso <davidlohr@hp.com>
+ *
+ * futex-wake: Block a bunch of threads on a futex and wake'em up, N at a time.
+ *
+ * This program is particularly useful to measure the latency of nthread wakeups
+ * in non-error situations: all waiters are queued and all wake calls wakeup
+ * one or more tasks, and thus the waitqueue is never empty.
+ */
+
+#include "../perf.h"
+#include "../util/util.h"
+#include "../util/stat.h"
+#include "../util/parse-options.h"
+#include "../util/header.h"
+#include "bench.h"
+#include "futex.h"
+
+#include <err.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <pthread.h>
+
+/* all threads will block on the same futex */
+static u_int32_t futex1 = 0;
+
+/*
+ * How many wakeups to do at a time.
+ * Default to 1 in order to make the kernel work more.
+ */
+static unsigned int nwakes = 1;
+
+/*
+ * There can be significant variance from run to run,
+ * the more repeats, the more exact the overall avg and
+ * the better idea of the futex latency.
+ */
+static unsigned int repeat = 10;
+
+pthread_t *worker;
+static bool done = 0, silent = 0;
+static pthread_mutex_t thread_lock;
+static pthread_cond_t thread_parent, thread_worker;
+static struct stats waketime_stats, wakeup_stats;
+static unsigned int ncpus, threads_starting, nthreads = 0;
+
+static const struct option options[] = {
+ OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
+ OPT_UINTEGER('w', "nwakes", &nwakes, "Specify amount of threads to wake at once"),
+ OPT_UINTEGER('r', "repeat", &repeat, "Specify amount of times to repeat the run"),
+ OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"),
+ OPT_END()
+};
+
+static const char * const bench_futex_wake_usage[] = {
+ "perf bench futex wake <options>",
+ NULL
+};
+
+static void *workerfn(void *arg __maybe_unused)
+{
+ 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);
+
+ futex_wait(&futex1, 0, NULL, FUTEX_PRIVATE_FLAG);
+ return NULL;
+}
+
+static void print_summary(void)
+{
+ double waketime_avg = avg_stats(&waketime_stats);
+ double waketime_stddev = stddev_stats(&waketime_stats);
+ unsigned int wakeup_avg = avg_stats(&wakeup_stats);
+
+ printf("Wokeup %d of %d threads in %.4f ms (+-%.2f%%)\n",
+ wakeup_avg,
+ nthreads,
+ waketime_avg/1e3,
+ rel_stddev_stats(waketime_stddev, waketime_avg));
+}
+
+static void block_threads(pthread_t *w,
+ pthread_attr_t thread_attr)
+{
+ cpu_set_t cpu;
+ unsigned int i;
+
+ threads_starting = nthreads;
+
+ /* create and block all threads */
+ for (i = 0; i < nthreads; i++) {
+ CPU_ZERO(&cpu);
+ CPU_SET(i % ncpus, &cpu);
+
+ if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpu))
+ err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+
+ if (pthread_create(&w[i], &thread_attr, workerfn, NULL))
+ err(EXIT_FAILURE, "pthread_create");
+ }
+}
+
+static void toggle_done(int sig __maybe_unused,
+ siginfo_t *info __maybe_unused,
+ void *uc __maybe_unused)
+{
+ done = true;
+}
+
+int bench_futex_wake(int argc, const char **argv,
+ const char *prefix __maybe_unused)
+{
+ int ret = 0;
+ unsigned int i, j;
+ struct sigaction act;
+ pthread_attr_t thread_attr;
+
+ argc = parse_options(argc, argv, options, bench_futex_wake_usage, 0);
+ if (argc) {
+ usage_with_options(bench_futex_wake_usage, options);
+ exit(EXIT_FAILURE);
+ }
+
+ ncpus = sysconf(_SC_NPROCESSORS_ONLN);
+
+ sigfillset(&act.sa_mask);
+ act.sa_sigaction = toggle_done;
+ sigaction(SIGINT, &act, NULL);
+
+ if (!nthreads)
+ nthreads = ncpus;
+
+ worker = calloc(nthreads, sizeof(*worker));
+ if (!worker)
+ err(EXIT_FAILURE, "calloc");
+
+ printf("Run summary [PID %d]: blocking on %d threads (at futex %p), "
+ "waking up %d at a time.\n\n",
+ getpid(), nthreads, &futex1, nwakes);
+
+ init_stats(&wakeup_stats);
+ init_stats(&waketime_stats);
+ pthread_attr_init(&thread_attr);
+ pthread_mutex_init(&thread_lock, NULL);
+ pthread_cond_init(&thread_parent, NULL);
+ pthread_cond_init(&thread_worker, NULL);
+
+ for (j = 0; j < repeat && !done; j++) {
+ unsigned int nwoken = 0;
+ struct timeval start, end, runtime;
+
+ /* create, launch & block all threads */
+ block_threads(worker, thread_attr);
+
+ /* make sure all threads are already blocked */
+ 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);
+
+ usleep(100000);
+
+ /* Ok, all threads are patiently blocked, start waking folks up */
+ gettimeofday(&start, NULL);
+ while (nwoken != nthreads)
+ nwoken += futex_wake(&futex1, nwakes, FUTEX_PRIVATE_FLAG);
+ gettimeofday(&end, NULL);
+ timersub(&end, &start, &runtime);
+
+ update_stats(&wakeup_stats, nwoken);
+ update_stats(&waketime_stats, runtime.tv_usec);
+
+ if (!silent) {
+ printf("[Run %d]: Wokeup %d of %d threads in %.4f ms\n",
+ j + 1, nwoken, nthreads, runtime.tv_usec/1e3);
+ }
+
+ for (i = 0; i < nthreads; i++) {
+ ret = pthread_join(worker[i], 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);
+ pthread_attr_destroy(&thread_attr);
+
+ print_summary();
+
+ free(worker);
+ return ret;
+}
diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h
new file mode 100644
index 000000000000..71f2844cf97f
--- /dev/null
+++ b/tools/perf/bench/futex.h
@@ -0,0 +1,71 @@
+/*
+ * Glibc independent futex library for testing kernel functionality.
+ * Shamelessly stolen from Darren Hart <dvhltc@us.ibm.com>
+ * http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git/
+ */
+
+#ifndef _FUTEX_H
+#define _FUTEX_H
+
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <linux/futex.h>
+
+/**
+ * futex() - SYS_futex syscall wrapper
+ * @uaddr: address of first futex
+ * @op: futex op code
+ * @val: typically expected value of uaddr, but varies by op
+ * @timeout: typically an absolute struct timespec (except where noted
+ * otherwise). Overloaded by some ops
+ * @uaddr2: address of second futex for some ops\
+ * @val3: varies by op
+ * @opflags: flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG
+ *
+ * futex() is used by all the following futex op wrappers. It can also be
+ * used for misuse and abuse testing. Generally, the specific op wrappers
+ * should be used instead. It is a macro instead of an static inline function as
+ * some of the types over overloaded (timeout is used for nr_requeue for
+ * example).
+ *
+ * These argument descriptions are the defaults for all
+ * like-named arguments in the following wrappers except where noted below.
+ */
+#define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \
+ syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3)
+
+/**
+ * futex_wait() - block on uaddr with optional timeout
+ * @timeout: relative timeout
+ */
+static inline int
+futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags)
+{
+ return futex(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags);
+}
+
+/**
+ * futex_wake() - wake one or more tasks blocked on uaddr
+ * @nr_wake: wake up to this many tasks
+ */
+static inline int
+futex_wake(u_int32_t *uaddr, int nr_wake, int opflags)
+{
+ return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags);
+}
+
+/**
+* futex_cmp_requeue() - requeue tasks from uaddr to uaddr2
+* @nr_wake: wake up to this many tasks
+* @nr_requeue: requeue up to this many tasks
+*/
+static inline int
+futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake,
+ int nr_requeue, int opflags)
+{
+ return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
+ val, opflags);
+}
+
+#endif /* _FUTEX_H */