From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- tools/perf/bench/futex-hash.c | 227 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 tools/perf/bench/futex-hash.c (limited to 'tools/perf/bench/futex-hash.c') diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c new file mode 100644 index 000000000..ee9b28065 --- /dev/null +++ b/tools/perf/bench/futex-hash.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2013 Davidlohr Bueso + * + * 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 +#include + +#include +#include +#include +#include +#include +#include + +#include "../util/stat.h" +#include +#include "bench.h" +#include "futex.h" +#include "cpumap.h" + +#include + +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 bench__start, bench__end, bench__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 ", + 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(&bench__end, NULL); + timersub(&bench__end, &bench__start, &bench__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)bench__runtime.tv_sec); +} + +int bench_futex_hash(int argc, const char **argv) +{ + int ret = 0; + cpu_set_t cpuset; + struct sigaction act; + unsigned int i; + pthread_attr_t thread_attr; + struct worker *worker = NULL; + struct cpu_map *cpu; + + argc = parse_options(argc, argv, options, bench_futex_hash_usage, 0); + if (argc) { + usage_with_options(bench_futex_hash_usage, options); + exit(EXIT_FAILURE); + } + + cpu = cpu_map__new(NULL); + if (!cpu) + goto errmem; + + sigfillset(&act.sa_mask); + act.sa_sigaction = toggle_done; + sigaction(SIGINT, &act, NULL); + + if (!nthreads) /* default to the number of CPUs */ + nthreads = cpu->nr; + + 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(&bench__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(&cpuset); + CPU_SET(cpu->map[i % cpu->nr], &cpuset); + + ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset); + 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 / bench__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); + free(cpu); + return ret; +errmem: + err(EXIT_FAILURE, "calloc"); +} -- cgit v1.2.3