Re: [PATCH tip/core/rcu 11/17] rcu: Bind grace-period kthreads to non-NO_HZ_FULL CPUs

From: Christoph Lameter
Date: Fri Jul 11 2014 - 15:05:20 EST

On Fri, 11 Jul 2014, Frederic Weisbecker wrote:

> > That would imply that all no-nohz processors are housekeeping? So all
> > processors with a tick are housekeeping?
> Well, now that I think about it again, I would really like to keep housekeeping
> to CPU 0 when nohz_full= is passed.


> > Could we make that set configurable? Ideally I'd like to have the ability
> > restrict the housekeeping to one processor.
> Ah, I'm curious about your usecase. But I think we can do that. And we should.

The use case is pretty straightforward because we are trying to keep as
much OS noise as possible off most processors. Processor 0 is the
sacrificial lamb that will be used for all OS processing and hopefully all
high latency operations will occur there. Processors 1-X have a tick but
we still try to keep latencies sane. And then there is X-Y where tick is
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