If the stack tracer (CONFIG_STACK_TRACER) is disabled, the fgraph-filter-stack test blows chunks:
[8] ftrace - function graph filters with stack tracer [FAIL] + reset_tracer + echo nop ./ftracetest: 19: /home/michael/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc: cannot create /proc/sys/kernel/stack_tracer_enabled: Directory nonexistent Fix it by checking if the proc file exists before echoing to it. With the patch applied it fails correctly with: [8] ftrace - function graph filters with stack tracer [UNSUPPORTED] Signed-off-by: Michael Ellerman <m...@ellerman.id.au> --- tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc index c15e018e0220..3b1cf20cf6d8 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-filter-stack.tc @@ -16,7 +16,9 @@ fi do_reset() { reset_tracer - echo 0 > /proc/sys/kernel/stack_tracer_enabled + if [ -e /proc/sys/kernel/stack_tracer_enabled ]; then + echo 0 > /proc/sys/kernel/stack_tracer_enabled + fi enable_tracing clear_trace echo > set_ftrace_filter -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/