Re: [RFC PATCH 2/5] sched: Add NOHZ_STATS_KICK

[Peter Zijlstra]

On Fri, Dec 22, 2017 at 09:05:45AM +0100, Vincent Guittot wrote:
> On 22 December 2017 at 08:59, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > On Thu, Dec 21, 2017 at 05:56:32PM +0100, Vincent Guittot wrote:
> >> In fact, we can't only rely on the tick and newly_idle load balance to
> >> ensure a period update of the blocked load because they can never
> >> happen.
> >
> > I'm confused, why would the ilb not happen?
> 
> the ilb will be kick only if tick fires which might not be the case
> for task that runs less than a tick

Oh, urgh, you're talking about when the entire system is idle. Yes
indeed.

Lemme have a think, surely we can do something saner there.