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

Nick Piggin
2005-09-19T06:36:48Z

On Mon, 2005-09-19 at 14:37 +0800, Shaohua Li wrote:
> On Mon, 2005-09-19 at 11:53 +0530, Srivatsa Vaddagiri wrote:

> > default_idle should be fine as it is. IOW it should not cause __cpu_die to
> > timeout.
> Why default_idle should be fine? it can be preempted before the
> 'local_irq_disable' check. Even with Nigel's patch, there is a very
> small window at safe_halt (after 'sti' but before 'hlt').
>

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?

Nick

--
SUSE Labs, Novell Inc.

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