Re: [RFC/PATCH] posix-timers: make them configurable

From: Thomas Gleixner
Date: Fri Sep 09 2016 - 09:42:03 EST


On Thu, 8 Sep 2016, Nicolas Pitre wrote:
> Small embedded systems typically don't need them. This removes about
> 16KB from the kernel binary size on ARM when configured out.
> Corresponding syscalls are routed to a stub logging the attempt to
> use those syscalls which should be enough of a clue if they were
> disabled without proper consideration.
>
> Signed-off-by: Nicolas Pitre <nico@xxxxxxxxxx>
>
> diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
> index ee3de3421f..00e6098e9a 100644
> --- a/drivers/ptp/Kconfig
> +++ b/drivers/ptp/Kconfig
> @@ -6,7 +6,7 @@ menu "PTP clock support"
>
> config PTP_1588_CLOCK
> tristate "PTP clock support"
> - depends on NET
> + depends on NET && POSIX_TIMERS
> select PPS
> select NET_PTP_CLASSIFY
> help

You forgot CONFIG_TIMERFD ....

> +void do_schedule_next_timer(struct siginfo *info)
> +{
> +}

....

> +void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
> +{
> +}

You should make them static inlines in the headers so they get compiled out
completely.

Thanks,

tglx