Re: [PATCH 2/2] nohz: make nohz_full imply isolcpus

[Chris Metcalf]

On 04/03/2015 02:08 PM, Mike Galbraith wrote:
> On Fri, 2015-04-03 at 12:24 -0400, cmetcalf@xxxxxxxxxx wrote:
> > From: Chris Metcalf <cmetcalf@xxxxxxxxxx>
> >
> > It's not clear that nohz_full is useful without isolcpus also
> > set, since otherwise the scheduler has to run periodically to
> > try to determine whether to steal work from other cores.
> >
> > Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
> Ack!  nohz_full= as currently defined makes zero sense when the cpu
> set (which should be spelled cpuset) remains connected to the
> scheduler.  Perturbation of tasks to PREVENT cpu domination is what
> the scheduler does for a living.  Sprinkling microsecond savers all
> over the kernel is pretty silly if you don't shut down the mother lode
> of perturbation.

Sounds like a thumbs up for this patch, then?  :-)

--
Chris Metcalf, EZChip Semiconductor
http://www.ezchip.com

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