Re: [RFC PATCH 0/9] Introduce housekeeping subsystem

From: Mike Galbraith
Date: Fri Aug 11 2017 - 02:37:26 EST


On Thu, 2017-08-10 at 09:57 -0400, Chris Metcalf wrote:
> On 8/10/2017 8:54 AM, Frederic Weisbecker wrote:
> > But perhaps I should add a new NO_HZ_FULL_BUT_HOUSEKEEPING option.
> > Otherwise we'll change the meaning of NO_HZ_FULL_ALL way too much, to the point
> > that its default behaviour will be the exact opposite of the current one: by default
> > every CPU is housekeeping, so NO_HZ_FULL_ALL would have no effect anymore if we
> > don't set housekeeping boot option.
>
> Maybe a CONFIG_HOUSEKEEPING_BOOT_ONLY as a way to restrict housekeeping
> by default to just the boot cpu. In conjunction with NOHZ_FULL_ALL you would
> then get the expected semantics.

A big box with only the boot cpu for housekeeping is likely screwed.

Personally, I thinkÂNOHZ_FULL_ALL should just die.

-Mike