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

[Shuah Khan]

On 2/9/22 9:24 AM, Krzysztof Kozlowski wrote:
> The PREEMPT_RT patchset does not use soft IRQs thus trying to filter for
> do_softirq fails for such kernel:
>
>    echo do_softirq
>    ftracetest: 81: echo: echo: I/O error
>
> Choose some other externally visible function for the test.
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>
>
> ---
>
> 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..1d0c7601865f 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="_printk"
>   
>   ALL_FUNCS="#### all functions enabled ####"
>   

Change looks good to me.

Reviewed-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

thanks,
-- Shuah