Re: [PATCH] s390: remove unused setup_profiling_timer function

[Geert Uytterhoeven]

Hi Anthony,

Thanks for your patch!

On Fri, 21 Aug 2026 at 08:05, Anthony Iliopoulos <ailiop@xxxxxxxx> wrote:
> setup_profiling_timer() is not used by any code at this point. Since a

It is used by write_profile()
https://elixir.bootlin.com/linux/v7.2/source/kernel/profile.c#L202

> default weak implementation exists, there is no need to keep this
> arch-specific definition around. Remove it along with the now-redundant
> profile header includes.
>
> Signed-off-by: Anthony Iliopoulos <ailiop@xxxxxxxx>

> --- a/arch/s390/kernel/smp.c
> +++ b/arch/s390/kernel/smp.c
> @@ -980,17 +980,6 @@ void __init smp_setup_processor_id(void)
>         lc->spinlock_index = 0;
>  }
>
> -/*
> - * the frequency of the profiling timer can be changed
> - * by writing a multiplier value into /proc/profile.
> - *
> - * usually you want to run this on all CPUs ;)
> - */
> -int setup_profiling_timer(unsigned int multiplier)
> -{
> -       return 0;

Just like on SH, this returns zero (success), while the default weak
implementation returns -EINVAL, so your change breaks write_profile().
https://elixir.bootlin.com/linux/v7.2/source/kernel/profile.c#L181

> -}
> -
>  static ssize_t cpu_configure_show(struct device *dev,
>                                   struct device_attribute *attr, char *buf)
>  {

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds