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authorIngo Molnar <mingo@kernel.org>2015-05-09 08:10:36 +0200
committerIngo Molnar <mingo@kernel.org>2015-05-09 08:10:36 +0200
commit32b0ed3ae66cd6114f8510161f833f05518c0395 (patch)
treef251ef653105de7fa02f0212c30a40e967fa339f /tools/perf/bench
parentcb307113746b4d184155d2c412e8069aeaa60d42 (diff)
parent76d408498b08447e0f61dfdd611aeb6e8e61ce80 (diff)
downloadlinux-32b0ed3ae66cd6114f8510161f833f05518c0395.tar.gz
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: User visible changes: - 'perf probe' improvements: (Masami Hiramatsu) - Support glob wildcards for function name - Support $params special probe argument: Collect all function arguments - Make --line checks validate C-style function name. - Add --no-inlines option to avoid searching inline functions - Introduce new 'perf bench futex' benchmark: 'wake-parallel', to measure parallel waker threads generating contention for kernel locks (hb->lock). (Davidlohr Bueso) Bug fixes: - Improve 'perf top' to survive much longer on high core count machines, more work needed to refcount more data structures besides 'struct thread' and fix more races. (Arnaldo Carvalho de Melo) Infrastructure changes: - Move barrier.h mb/rmb/wmb API from tools/perf/ to kernel like tools/arch/ hierarchy. (Arnaldo Carvalho de Melo) - Borrow atomic.h from the kernel, initially the x86 implementations with a fallback to gcc intrinsics for the other arches, all the kernel like framework in place for doing arch specific implementations, preferrably cloning what is in the kernel to the greater extent possible. (Arnaldo Carvalho de Melo) - Protect the 'struct thread' lifetime with a reference counter, and protect data structures that contains its instances with a mutex. (Arnaldo Carvalho de Melo - Disable libdw DWARF unwind when built with NO_DWARF (Naveen N. Rao) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/perf/bench')
-rw-r--r--tools/perf/bench/Build1
-rw-r--r--tools/perf/bench/bench.h2
-rw-r--r--tools/perf/bench/futex-wake-parallel.c294
-rw-r--r--tools/perf/bench/futex-wake.c7
4 files changed, 303 insertions, 1 deletions
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index 5ce98023d518..c3ab760e06b4 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -3,6 +3,7 @@ perf-y += sched-pipe.o
perf-y += mem-memcpy.o
perf-y += futex-hash.o
perf-y += futex-wake.o
+perf-y += futex-wake-parallel.o
perf-y += futex-requeue.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 3c4dd44d45cb..70b2f718cc21 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -33,6 +33,8 @@ extern int bench_mem_memcpy(int argc, const char **argv,
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_wake_parallel(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"
diff --git a/tools/perf/bench/futex-wake-parallel.c b/tools/perf/bench/futex-wake-parallel.c
new file mode 100644
index 000000000000..6d8c9fa2a16c
--- /dev/null
+++ b/tools/perf/bench/futex-wake-parallel.c
@@ -0,0 +1,294 @@
+/*
+ * 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 "../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>
+
+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, silent = false, fshared = false;
+static unsigned int nblocked_threads = 0, nwaking_threads = 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;
+static int futex_flag = 0;
+
+static const struct option options[] = {
+ OPT_UINTEGER('t', "threads", &nblocked_threads, "Specify amount of threads"),
+ OPT_UINTEGER('w', "nwakers", &nwaking_threads, "Specify amount of waking 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_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;
+
+ 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);
+
+ /* create and block all threads */
+ for (i = 0; i < nwaking_threads; 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");
+ }
+
+ for (i = 0; i < nwaking_threads; i++)
+ if (pthread_join(td[i].worker, NULL))
+ err(EXIT_FAILURE, "pthread_join");
+}
+
+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)
+{
+ cpu_set_t cpu;
+ unsigned int i;
+
+ threads_starting = nblocked_threads;
+
+ /* create and block all threads */
+ for (i = 0; i < nblocked_threads; 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, 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 < nwaking_threads; 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,
+ nblocked_threads, waketime_avg/1e3,
+ 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,
+ nblocked_threads,
+ waketime_avg/1e3,
+ rel_stddev_stats(waketime_stddev, waketime_avg));
+}
+
+
+static void do_run_stats(struct thread_data *waking_worker)
+{
+ unsigned int i;
+
+ for (i = 0; i < nwaking_threads; 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,
+ const char *prefix __maybe_unused)
+{
+ int ret = 0;
+ unsigned int i, j;
+ struct sigaction act;
+ pthread_attr_t thread_attr;
+ struct thread_data *waking_worker;
+
+ 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);
+ }
+
+ sigfillset(&act.sa_mask);
+ act.sa_sigaction = toggle_done;
+ sigaction(SIGINT, &act, NULL);
+
+ ncpus = sysconf(_SC_NPROCESSORS_ONLN);
+ if (!nblocked_threads)
+ nblocked_threads = ncpus;
+
+ /* some sanity checks */
+ if (nwaking_threads > nblocked_threads || !nwaking_threads)
+ nwaking_threads = nblocked_threads;
+
+ if (nblocked_threads % nwaking_threads)
+ errx(EXIT_FAILURE, "Must be perfectly divisible");
+ /*
+ * Each thread will wakeup nwakes tasks in
+ * a single futex_wait call.
+ */
+ nwakes = nblocked_threads/nwaking_threads;
+
+ blocked_worker = calloc(nblocked_threads, sizeof(*blocked_worker));
+ if (!blocked_worker)
+ err(EXIT_FAILURE, "calloc");
+
+ if (!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(), nblocked_threads, fshared ? "shared":"private",
+ &futex, nwaking_threads, 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(nwaking_threads, sizeof(*waking_worker));
+ if (!waking_worker)
+ err(EXIT_FAILURE, "calloc");
+
+ /* create, launch & block all threads */
+ block_threads(blocked_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 */
+ wakeup_threads(waking_worker, thread_attr);
+
+ for (i = 0; i < nblocked_threads; i++) {
+ ret = pthread_join(blocked_worker[i], NULL);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_join");
+ }
+
+ do_run_stats(waking_worker);
+ if (!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);
+ return ret;
+}
diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
index 929f762be47e..e5e41d3bdce7 100644
--- a/tools/perf/bench/futex-wake.c
+++ b/tools/perf/bench/futex-wake.c
@@ -60,7 +60,12 @@ static void *workerfn(void *arg __maybe_unused)
pthread_cond_wait(&thread_worker, &thread_lock);
pthread_mutex_unlock(&thread_lock);
- futex_wait(&futex1, 0, NULL, futex_flag);
+ while (1) {
+ if (futex_wait(&futex1, 0, NULL, futex_flag) != EINTR)
+ break;
+ }
+
+ pthread_exit(NULL);
return NULL;
}