This is a note to let you know that I've just added the patch titled selftests/ftrace: Do not trace do_softirq because of PREEMPT_RT to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-ftrace-do-not-trace-do_softirq-because-of-.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 25070613ea3b9bf17ccf41cd0a90717d7928e248 Author: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx> Date: Mon Feb 14 09:36:57 2022 +0100 selftests/ftrace: Do not trace do_softirq because of PREEMPT_RT [ Upstream commit 6fec1ab67f8d60704cc7de64abcfd389ab131542 ] 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@xxxxxxxxxxxxx> Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Reviewed-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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 e96e279e0533a..25432b8cd5bd2 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 ####"