On Thu, Oct 16, 2014 at 06:48:15PM +0900, Yasuaki Ishimatsu wrote:
> +++ b/kernel/sched/fair.c
> @@ -1466,6 +1466,7 @@ static void update_task_scan_period(struct task_struct
> *p,
>
> unsigned long remote = p->numa_faults_locality[0];
> unsigned long local = p->numa_faults_locality[1];
> + unsigned long total_faults = shared + private;
>
> /*
> * If there were no record hinting faults then either the task is
> @@ -1496,6 +1497,14 @@ static void update_task_scan_period(struct task_struct
> *p,
> slot = 1;
> diff = slot * period_slot;
> } else {
> + /*
> + * This is a rare case. total_faults might become 0 after
> + * offlining node. In this case, total_faults is set to 1
> + * for avoiding divide error.
> + */
> + if (unlikely(total_faults == 0))
> + total_faults = 1;
> +
> diff = -(NUMA_PERIOD_THRESHOLD - ratio) * period_slot;
>
> /*
> @@ -1506,7 +1515,7 @@ static void update_task_scan_period(struct task_struct
> *p,
> * scanning faster if shared accesses dominate as it may
> * simply bounce migrations uselessly
> */
> - ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private +
> shared));
> + ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS,
> (total_faults));
> diff = (diff * ratio) / NUMA_PERIOD_SLOTS;
So what was wrong with the 'normal' unconditional +1 approach? Also
you've got superfluous parenthese.
--
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/
