[PATCH 07/12] perf test: Add 'sqrtloop' test workload

[Namhyung Kim <namhyung@kernel.org>]

The sqrtloop creates a child process to run an infinite loop calling
sqrt() with rand().  This is needed for ARM SPE fork test.

  $ perf test -w sqrtloop

It can take an optional argument to specify how long it will run in
seconds (default: 1).

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/tests/builtin-test.c       |  1 +
 tools/perf/tests/tests.h              |  1 +
 tools/perf/tests/workloads/Build      |  1 +
 tools/perf/tests/workloads/sqrtloop.c | 45 +++++++++++++++++++++++++++
 4 files changed, 48 insertions(+)
 create mode 100644 tools/perf/tests/workloads/sqrtloop.c

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 0ed5ac452f6e..9acb7a93eeb9 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -122,6 +122,7 @@ static struct test_workload *workloads[] = {
 	&workload__noploop,
 	&workload__thloop,
 	&workload__leafloop,
+	&workload__sqrtloop,
 };
 
 static int num_subtests(const struct test_suite *t)
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 86804dd6452b..18c40319e67c 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -203,5 +203,6 @@ struct test_workload workload__##work = {	\
 DECLARE_WORKLOAD(noploop);
 DECLARE_WORKLOAD(thloop);
 DECLARE_WORKLOAD(leafloop);
+DECLARE_WORKLOAD(sqrtloop);
 
 #endif /* TESTS_H */
diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
index 631596bdb2b3..1ca95cb0fdb5 100644
--- a/tools/perf/tests/workloads/Build
+++ b/tools/perf/tests/workloads/Build
@@ -3,5 +3,6 @@
 perf-y += noploop.o
 perf-y += thloop.o
 perf-y += leafloop.o
+perf-y += sqrtloop.o
 
 CFLAGS_leafloop.o         = -g -O0 -fno-inline -fno-omit-frame-pointer
diff --git a/tools/perf/tests/workloads/sqrtloop.c b/tools/perf/tests/workloads/sqrtloop.c
new file mode 100644
index 000000000000..1e44d541d737
--- /dev/null
+++ b/tools/perf/tests/workloads/sqrtloop.c
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <math.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/compiler.h>
+#include <sys/wait.h>
+#include "../tests.h"
+
+static volatile sig_atomic_t done;
+
+static void sighandler(int sig __maybe_unused)
+{
+	done = 1;
+}
+
+static int __sqrtloop(int sec)
+{
+	signal(SIGALRM, sighandler);
+	alarm(sec);
+
+	while (!done)
+		sqrt(rand());
+	return 0;
+}
+
+static int sqrtloop(int argc, const char **argv)
+{
+	int sec = 1;
+
+	if (argc > 0)
+		sec = atoi(argv[0]);
+
+	switch (fork()) {
+	case 0:
+		return __sqrtloop(sec);
+	case -1:
+		return -1;
+	default:
+		wait(NULL);
+	}
+	return 0;
+}
+
+DEFINE_WORKLOAD(sqrtloop);
-- 
2.38.1.493.g58b659f92b-goog