Re: [patch 2/2] MM: allow per-cpu vmstat_threshold and vmstat_worker configuration

[Christoph Lameter]

On Fri, 12 May 2017, Marcelo Tosatti wrote:

> > What exactly is the issue you are seeing and want to address? I think we
> > have similar aims and as far as I know the current situation is already
> > good enough for what you may need. You may just not be aware of how to
> > configure this.
>
> I want to disable vmstat worker thread completly from an isolated CPU.
> Because it adds overhead to a latency target, target which
> the lower the better.

NOHZ already does that. I wanted to know what your problem is that you
see. The latency issue has already been solved as far as I can tell .
Please tell me why the existing solutions are not sufficient for you.

> > I doubt that doing inline updates will do much good compared to what we
> > already have and what the dataplan mode can do.
>
> Can the dataplan mode disable vmstat worker thread completly on a given
> CPU?

That already occurs when you call quiet_vmstat() and is used by the NOHZ
logic. Configure that correctly and you should be fine.