[PATCH v3 24/28] selftests/ftrace: Add trace_pipe testcase

[Masami Hiramatsu <mhiramat@kernel.org>]

Add a simple testcase for trace_pipe which can consume
ringbuffer.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 Changes in v3:
 - Run this on an instance too.
---
 .../selftests/ftrace/test.d/00basic/trace_pipe.tc  |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 tools/testing/selftests/ftrace/test.d/00basic/trace_pipe.tc

diff --git a/tools/testing/selftests/ftrace/test.d/00basic/trace_pipe.tc b/tools/testing/selftests/ftrace/test.d/00basic/trace_pipe.tc
new file mode 100644
index 000000000000..5058fbcfd90f
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_pipe.tc
@@ -0,0 +1,16 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: trace_pipe and trace_marker
+# flags: instance
+
+[ ! -f trace_marker ] && exit_unsupported
+
+echo "test input 1" > trace_marker
+
+: "trace interface never consume the ring buffer"
+grep -q "test input 1" trace
+grep -q "test input 1" trace
+
+: "trace interface never consume the ring buffer"
+head -n 1 trace_pipe | grep -q "test input 1"
+! grep -q "test input 1" trace