The PREEMPT_RT patchset does not use do_softirq() function thus trying to filter for do_softirq fails for such kernel:

echo do_softirq ftracetest: 81: echo: echo: I/O error

Choose some other visible function for the test. The function does not have to be actually executed during the test, because it is only testing filter API interface.

Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@canonical.com Reviewed-by: Shuah Khan skhan@linuxfoundation.org Reviewed-by: Steven Rostedt (VMware) rostedt@goodmis.org

---

Changes since v2: 1. Rephrase commit msg, after comments from Sebastian. 2. Add review tag.

Changes since v1: 1. Use scheduler_tick. 2. Add review tag.

Notes: I understand that the failure does not exist on mainline kernel (only with PREEMPT_RT patchset) but the change does not harm it.

If it is not suitable alone, please consider it for RT patchset. --- .../selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc index e96e279e0533..25432b8cd5bd 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc @@ -19,7 +19,7 @@ fail() { # mesg

FILTER=set_ftrace_filter FUNC1="schedule" -FUNC2="do_softirq" +FUNC2="scheduler_tick"

ALL_FUNCS="#### all functions enabled ####"