scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 319 insertions, 0 deletions

diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
new file mode 100644
index 000000000..0748b0fd6
--- /dev/null
+++ b/tools/perf/bench/futex-requeue.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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 (in the non-pi case) -- thus
+ * mimicking a regular futex_wait.
+ */
+
+/* For the CLR_() macros */
+#include <string.h>
+#include <pthread.h>
+
+#include <signal.h>
+#include "../util/mutex.h"
+#include "../util/stat.h"
+#include <subcmd/parse-options.h>
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/time64.h>
+#include <errno.h>
+#include <perf/cpumap.h>
+#include "bench.h"
+#include "futex.h"
+
+#include <err.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <sys/mman.h>
+
+static u_int32_t futex1 = 0, futex2 = 0;
+
+static pthread_t *worker;
+static bool done = false;
+static struct mutex thread_lock;
+static struct cond thread_parent, thread_worker;
+static struct stats requeuetime_stats, requeued_stats;
+static unsigned int threads_starting;
+static int futex_flag = 0;
+
+static struct bench_futex_parameters params = {
+	.nbuckets = -1,
+	/*
+	 * How many tasks to requeue at a time.
+	 * Default to 1 in order to make the kernel work more.
+	 */
+	.nrequeue = 1,
+};
+
+static const struct option options[] = {
+	OPT_INTEGER( 'b', "buckets", &params.nbuckets, "Specify amount of hash buckets"),
+	OPT_UINTEGER('t', "threads",  &params.nthreads, "Specify amount of threads"),
+	OPT_UINTEGER('q', "nrequeue", &params.nrequeue, "Specify amount of threads to requeue at once"),
+	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_BOOLEAN( 'B', "broadcast", &params.broadcast, "Requeue all threads at once"),
+	OPT_BOOLEAN( 'p', "pi", &params.pi, "Use PI-aware variants of FUTEX_CMP_REQUEUE"),
+
+	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,
+	       params.nthreads,
+	       requeuetime_avg / USEC_PER_MSEC,
+	       rel_stddev_stats(requeuetime_stddev, requeuetime_avg));
+	futex_print_nbuckets(&params);
+}
+
+static void *workerfn(void *arg __maybe_unused)
+{
+	int ret;
+
+	mutex_lock(&thread_lock);
+	threads_starting--;
+	if (!threads_starting)
+		cond_signal(&thread_parent);
+	cond_wait(&thread_worker, &thread_lock);
+	mutex_unlock(&thread_lock);
+
+	while (1) {
+		if (!params.pi) {
+			ret = futex_wait(&futex1, 0, NULL, futex_flag);
+			if (!ret)
+				break;
+
+			if (ret && errno != EAGAIN) {
+				if (!params.silent)
+					warnx("futex_wait");
+				break;
+			}
+		} else {
+			ret = futex_wait_requeue_pi(&futex1, 0, &futex2,
+						    NULL, futex_flag);
+			if (!ret) {
+				/* got the lock at futex2 */
+				futex_unlock_pi(&futex2, futex_flag);
+				break;
+			}
+
+			if (ret && errno != EAGAIN) {
+				if (!params.silent)
+					warnx("futex_wait_requeue_pi");
+				break;
+			}
+		}
+	}
+
+	return NULL;
+}
+
+static void block_threads(pthread_t *w, struct perf_cpu_map *cpu)
+{
+	cpu_set_t *cpuset;
+	unsigned int i;
+	int nrcpus = cpu__max_cpu().cpu;
+	size_t size;
+
+	threads_starting = params.nthreads;
+
+	cpuset = CPU_ALLOC(nrcpus);
+	BUG_ON(!cpuset);
+	size = CPU_ALLOC_SIZE(nrcpus);
+
+	/* create and block all threads */
+	for (i = 0; i < params.nthreads; i++) {
+		pthread_attr_t thread_attr;
+
+		pthread_attr_init(&thread_attr);
+		CPU_ZERO_S(size, cpuset);
+		CPU_SET_S(perf_cpu_map__cpu(cpu, i % perf_cpu_map__nr(cpu)).cpu, size, cpuset);
+
+		if (pthread_attr_setaffinity_np(&thread_attr, size, cpuset)) {
+			CPU_FREE(cpuset);
+			err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+		}
+
+		if (pthread_create(&w[i], &thread_attr, workerfn, NULL)) {
+			CPU_FREE(cpuset);
+			err(EXIT_FAILURE, "pthread_create");
+		}
+		pthread_attr_destroy(&thread_attr);
+	}
+	CPU_FREE(cpuset);
+}
+
+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)
+{
+	int ret = 0;
+	unsigned int i, j;
+	struct sigaction act;
+	struct perf_cpu_map *cpu;
+
+	argc = parse_options(argc, argv, options, bench_futex_requeue_usage, 0);
+	if (argc)
+		goto err;
+
+	cpu = perf_cpu_map__new_online_cpus();
+	if (!cpu)
+		err(EXIT_FAILURE, "cpu_map__new");
+
+	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");
+	}
+
+	if (!params.nthreads)
+		params.nthreads = perf_cpu_map__nr(cpu);
+
+	worker = calloc(params.nthreads, sizeof(*worker));
+	if (!worker)
+		err(EXIT_FAILURE, "calloc");
+
+	if (!params.fshared)
+		futex_flag = FUTEX_PRIVATE_FLAG;
+
+	if (params.nrequeue > params.nthreads)
+		params.nrequeue = params.nthreads;
+
+	if (params.broadcast)
+		params.nrequeue = params.nthreads;
+
+	futex_set_nbuckets_param(&params);
+
+	printf("Run summary [PID %d]: Requeuing %d threads (from [%s] %p to %s%p), "
+	       "%d at a time.\n\n",  getpid(), params.nthreads,
+	       params.fshared ? "shared":"private", &futex1,
+	       params.pi ? "PI ": "", &futex2, params.nrequeue);
+
+	init_stats(&requeued_stats);
+	init_stats(&requeuetime_stats);
+	mutex_init(&thread_lock);
+	cond_init(&thread_parent);
+	cond_init(&thread_worker);
+
+	for (j = 0; j < bench_repeat && !done; j++) {
+		unsigned int nrequeued = 0, wakeups = 0;
+		struct timeval start, end, runtime;
+
+		/* create, launch & block all threads */
+		block_threads(worker, cpu);
+
+		/* make sure all threads are already blocked */
+		mutex_lock(&thread_lock);
+		while (threads_starting)
+			cond_wait(&thread_parent, &thread_lock);
+		cond_broadcast(&thread_worker);
+		mutex_unlock(&thread_lock);
+
+		usleep(100000);
+
+		/* Ok, all threads are patiently blocked, start requeueing */
+		gettimeofday(&start, NULL);
+		while (nrequeued < params.nthreads) {
+			int r;
+
+			/*
+			 * For the regular non-pi case, do not wakeup any tasks
+			 * blocked on futex1, allowing us to really measure
+			 * futex_wait functionality. For the PI case the first
+			 * waiter is always awoken.
+			 */
+			if (!params.pi) {
+				r = futex_cmp_requeue(&futex1, 0, &futex2, 0,
+						      params.nrequeue,
+						      futex_flag);
+			} else {
+				r = futex_cmp_requeue_pi(&futex1, 0, &futex2,
+							 params.nrequeue,
+							 futex_flag);
+				wakeups++; /* assume no error */
+			}
+
+			if (r < 0)
+				err(EXIT_FAILURE, "couldn't requeue from %p to %p",
+				    &futex1, &futex2);
+
+			nrequeued += r;
+		}
+
+		gettimeofday(&end, NULL);
+		timersub(&end, &start, &runtime);
+
+		update_stats(&requeued_stats, nrequeued);
+		update_stats(&requeuetime_stats, runtime.tv_usec);
+
+		if (!params.silent) {
+			if (!params.pi)
+				printf("[Run %d]: Requeued %d of %d threads in "
+				       "%.4f ms\n", j + 1, nrequeued,
+				       params.nthreads,
+				       runtime.tv_usec / (double)USEC_PER_MSEC);
+			else {
+				nrequeued -= wakeups;
+				printf("[Run %d]: Awoke and Requeued (%d+%d) of "
+				       "%d threads in %.4f ms\n",
+				       j + 1, wakeups, nrequeued,
+				       params.nthreads,
+				       runtime.tv_usec / (double)USEC_PER_MSEC);
+			}
+
+		}
+
+		if (!params.pi) {
+			/* everybody should be blocked on futex2, wake'em up */
+			nrequeued = futex_wake(&futex2, nrequeued, futex_flag);
+			if (params.nthreads != nrequeued)
+				warnx("couldn't wakeup all tasks (%d/%d)",
+				      nrequeued, params.nthreads);
+		}
+
+		for (i = 0; i < params.nthreads; i++) {
+			ret = pthread_join(worker[i], NULL);
+			if (ret)
+				err(EXIT_FAILURE, "pthread_join");
+		}
+	}
+
+	/* cleanup & report results */
+	cond_destroy(&thread_parent);
+	cond_destroy(&thread_worker);
+	mutex_destroy(&thread_lock);
+
+	print_summary();
+
+	free(worker);
+	perf_cpu_map__put(cpu);
+	return ret;
+err:
+	usage_with_options(bench_futex_requeue_usage, options);
+	exit(EXIT_FAILURE);
+}