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 think NOHZ_FULL_ALL should just die.