Re: [PATCH 12/32] nohz: Try not to give the timekeeping duty to a cpuset nohz cpu

Frederic Weisbecker
2011-08-30T15:17:14Z

On Mon, Aug 29, 2011 at 04:55:45PM +0200, Peter Zijlstra wrote:
> On Mon, 2011-08-15 at 17:52 +0200, Frederic Weisbecker wrote:
> > Try to give the timekeeing duty to a CPU that doesn't belong
> > to any nohz cpuset when possible, so that we increase the chance
> > for these nohz cpusets to run their CPUs out of periodic tick
> > mode.
>
> You and Dmitiri might want to get together:
>
> lkml.kernel.org/r/20110823195628.GB4533@sgi.com

Right!

There is another missing piece in my patchset. If every non adaptive-nohz
CPUs are sleeping, then none is handling the do_timer duty and adaptive nohz
CPUs run with a stale jiffies and walltime.

I need to handle that.