Zhiqiang,
On Mon, 24 Jun 2019, Zhiqiang Liu wrote:
> 在 2019/6/24 0:38, Thomas Gleixner 写道:
> > If we keep it jiffies based, then microseconds do not make any sense. They
> > just give a false sense of controlability.
> >
> > Keep also in mind that with jiffies the accuracy depends also on the
> > distance to the next tick when 'end' is evaluated. The next tick might be
> > imminent.
> >
> > That's all information which needs to be in the documentation.
> >
>
> Thanks again for your detailed advice.
> As your said, the max_softirq_time_usecs setting without explaining the
> relationship with CONFIG_HZ will give a false sense of controlability. And
> the time accuracy of jiffies will result in a certain difference between the
> max_softirq_time_usecs set value and the actual value, which is in one jiffies
> range.
>
> I will add these infomation in the sysctl documentation and changelog in v2
> patch.
Please make the sysctl milliseconds based. That's the closest approximation
of useful units for this. This still has the same issues as explained
before but it's not off by 3 orders of magitude anymore.
Thanks,
tglx
