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, 170 insertions, 0 deletions

diff --git a/tools/perf/util/strbuf.c b/tools/perf/util/strbuf.c
new file mode 100644
index 000000000..a64a37628
--- /dev/null
+++ b/tools/perf/util/strbuf.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "cache.h"
+#include "debug.h"
+#include "strbuf.h"
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/zalloc.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/*
+ * Used as the default ->buf value, so that people can always assume
+ * buf is non NULL and ->buf is NUL terminated even for a freshly
+ * initialized strbuf.
+ */
+char strbuf_slopbuf[1];
+
+int strbuf_init(struct strbuf *sb, ssize_t hint)
+{
+	sb->alloc = sb->len = 0;
+	sb->buf = strbuf_slopbuf;
+	if (hint)
+		return strbuf_grow(sb, hint);
+	return 0;
+}
+
+void strbuf_release(struct strbuf *sb)
+{
+	if (sb->alloc) {
+		zfree(&sb->buf);
+		strbuf_init(sb, 0);
+	}
+}
+
+char *strbuf_detach(struct strbuf *sb, size_t *sz)
+{
+	char *res = sb->alloc ? sb->buf : NULL;
+	if (sz)
+		*sz = sb->len;
+	strbuf_init(sb, 0);
+	return res;
+}
+
+int strbuf_grow(struct strbuf *sb, size_t extra)
+{
+	char *buf;
+	size_t nr = sb->len + extra + 1;
+
+	if (nr < sb->alloc)
+		return 0;
+
+	if (nr <= sb->len)
+		return -E2BIG;
+
+	if (alloc_nr(sb->alloc) > nr)
+		nr = alloc_nr(sb->alloc);
+
+	/*
+	 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
+	 * a static variable. Thus we have to avoid passing it to realloc.
+	 */
+	buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
+	if (!buf)
+		return -ENOMEM;
+
+	sb->buf = buf;
+	sb->alloc = nr;
+	return 0;
+}
+
+int strbuf_addch(struct strbuf *sb, int c)
+{
+	int ret = strbuf_grow(sb, 1);
+	if (ret)
+		return ret;
+
+	sb->buf[sb->len++] = c;
+	sb->buf[sb->len] = '\0';
+	return 0;
+}
+
+int strbuf_add(struct strbuf *sb, const void *data, size_t len)
+{
+	int ret = strbuf_grow(sb, len);
+	if (ret)
+		return ret;
+
+	memcpy(sb->buf + sb->len, data, len);
+	return strbuf_setlen(sb, sb->len + len);
+}
+
+static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
+{
+	int len, ret;
+	va_list ap_saved;
+
+	if (!strbuf_avail(sb)) {
+		ret = strbuf_grow(sb, 64);
+		if (ret)
+			return ret;
+	}
+
+	va_copy(ap_saved, ap);
+	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
+	if (len < 0) {
+		va_end(ap_saved);
+		return len;
+	}
+	if (len > strbuf_avail(sb)) {
+		ret = strbuf_grow(sb, len);
+		if (ret) {
+			va_end(ap_saved);
+			return ret;
+		}
+		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
+		if (len > strbuf_avail(sb)) {
+			pr_debug("this should not happen, your vsnprintf is broken");
+			va_end(ap_saved);
+			return -EINVAL;
+		}
+	}
+	va_end(ap_saved);
+	return strbuf_setlen(sb, sb->len + len);
+}
+
+int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = strbuf_addv(sb, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
+{
+	size_t oldlen = sb->len;
+	size_t oldalloc = sb->alloc;
+	int ret;
+
+	ret = strbuf_grow(sb, hint ? hint : 8192);
+	if (ret)
+		return ret;
+
+	for (;;) {
+		ssize_t cnt;
+
+		cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
+		if (cnt < 0) {
+			if (oldalloc == 0)
+				strbuf_release(sb);
+			else
+				strbuf_setlen(sb, oldlen);
+			return cnt;
+		}
+		if (!cnt)
+			break;
+		sb->len += cnt;
+		ret = strbuf_grow(sb, 8192);
+		if (ret)
+			return ret;
+	}
+
+	sb->buf[sb->len] = '\0';
+	return sb->len - oldlen;
+}