Re: [PATCH] irq_work: unhide irq_work_queue_on declaration on non-SMP

[Rafael J. Wysocki]

On Wed, Feb 10, 2016 at 4:07 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> The cpufreq code uses 'if (IS_ENABLED(CONFIG_SMP))' to check
> whether it should queue a task on the local CPU or a remote
> one, however the irq_work_queue_on() function is not declared
> when CONFIG_SMP is not set:
>
> drivers/cpufreq/cpufreq_governor.c: In function 'gov_queue_irq_work':
> drivers/cpufreq/cpufreq_governor.c:251:3: error: implicit declaration of function 'irq_work_queue_on' [-Werror=implicit-function-declaration]
>    irq_work_queue_on(&policy_dbs->irq_work, smp_processor_id());
>
> This changes the conditional declaration so that irq_work_queue_on
> just queues the irq work on the only available CPU when CONFIG_SMP
> is not set, which is presumably what most people need anyway.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Fixes: 0144fa03ef46 ("cpufreq: governor: Replace timers with utilization update callbacks")
>
> diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
> index 47b9ebd4a74f..c9bde50ef317 100644
> --- a/include/linux/irq_work.h
> +++ b/include/linux/irq_work.h
> @@ -33,9 +33,13 @@ void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))
>  #define DEFINE_IRQ_WORK(name, _f) struct irq_work name = { .func = (_f), }
>
>  bool irq_work_queue(struct irq_work *work);
> -
>  #ifdef CONFIG_SMP
>  bool irq_work_queue_on(struct irq_work *work, int cpu);
> +#else
> +static inline bool irq_work_queue_on(struct irq_work *work, int cpu)
> +{
> +       return irq_work_queue(work);
> +}
>  #endif
>
>  void irq_work_tick(void);

I was thinking about this too, but then cpufreq will be the only user of it.

In any case can do it at any time later. :-)

Thanks,
Rafael