Re: [PATCH v5 8/8] sched/numa: drop unnecessary variable intask_weight

[Naoya Horiguchi]

On Wed, Dec 11, 2013 at 09:21:23AM +0000, Mel Gorman wrote:
> On Wed, Dec 11, 2013 at 08:50:01AM +0800, Wanpeng Li wrote:
> > Drop unnecessary total_faults variable in function task_weight to unify
> > task_weight and group_weight.
> > 
> > Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> > Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
> 
> Nak.
> 
> task_weight is called for tasks other than current. If p handles a fault
> in parallel then it can drop to 0 between when it's checked and used to
> divide resulting in an oops.

So we have the same race on group_weight(), and we have to add a local
variable to store p->numa_group->total_faults?

Thanks,
Naoya Horiguchi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/