On 03/26/2014 04:51 PM, Viresh Kumar wrote:
> In switch_hrtimer_base() we have created a local variable basenum which is set
> to base->index. This variable is used at only one place. It makes code more
> readable if we remove this variable use base->index directly.
>
No, this doesn't look right. Note that the code can re-execute
the assignment to new_base, by jumping to the 'again' label.
See below.
> --- a/kernel/hrtimer.c
> +++ b/kernel/hrtimer.c
> @@ -202,11 +202,10 @@ switch_hrtimer_base(struct hrtimer *timer, struct
> hrtimer_clock_base *base,
> struct hrtimer_cpu_base *new_cpu_base;
> int this_cpu = smp_processor_id();
> int cpu = get_nohz_timer_target(pinned);
> - int basenum = base->index;
>
> again:
> new_cpu_base = &per_cpu(hrtimer_bases, cpu);
> - new_base = &new_cpu_base->clock_base[basenum];
> + new_base = &new_cpu_base->clock_base[base->index];
>
Further down, timer->base can be altered (and set to NULL too).
So if we jump back to 'again', we'll end up in trouble.
So I think its important to cache the value in basenum and
use it.
> if (base != new_base) {
> /*
>
Regards,
Srivatsa S. Bhat
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