Re: [PATCH v2] sched/rt: hide push_irq_work_func declaration

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 12 Nov 2015 17:19:58 +0100
Arnd Bergmann <arnd@arndb.de> wrote:

> The push_irq_work_func() function is conditionally defined only
> when both CONFIG_SMP and HAVE_RT_PUSH_IPI are defined, but the
> forward declaration remains visibile without HAVE_RT_PUSH_IPI,
> causing a gcc warning in ARM64 allnoconfig:
> 
> kernel/sched/rt.c:68:13: warning: 'push_irq_work_func' declared 'static' but never defined [-Wunused-function]
> 
> This changes the code to use the same condition for both the
> declaration and the function definition, which gets rid of the
> warning.
> 
> As Peter Zijlstra, we can possibly get rid of the whole HAVE_RT_PUSH_IPI
> thing after:
> 8053871d0f7f ("smp: Fix smp_call_function_single_async() locking")
> 
> Until that is done, this patch can be used to avoid the warning.

Acked-by: Steven Rostedt <rostedt@goodmis.org>

-- Steve

> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: b6366f048e0c ("sched/rt: Use IPI to trigger RT task push migration instead of pulling")
> ---
> Found on arm64 allnoconfig
> 
> v2: now using #if defined() instead IS_ENABLED()
> 
> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
> index e3cc16312046..ce7b36d6f477 100644
> --- a/kernel/sched/rt.c
> +++ b/kernel/sched/rt.c
> @@ -64,7 +64,7 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
>         raw_spin_unlock(&rt_b->rt_runtime_lock);
>  }
>  
> -#ifdef CONFIG_SMP
> +#if defined(CONFIG_SMP) && defined(HAVE_RT_PUSH_IPI)
>  static void push_irq_work_func(struct irq_work *work);
>  #endif
>