Re: PATCH: Fix race in cpu_down (hotplug cpu)

Nick Piggin
2005-09-19T07:22:34Z

On Mon, 2005-09-19 at 15:12 +0800, Shaohua Li wrote:
> On Mon, 2005-09-19 at 16:36 +1000, Nick Piggin wrote:

> > Ah, actually I have a patch which makes all CPU idle threads
> > run with preempt disabled and only enable preempt when scheduling.
> > Would that help?
> It should solve the issue to me. Should we take care of the latency?
> acpi_processor_idle might execute for a long time.
>

Oh really? I think yes, the latency should be taken care of because
we want to be able to provide good latency even for !preempt kernels.
If a solution can be found for acpi_processor_idle, that would be
ideal.

IMO it always felt kind of hackish to run the idle threads with
preempt on.

Thanks,
Nick

--
SUSE Labs, Novell Inc.

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