On 09/26/2012 03:16 PM, Wolfgang Mauerer wrote:
> Make the control flow more readable. No functional changes.
>
> Signed-off-by: Wolfgang Mauerer <wolfgang.maue...@siemens.com>
> ---
> kernel/ipipe/timer.c | 82 +++++++++++++++++++++++++++++++------------------
> 1 files changed, 52 insertions(+), 30 deletions(-)
>
> diff --git a/kernel/ipipe/timer.c b/kernel/ipipe/timer.c
> index 8b2eb6f..765340e 100644
> --- a/kernel/ipipe/timer.c
> +++ b/kernel/ipipe/timer.c
> @@ -154,21 +154,55 @@ static void ipipe_timer_request_sync(void)
> timer->request(timer, steal);
> }
>
> +/* Set up a timer as per-cpu timer for ipipe */
> +static int install_pcpu_timer(unsigned cpu, unsigned hrclock_freq,
> + struct ipipe_timer *t) {
> + unsigned hrtimer_freq;
> + unsigned long long tmp;
> +
> +#ifdef CONFIG_GENERIC_CLOCKEVENTS
> + struct clock_event_device *evtdev;
> + evtdev = t->host_timer;
> +
> + if (evtdev && evtdev->mode == CLOCK_EVT_MODE_SHUTDOWN)
> + return 0;
> +#endif /* CONFIG_GENERIC_CLOCKEVENTS */
> +
> + if (__ipipe_hrtimer_freq == 0)
> + __ipipe_hrtimer_freq = t->freq;
> +
> + per_cpu(ipipe_percpu.hrtimer_irq, cpu) = t->irq;
> + per_cpu(percpu_timer, cpu) = t;
> +
> + hrtimer_freq = t->freq;
> + if (__ipipe_hrclock_freq > UINT_MAX)
> + hrtimer_freq /= 1000;
> +
> + t->c2t_integ = hrtimer_freq / hrclock_freq;
> + tmp = (((unsigned long long)
> + (hrtimer_freq % hrclock_freq)) << 32)
> + + hrclock_freq - 1;
> + do_div(tmp, hrclock_freq);
> + t->c2t_frac = tmp;
> +
> + return 1;
> +}
> +
> +
> /*
> - * choose per-cpu timer: we walk the list, and find the timer with the
> - * highest rating.
> + * Choose per-cpu timers with the highest rating by traversing the
> + * rating-sorted list for each CPU.
> */
> int ipipe_select_timers(const struct cpumask *mask)
> {
> - struct clock_event_device *evtdev;
> - unsigned hrclock_freq, hrtimer_freq;
> + unsigned hrclock_freq;
> unsigned long long tmp;
> struct ipipe_timer *t;
> unsigned long flags;
> - unsigned cpu, khz;
> + unsigned cpu;
> + bool found;
>
> - khz = __ipipe_hrclock_freq > UINT_MAX;
> - if (khz) {
> + if (__ipipe_hrclock_freq > UINT_MAX) {
> tmp = __ipipe_hrclock_freq;
> do_div(tmp, 1000);
> hrclock_freq = tmp;
> @@ -177,34 +211,22 @@ int ipipe_select_timers(const struct cpumask *mask)
>
> spin_lock_irqsave(&lock, flags);
> for_each_cpu(cpu, mask) {
> + found = false;
> list_for_each_entry(t, &timers, link) {
> if (!cpumask_test_cpu(cpu, t->cpumask))
> continue;
>
> - evtdev = t->host_timer;
> -#ifdef CONFIG_GENERIC_CLOCKEVENTS
> - if (!evtdev
> - || evtdev->mode != CLOCK_EVT_MODE_SHUTDOWN)
> -#endif /* CONFIG_GENERIC_CLOCKEVENTS */
> - goto found;
> + if (install_pcpu_timer(cpu, hrclock_freq, t)) {
> + found = true;
Talking about readability, I find a goto with a clear label name much
more readable than a flag. So, NACK this patch, please keep the goto.
--
Gilles.
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