# Re: clocksource\_watchdog causing scheduling of timers every second (was \[v13\] support "task\_isolation" mode)

- From: Christoph Lameter \<hidden\>
- Date: 2016-08-11 23:02:39 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2016/08/4812700
- Thread: https://ratatoskr.run/linux-api/2016/07/4795325/t.md

```text
On Thu, 11 Aug 2016, Paul E. McKenney wrote:

> > With modern Intel we could run it on one CPU per package I think, but at
> > the same time, too much in NOHZ_FULL assumes the TSC is indeed sane so
> > it doesn't make sense to me to keep the watchdog running, when it
> > triggers it would also have to kill all NOHZ_FULL stuff, which would
> > probably bring the entire machine down..
>
> Well, you -could- force a very low priority CPU-bound task to run on
> all nohz_full CPUs.  Not necessarily a good idea, but a relatively
> non-intrusive response to that particular error condition.

Given that we want the cpu only to run the user task I would think that is
not a good idea.
```