Re: [PATCH v3] selftests/ftrace: Do not trace do_softirq because of PREEMPT_RT

From: Sebastian Andrzej Siewior
Date: Mon Feb 14 2022 - 06:33:52 EST


On 2022-02-14 09:36:57 [+0100], Krzysztof Kozlowski wrote:
> 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>
> Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

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

Yes, and now it does not sound (to me) like duct tape. Thank you.

> If it is not suitable alone, please consider it for RT patchset.

We trying to get it merged so…

Sebastian