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, 68 insertions, 0 deletions

diff --git a/tools/perf/util/fncache.c b/tools/perf/util/fncache.c
new file mode 100644
index 000000000..bf9559c55
--- /dev/null
+++ b/tools/perf/util/fncache.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Manage a cache of file names' existence */
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/compiler.h>
+#include "fncache.h"
+#include "hashmap.h"
+
+static struct hashmap *fncache;
+
+static size_t fncache__hash(long key, void *ctx __maybe_unused)
+{
+	return str_hash((const char *)key);
+}
+
+static bool fncache__equal(long key1, long key2, void *ctx __maybe_unused)
+{
+	return strcmp((const char *)key1, (const char *)key2) == 0;
+}
+
+static void fncache__init(void)
+{
+	fncache = hashmap__new(fncache__hash, fncache__equal, /*ctx=*/NULL);
+}
+
+static struct hashmap *fncache__get(void)
+{
+	static pthread_once_t fncache_once = PTHREAD_ONCE_INIT;
+
+	pthread_once(&fncache_once, fncache__init);
+
+	return fncache;
+}
+
+static bool lookup_fncache(const char *name, bool *res)
+{
+	long val;
+
+	if (!hashmap__find(fncache__get(), name, &val))
+		return false;
+
+	*res = (val != 0);
+	return true;
+}
+
+static void update_fncache(const char *name, bool res)
+{
+	char *old_key = NULL, *key = strdup(name);
+
+	if (key) {
+		hashmap__set(fncache__get(), key, res, &old_key, /*old_value*/NULL);
+		free(old_key);
+	}
+}
+
+/* No LRU, only use when bounded in some other way. */
+bool file_available(const char *name)
+{
+	bool res;
+
+	if (lookup_fncache(name, &res))
+		return res;
+	res = access(name, R_OK) == 0;
+	update_fncache(name, res);
+	return res;
+}