[PATCH 1/3] selftests/powerpc: Count instructions under scheduler pressure

[Michael Ellerman]

Have a task eat some cpu while we are counting instructions to create
some scheduler pressure. The idea being to try and unearth any bugs we
have in counting that only appear when context switching is happening.

Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
 tools/testing/selftests/powerpc/pmu/Makefile             | 2 +-
 tools/testing/selftests/powerpc/pmu/count_instructions.c | 8 +++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/powerpc/pmu/Makefile b/tools/testing/selftests/powerpc/pmu/Makefile
index b9ff0db42c79..9c1ae4a9aa53 100644
--- a/tools/testing/selftests/powerpc/pmu/Makefile
+++ b/tools/testing/selftests/powerpc/pmu/Makefile
@@ -2,7 +2,7 @@ noarg:
 	$(MAKE) -C ../
 
 PROGS := count_instructions
-EXTRA_SOURCES := ../harness.c event.c
+EXTRA_SOURCES := ../harness.c event.c lib.c
 
 all: $(PROGS) sub_all
 
diff --git a/tools/testing/selftests/powerpc/pmu/count_instructions.c b/tools/testing/selftests/powerpc/pmu/count_instructions.c
index 312b4f0fd27c..5e241e14f204 100644
--- a/tools/testing/selftests/powerpc/pmu/count_instructions.c
+++ b/tools/testing/selftests/powerpc/pmu/count_instructions.c
@@ -12,6 +12,7 @@
 
 #include "event.h"
 #include "utils.h"
+#include "lib.h"
 
 extern void thirty_two_instruction_loop(u64 loops);
 
@@ -90,7 +91,7 @@ static u64 determine_overhead(struct event *events)
 	return overhead;
 }
 
-static int count_instructions(void)
+static int test_body(void)
 {
 	struct event events[2];
 	u64 overhead;
@@ -129,6 +130,11 @@ static int count_instructions(void)
 	return 0;
 }
 
+static int count_instructions(void)
+{
+	return eat_cpu(test_body);
+}
+
 int main(void)
 {
 	return test_harness(count_instructions, "count_instructions");
-- 
1.9.1