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3b2323c2c1
It was reported that the whole futex bench breaks when dealing with non-contiguously numbered cpus. $ echo 0 | sudo tee /sys/devices/system/cpu/cpu3/online $ ./perf bench futex all perf: pthread_create: Operation not permitted Run summary [PID 14934]: 7 threads, each .... James had implemented an approach with cpumaps that use an in house flavor. Instead of re-inventing the wheel, I've redone the patch such that we use the perf's util/cpumap.c interface instead. Applies to all futex benchmarks. Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Originally-from: James Yang <james.yang@arm.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Kim Phillips <kim.phillips@arm.com> Link: http://lkml.kernel.org/r/20171127042101.3659-2-dave@stgolabs.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
231 lines
5.5 KiB
C
231 lines
5.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2015 Davidlohr Bueso.
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*/
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/* For the CLR_() macros */
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#include <string.h>
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#include <pthread.h>
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#include <signal.h>
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#include "../util/stat.h"
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#include <subcmd/parse-options.h>
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#include <linux/compiler.h>
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#include <linux/kernel.h>
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#include <errno.h>
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#include "bench.h"
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#include "futex.h"
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#include "cpumap.h"
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#include <err.h>
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#include <stdlib.h>
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#include <sys/time.h>
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struct worker {
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int tid;
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u_int32_t *futex;
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pthread_t thread;
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unsigned long ops;
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};
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static u_int32_t global_futex = 0;
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static struct worker *worker;
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static unsigned int nsecs = 10;
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static bool silent = false, multi = false;
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static bool done = false, fshared = false;
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static unsigned int nthreads = 0;
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static int futex_flag = 0;
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struct timeval start, end, runtime;
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static pthread_mutex_t thread_lock;
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static unsigned int threads_starting;
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static struct stats throughput_stats;
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static pthread_cond_t thread_parent, thread_worker;
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static const struct option options[] = {
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OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
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OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"),
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OPT_BOOLEAN( 'M', "multi", &multi, "Use multiple futexes"),
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OPT_BOOLEAN( 's', "silent", &silent, "Silent mode: do not display data/details"),
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OPT_BOOLEAN( 'S', "shared", &fshared, "Use shared futexes instead of private ones"),
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OPT_END()
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};
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static const char * const bench_futex_lock_pi_usage[] = {
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"perf bench futex lock-pi <options>",
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NULL
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};
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static void print_summary(void)
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{
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unsigned long avg = avg_stats(&throughput_stats);
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double stddev = stddev_stats(&throughput_stats);
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printf("%sAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n",
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!silent ? "\n" : "", avg, rel_stddev_stats(stddev, avg),
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(int) runtime.tv_sec);
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}
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static void toggle_done(int sig __maybe_unused,
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siginfo_t *info __maybe_unused,
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void *uc __maybe_unused)
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{
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/* inform all threads that we're done for the day */
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done = true;
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gettimeofday(&end, NULL);
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timersub(&end, &start, &runtime);
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}
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static void *workerfn(void *arg)
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{
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struct worker *w = (struct worker *) arg;
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unsigned long ops = w->ops;
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pthread_mutex_lock(&thread_lock);
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threads_starting--;
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if (!threads_starting)
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pthread_cond_signal(&thread_parent);
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pthread_cond_wait(&thread_worker, &thread_lock);
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pthread_mutex_unlock(&thread_lock);
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do {
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int ret;
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again:
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ret = futex_lock_pi(w->futex, NULL, futex_flag);
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if (ret) { /* handle lock acquisition */
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if (!silent)
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warn("thread %d: Could not lock pi-lock for %p (%d)",
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w->tid, w->futex, ret);
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if (done)
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break;
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goto again;
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}
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usleep(1);
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ret = futex_unlock_pi(w->futex, futex_flag);
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if (ret && !silent)
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warn("thread %d: Could not unlock pi-lock for %p (%d)",
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w->tid, w->futex, ret);
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ops++; /* account for thread's share of work */
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} while (!done);
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w->ops = ops;
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return NULL;
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}
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static void create_threads(struct worker *w, pthread_attr_t thread_attr,
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struct cpu_map *cpu)
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{
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cpu_set_t cpuset;
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unsigned int i;
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threads_starting = nthreads;
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for (i = 0; i < nthreads; i++) {
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worker[i].tid = i;
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if (multi) {
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worker[i].futex = calloc(1, sizeof(u_int32_t));
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if (!worker[i].futex)
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err(EXIT_FAILURE, "calloc");
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} else
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worker[i].futex = &global_futex;
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CPU_ZERO(&cpuset);
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CPU_SET(cpu->map[i % cpu->nr], &cpuset);
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if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
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err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
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if (pthread_create(&w[i].thread, &thread_attr, workerfn, &worker[i]))
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err(EXIT_FAILURE, "pthread_create");
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}
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}
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int bench_futex_lock_pi(int argc, const char **argv)
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{
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int ret = 0;
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unsigned int i;
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struct sigaction act;
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pthread_attr_t thread_attr;
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struct cpu_map *cpu;
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argc = parse_options(argc, argv, options, bench_futex_lock_pi_usage, 0);
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if (argc)
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goto err;
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cpu = cpu_map__new(NULL);
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if (!cpu)
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err(EXIT_FAILURE, "calloc");
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sigfillset(&act.sa_mask);
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act.sa_sigaction = toggle_done;
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sigaction(SIGINT, &act, NULL);
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if (!nthreads)
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nthreads = cpu->nr;
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worker = calloc(nthreads, sizeof(*worker));
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if (!worker)
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err(EXIT_FAILURE, "calloc");
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if (!fshared)
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futex_flag = FUTEX_PRIVATE_FLAG;
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printf("Run summary [PID %d]: %d threads doing pi lock/unlock pairing for %d secs.\n\n",
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getpid(), nthreads, nsecs);
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init_stats(&throughput_stats);
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pthread_mutex_init(&thread_lock, NULL);
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pthread_cond_init(&thread_parent, NULL);
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pthread_cond_init(&thread_worker, NULL);
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threads_starting = nthreads;
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pthread_attr_init(&thread_attr);
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gettimeofday(&start, NULL);
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create_threads(worker, thread_attr, cpu);
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pthread_attr_destroy(&thread_attr);
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pthread_mutex_lock(&thread_lock);
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while (threads_starting)
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pthread_cond_wait(&thread_parent, &thread_lock);
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pthread_cond_broadcast(&thread_worker);
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pthread_mutex_unlock(&thread_lock);
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sleep(nsecs);
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toggle_done(0, NULL, NULL);
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for (i = 0; i < nthreads; i++) {
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ret = pthread_join(worker[i].thread, NULL);
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if (ret)
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err(EXIT_FAILURE, "pthread_join");
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}
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/* cleanup & report results */
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pthread_cond_destroy(&thread_parent);
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pthread_cond_destroy(&thread_worker);
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pthread_mutex_destroy(&thread_lock);
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for (i = 0; i < nthreads; i++) {
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unsigned long t = worker[i].ops/runtime.tv_sec;
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update_stats(&throughput_stats, t);
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if (!silent)
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printf("[thread %3d] futex: %p [ %ld ops/sec ]\n",
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worker[i].tid, worker[i].futex, t);
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if (multi)
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free(worker[i].futex);
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}
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print_summary();
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free(worker);
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return ret;
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err:
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usage_with_options(bench_futex_lock_pi_usage, options);
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exit(EXIT_FAILURE);
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}
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