Re: [PATCH 1/4] sched: Don't account tickless CPU load on tick

[Peter Zijlstra]

On Mon, Feb 01, 2016 at 07:05:13PM +0900, Byungchul Park wrote:
> On Fri, Jan 29, 2016 at 10:50:16AM +0100, Peter Zijlstra wrote:
> > On Thu, Jan 28, 2016 at 05:01:26PM +0100, Frederic Weisbecker wrote:
> > > So lets check all the things we call on scheduler_tick():
> > > 
> > > _ sched_clock_tick(): maybe it doesn't need to be called when idle. I'm not sure.
> > >   Some code in idle (timers, irqs, ...) might need to call sched_clock().
> > 
> > Only needed if you've got a shady TSC.
> 
> Yeh.. IMO, this can be done without the tick handling during nohz, with the
> patch I am attaching. Could you check the patch? Or we have to handle it
> remotely, too. (for a crazy TSC)

I think NOHZ_FULL already requires the TSC not to be wrecked.