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.kumar@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);