On 03/26/2014 04:51 PM, Viresh Kumar wrote:
> In hrtimers_init() we need to call init_hrtimers_cpu() for boot CPU. For this,
> currently we are emulating a call to hotplug notifier. Probably this was done
> initially to get rid of code redundancy. But this sequence always called a
> single routine, i.e. init_hrtimers_cpu(), and so calling that routine directly
> would be better. This would get rid of emulating a notifier call, few
> typecasts
> and the extra steps we are doing in notifier callback.
>
> So, this patch calls init_hrtimers_cpu() directly from hrtimers_init().
>
I don't think this is such a good idea. Open-coding a part of that callback
in the init routine can lead to loop-holes down the road: what if someone
changes or adds something to the CPU_UP_PREPARE switch-case, and forgets to
do the same in the init-routine?
It is more comforting to know that there is just one single place where CPU
hotplug operations are handled (hrtimer_cpu_notify). That, in turn is good
for reliability because it makes it easier to write bug-free code.
Regards,
Srivatsa S. Bhat
> Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
> ---
> kernel/hrtimer.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
> index f14d861..39dbdbd 100644
> --- a/kernel/hrtimer.c
> +++ b/kernel/hrtimer.c
> @@ -1756,8 +1756,7 @@ static struct notifier_block hrtimers_nb = {
>
> void __init hrtimers_init(void)
> {
> - hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
> - (void *)(long)smp_processor_id());
> + init_hrtimers_cpu(smp_processor_id());
> register_cpu_notifier(&hrtimers_nb);
> #ifdef CONFIG_HIGH_RES_TIMERS
> open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
