On 07/29/2014 11:22 AM, Christoph Lameter wrote:
> On Tue, 29 Jul 2014, Tejun Heo wrote:
>
>> I'm not sure that's a viable way forward. It's not like we can
>> readily trigger the problematic cases which can lead to long pauses
>> during cpu down. Besides, we need the distinction at the API level,
>> which is the whole point of this. The best way probably is converting
>> all the correctness ones (these are the minorities) over to
>> queue_work_on() so that the per-cpu requirement is explicit.
>
> Ok so we would need this fix to avoid the message:
>
>
> Subject: vmstat: use schedule_delayed_work_on to avoid false positives
>
> It seems that schedule_delayed_work_on will check for preemption even
> though none can occur. schedule_delayed_work_on will not do that. So
> use that function to suppress false positives.
>
> Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
>
> Index: linux/mm/vmstat.c
> ===================================================================
> --- linux.orig/mm/vmstat.c 2014-07-29 10:14:42.356988271 -0500
> +++ linux/mm/vmstat.c 2014-07-29 10:18:28.205920997 -0500
> @@ -1255,7 +1255,8 @@ static void vmstat_update(struct work_st
> * to occur in the future. Keep on running the
> * update worker thread.
> */
> - schedule_delayed_work(this_cpu_ptr(&vmstat_work),
> + schedule_delayed_work_on(smp_processor_id(),
> + this_cpu_ptr(&vmstat_work),
> round_jiffies_relative(sysctl_stat_interval));
> else {
> /*
>
I've tested, and this patch doesn't fix neither of the bugs reported.
Thanks,
Sasha
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>