linux-stable/tools/perf/bench/futex-wake-parallel.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2015 Davidlohr Bueso.
*
* Block a bunch of threads and let parallel waker threads wakeup an
* equal amount of them. The program output reflects the avg latency
* for each individual thread to service its share of work. Ultimately
* it can be used to measure futex_wake() changes.
*/
#include "bench.h"
#include <linux/compiler.h>
#include "../util/debug.h"
#ifndef HAVE_PTHREAD_BARRIER
int bench_futex_wake_parallel(int argc __maybe_unused, const char **argv __maybe_unused)
{
pr_err("%s: pthread_barrier_t unavailable, disabling this test...\n", __func__);
return 0;
}
#else /* HAVE_PTHREAD_BARRIER */
/* For the CLR_() macros */
#include <string.h>
#include <pthread.h>
#include <signal.h>
#include "../util/stat.h"
#include <subcmd/parse-options.h>
#include <linux/kernel.h>
#include <linux/time64.h>
#include <errno.h>
#include "futex.h"
#include <perf/cpumap.h>
#include <err.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/mman.h>
struct thread_data {
pthread_t worker;
unsigned int nwoken;
struct timeval runtime;
};
static unsigned int nwakes = 1;
/* all threads will block on the same futex -- hash bucket chaos ;) */
static u_int32_t futex = 0;
static pthread_t *blocked_worker;
static bool done = false;
static pthread_mutex_t thread_lock;
static pthread_cond_t thread_parent, thread_worker;
static pthread_barrier_t barrier;
static struct stats waketime_stats, wakeup_stats;
static unsigned int threads_starting;
static int futex_flag = 0;
static struct bench_futex_parameters params;
static const struct option options[] = {
OPT_UINTEGER('t', "threads", &params.nthreads, "Specify amount of threads"),
OPT_UINTEGER('w', "nwakers", &params.nwakes, "Specify amount of waking threads"),
OPT_BOOLEAN( 's', "silent", &params.silent, "Silent mode: do not display data/details"),
OPT_BOOLEAN( 'S', "shared", &params.fshared, "Use shared futexes instead of private ones"),
OPT_BOOLEAN( 'm', "mlockall", &params.mlockall, "Lock all current and future memory"),
OPT_END()
};
static const char * const bench_futex_wake_parallel_usage[] = {
"perf bench futex wake-parallel <options>",
NULL
};
static void *waking_workerfn(void *arg)
{
struct thread_data *waker = (struct thread_data *) arg;
struct timeval start, end;
pthread_barrier_wait(&barrier);
gettimeofday(&start, NULL);
waker->nwoken = futex_wake(&futex, nwakes, futex_flag);
if (waker->nwoken != nwakes)
warnx("couldn't wakeup all tasks (%d/%d)",
waker->nwoken, nwakes);
gettimeofday(&end, NULL);
timersub(&end, &start, &waker->runtime);
pthread_exit(NULL);
return NULL;
}
static void wakeup_threads(struct thread_data *td, pthread_attr_t thread_attr)
{
unsigned int i;
pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_JOINABLE);
pthread_barrier_init(&barrier, NULL, params.nwakes + 1);
/* create and block all threads */
for (i = 0; i < params.nwakes; i++) {
/*
* Thread creation order will impact per-thread latency
* as it will affect the order to acquire the hb spinlock.
* For now let the scheduler decide.
*/
if (pthread_create(&td[i].worker, &thread_attr,
waking_workerfn, (void *)&td[i]))
err(EXIT_FAILURE, "pthread_create");
}
pthread_barrier_wait(&barrier);
for (i = 0; i < params.nwakes; i++)
if (pthread_join(td[i].worker, NULL))
err(EXIT_FAILURE, "pthread_join");
pthread_barrier_destroy(&barrier);
}
static void *blocked_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);
while (1) { /* handle spurious wakeups */
if (futex_wait(&futex, 0, NULL, futex_flag) != EINTR)
break;
}
pthread_exit(NULL);
return NULL;
}
static void block_threads(pthread_t *w, pthread_attr_t thread_attr,
struct perf_cpu_map *cpu)
{
cpu_set_t cpuset;
unsigned int i;
threads_starting = params.nthreads;
/* create and block all threads */
for (i = 0; i < params.nthreads; i++) {
CPU_ZERO(&cpuset);
perf cpumap: Give CPUs their own type A common problem is confusing CPU map indices with the CPU, by wrapping the CPU with a struct then this is avoided. This approach is similar to atomic_t. Committer notes: To make it build with BUILD_BPF_SKEL=1 these files needed the conversions to 'struct perf_cpu' usage: tools/perf/util/bpf_counter.c tools/perf/util/bpf_counter_cgroup.c tools/perf/util/bpf_ftrace.c Also perf_env__get_cpu() was removed back in "perf cpumap: Switch cpu_map__build_map to cpu function". Additionally these needed to be fixed for the ARM builds to complete: tools/perf/arch/arm/util/cs-etm.c tools/perf/arch/arm64/util/pmu.c Suggested-by: John Garry <john.garry@huawei.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@arm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Clarke <pc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: Vineet Singh <vineet.singh@intel.com> Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Cc: zhengjun.xing@intel.com Link: https://lore.kernel.org/r/20220105061351.120843-49-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-01-05 06:13:51 +00:00
CPU_SET(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, &cpuset);
if (pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset))
err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
if (pthread_create(&w[i], &thread_attr, blocked_workerfn, NULL))
err(EXIT_FAILURE, "pthread_create");
}
}
static void print_run(struct thread_data *waking_worker, unsigned int run_num)
{
unsigned int i, wakeup_avg;
double waketime_avg, waketime_stddev;
struct stats __waketime_stats, __wakeup_stats;
init_stats(&__wakeup_stats);
init_stats(&__waketime_stats);
for (i = 0; i < params.nwakes; i++) {
update_stats(&__waketime_stats, waking_worker[i].runtime.tv_usec);
update_stats(&__wakeup_stats, waking_worker[i].nwoken);
}
waketime_avg = avg_stats(&__waketime_stats);
waketime_stddev = stddev_stats(&__waketime_stats);
wakeup_avg = avg_stats(&__wakeup_stats);
printf("[Run %d]: Avg per-thread latency (waking %d/%d threads) "
"in %.4f ms (+-%.2f%%)\n", run_num + 1, wakeup_avg,
params.nthreads, waketime_avg / USEC_PER_MSEC,
rel_stddev_stats(waketime_stddev, waketime_avg));
}
static void print_summary(void)
{
unsigned int wakeup_avg;
double waketime_avg, waketime_stddev;
waketime_avg = avg_stats(&waketime_stats);
waketime_stddev = stddev_stats(&waketime_stats);
wakeup_avg = avg_stats(&wakeup_stats);
printf("Avg per-thread latency (waking %d/%d threads) in %.4f ms (+-%.2f%%)\n",
wakeup_avg,
params.nthreads,
waketime_avg / USEC_PER_MSEC,
rel_stddev_stats(waketime_stddev, waketime_avg));
}
static void do_run_stats(struct thread_data *waking_worker)
{
unsigned int i;
for (i = 0; i < params.nwakes; i++) {
update_stats(&waketime_stats, waking_worker[i].runtime.tv_usec);
update_stats(&wakeup_stats, waking_worker[i].nwoken);
}
}
static void toggle_done(int sig __maybe_unused,
siginfo_t *info __maybe_unused,
void *uc __maybe_unused)
{
done = true;
}
int bench_futex_wake_parallel(int argc, const char **argv)
{
int ret = 0;
unsigned int i, j;
struct sigaction act;
pthread_attr_t thread_attr;
struct thread_data *waking_worker;
struct perf_cpu_map *cpu;
argc = parse_options(argc, argv, options,
bench_futex_wake_parallel_usage, 0);
if (argc) {
usage_with_options(bench_futex_wake_parallel_usage, options);
exit(EXIT_FAILURE);
}
memset(&act, 0, sizeof(act));
sigfillset(&act.sa_mask);
act.sa_sigaction = toggle_done;
sigaction(SIGINT, &act, NULL);
if (params.mlockall) {
if (mlockall(MCL_CURRENT | MCL_FUTURE))
err(EXIT_FAILURE, "mlockall");
}
cpu = perf_cpu_map__new(NULL);
if (!cpu)
err(EXIT_FAILURE, "calloc");
if (!params.nthreads)
perf cpumap: Migrate to libperf cpumap api Switch from directly accessing the perf_cpu_map to using the appropriate libperf API when possible. Using the API simplifies the job of refactoring use of perf_cpu_map. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: André Almeida <andrealmeid@collabora.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: German Gomez <german.gomez@arm.com> Cc: James Clark <james.clark@arm.com> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Garry <john.garry@huawei.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Miaoqian Lin <linmq006@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com> Cc: Song Liu <song@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Yury Norov <yury.norov@gmail.com> Link: http://lore.kernel.org/lkml/20220122045811.3402706-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-01-22 04:58:10 +00:00
params.nthreads = perf_cpu_map__nr(cpu);
/* some sanity checks */
if (params.nwakes > params.nthreads ||
!params.nwakes)
params.nwakes = params.nthreads;
if (params.nthreads % params.nwakes)
errx(EXIT_FAILURE, "Must be perfectly divisible");
/*
* Each thread will wakeup nwakes tasks in
* a single futex_wait call.
*/
nwakes = params.nthreads/params.nwakes;
blocked_worker = calloc(params.nthreads, sizeof(*blocked_worker));
if (!blocked_worker)
err(EXIT_FAILURE, "calloc");
if (!params.fshared)
futex_flag = FUTEX_PRIVATE_FLAG;
printf("Run summary [PID %d]: blocking on %d threads (at [%s] "
"futex %p), %d threads waking up %d at a time.\n\n",
getpid(), params.nthreads, params.fshared ? "shared":"private",
&futex, params.nwakes, 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 < bench_repeat && !done; j++) {
waking_worker = calloc(params.nwakes, sizeof(*waking_worker));
if (!waking_worker)
err(EXIT_FAILURE, "calloc");
/* create, launch & block all threads */
block_threads(blocked_worker, thread_attr, cpu);
/* 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 */
wakeup_threads(waking_worker, thread_attr);
for (i = 0; i < params.nthreads; i++) {
ret = pthread_join(blocked_worker[i], NULL);
if (ret)
err(EXIT_FAILURE, "pthread_join");
}
do_run_stats(waking_worker);
if (!params.silent)
print_run(waking_worker, j);
free(waking_worker);
}
/* 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(blocked_worker);
perf_cpu_map__put(cpu);
return ret;
}
#endif /* HAVE_PTHREAD_BARRIER */