Re: [RFC PATCH 4/4] sched: Upload nohz full CPU load on task enqueue/dequeue

From: Frederic Weisbecker
Date: Wed Jan 20 2016 - 11:47:35 EST

On Wed, Jan 20, 2016 at 10:42:56AM -0600, Christoph Lameter wrote:
> On Wed, 20 Jan 2016, Frederic Weisbecker wrote:
> > > So we agreed long time ago, that we first fix the issues with s single task
> > > running undisturbed in user space, i.e. tickless. Those issues have never been
> > > resolved fully, but now you try to add more complexity of extra runnable
> > > tasks, nohz tasks sleeping and whatever.
> >
> > Nohz tasks do sleep, really, at least we need to handle that case now.
> Sleep meaning call into the OS to be put to sleep?

Indeed, when the task has finished its work, it goes to sleep, right?

> Why would NOHZ be active then?

It's active when the task active.