[PATCH 6.1 301/473] perf test: Add sqrtloop test workload

Greg Kroah-Hartman
2024-06-06T14:16:58Z

From: Namhyung Kim <namhyung@kernel.org>

[ Upstream commit 39281709a6e2301ac4c6ac7015c7793392ca2dfe ]

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).

Committer notes:

Explicitely ignored the sqrt() return to fix the build on systems where
the compiler complains it isn't being used.

And added a sqrtloop specific CFLAGS to disable optimizations to make
this a bit more robust wrt dead code elimination.

Doing that a -U_FORTIFY_SOURCE needs to be added, as -O0 is incompatible
with it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20221116233854.1596378-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Stable-dep-of: 256ef072b384 ("perf tests: Make "test data symbol" more robust on Neoverse N1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/tests/builtin-test.c | 1 +
tools/perf/tests/tests.h | 1 +
tools/perf/tests/workloads/Build | 2 ++
tools/perf/tests/workloads/sqrtloop.c | 45 +++++++++++++++++++++++++++
4 files changed, 49 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 0ed5ac452f6ee..9acb7a93eeb97 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 86804dd6452b7..18c40319e67c7 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 03dc675a4a7c8..2312a338f01c0 100644
--- a/tools/perf/tests/workloads/Build
+++ b/tools/perf/tests/workloads/Build
@@ -3,5 +3,7 @@
perf-y += noploop.o
perf-y += thloop.o
perf-y += leafloop.o
+perf-y += sqrtloop.o

+CFLAGS_sqrtloop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE
CFLAGS_leafloop.o = -g -O0 -fno-inline -fno-omit-frame-pointer -U_FORTIFY_SOURCE
diff --git a/tools/perf/tests/workloads/sqrtloop.c b/tools/perf/tests/workloads/sqrtloop.c
new file mode 100644
index 0000000000000..ccc94c6a6676a
--- /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)
+ (void)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);
--
2.43.0