[PATCH v2 05/18] perf test: Add deterministic workload

[James Clark]

Add a workload that does the same thing every time for testing CPU trace
decoding.

Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
---
 tools/perf/Documentation/perf-test.txt     |  4 +--
 tools/perf/tests/builtin-test.c            |  1 +
 tools/perf/tests/tests.h                   |  1 +
 tools/perf/tests/workloads/Build           |  2 ++
 tools/perf/tests/workloads/deterministic.c | 39 ++++++++++++++++++++++++++++++
 5 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-test.txt b/tools/perf/Documentation/perf-test.txt
index 9c0d7ac2bc64..7ec70c054cac 100644
--- a/tools/perf/Documentation/perf-test.txt
+++ b/tools/perf/Documentation/perf-test.txt
@@ -57,7 +57,7 @@ OPTIONS
 --workload=::
 	Run a built-in workload, to list them use '--list-workloads', current
 	ones include: noploop, thloop, leafloop, sqrtloop, brstack, datasym,
-	context_switch_loop and landlock.
+	context_switch_loop, deterministic and landlock.
 
 	Used with the shell script regression tests.
 
@@ -66,7 +66,7 @@ OPTIONS
 		seconds: leafloop, noploop, sqrtloop, thloop
 		nrloops: brstack, context_switch_loop
 
-	The datasym and landlock workloads don't accept any.
+	The datasym, landlock and deterministic workloads don't accept any.
 
 --list-workloads::
 	List the available workloads to use with -w/--workload.
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 1057ee836c30..3c6d3de98be9 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -157,6 +157,7 @@ static struct test_workload *workloads[] = {
 	&workload__traploop,
 	&workload__inlineloop,
 	&workload__context_switch_loop,
+	&workload__deterministic,
 
 #ifdef HAVE_RUST_SUPPORT
 	&workload__code_with_type,
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 79f50bacfc94..f8bba2d68769 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -243,6 +243,7 @@ DECLARE_WORKLOAD(landlock);
 DECLARE_WORKLOAD(traploop);
 DECLARE_WORKLOAD(inlineloop);
 DECLARE_WORKLOAD(context_switch_loop);
+DECLARE_WORKLOAD(deterministic);
 
 #ifdef HAVE_RUST_SUPPORT
 DECLARE_WORKLOAD(code_with_type);
diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build
index 3bda6da04a35..599a37c87878 100644
--- a/tools/perf/tests/workloads/Build
+++ b/tools/perf/tests/workloads/Build
@@ -10,6 +10,7 @@ perf-test-y += landlock.o
 perf-test-y += traploop.o
 perf-test-y += inlineloop.o
 perf-test-y += context_switch_loop.o
+perf-test-y += deterministic.o
 
 ifeq ($(CONFIG_RUST_SUPPORT),y)
     perf-test-y += code_with_type.o
@@ -22,3 +23,4 @@ CFLAGS_brstack.o          = -g -O0 -fno-inline -U_FORTIFY_SOURCE
 CFLAGS_datasym.o          = -g -O0 -fno-inline -U_FORTIFY_SOURCE
 CFLAGS_traploop.o         = -g -O0 -fno-inline -U_FORTIFY_SOURCE
 CFLAGS_inlineloop.o       = -g -O2
+CFLAGS_deterministic.o    = -g -O0
diff --git a/tools/perf/tests/workloads/deterministic.c b/tools/perf/tests/workloads/deterministic.c
new file mode 100644
index 000000000000..3caea8564043
--- /dev/null
+++ b/tools/perf/tests/workloads/deterministic.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/compiler.h>
+#include "../tests.h"
+
+int dt_work = 1234;
+
+static noinline void function1(void)
+{
+	dt_work *= 7;
+	dt_work *= 7;
+	dt_work *= 7;
+}
+
+static noinline void function2(void)
+{
+	dt_work *= 7;
+	dt_work *= 7;
+	dt_work *= 7;
+}
+
+static int deterministic(int argc __maybe_unused,
+			 const char **argv __maybe_unused)
+{
+	dt_work *= 7;
+	dt_work *= 7;
+	dt_work *= 7;
+
+	function1();
+
+	dt_work *= 7;
+	dt_work *= 7;
+	dt_work *= 7;
+
+	function2();
+
+	return 0;
+}
+
+DEFINE_WORKLOAD(deterministic);

-- 
2.34.1