Re: [RFC PATCH v2 4/8] tick/nohz: keep tick on for a fast idle

From: Li, Aubrey
Date: Mon Oct 16 2017 - 01:35:14 EST


On 2017/10/16 12:45, Mike Galbraith wrote:
> On Mon, 2017-10-16 at 11:26 +0800, Li, Aubrey wrote:
>>
>> I'll try to move quiet_vmstat() into the normal idle branch if this patch series
>> are reasonable. Is fast_idle a good indication for it?
>
> see x86_tip 62cb1188ed86 sched/idle: Move quiet_vmstate() into the NOHZ code

It looks like this commit makes tick stop critical as it can be invoked in interrupt
exit path?

->smp_apic_timer_interrupt
-->irq_exit
--->tick_nohz_irq_exit
---->__tick_nohz_idle_enter
----->tick_nohz_stop_sched_tick
------>quiet_vmstat

Thanks,
-Aubrey