Re: [RFC PATCH v3 1/9] CPU hotplug: Provide APIs to prevent CPUoffline from atomic context

From: Oleg Nesterov
Date: Sun Dec 09 2012 - 16:13:27 EST


Damn, sorry for noise. I missed this part...

On 12/10, Srivatsa S. Bhat wrote:
>
> On 12/10/2012 12:44 AM, Oleg Nesterov wrote:
> > the latency. And I guess something like kick_all_cpus_sync() is "too heavy".
>
> I hadn't considered that. Thinking of it, I don't think it would help us..
> It won't get rid of the currently running preempt_disable() sections no?

Sure. But (again, this is only my feeling so far) given that get_online_cpus_atomic()
does cli/sti, this can help to implement ensure-the-readers-must-see-the-pending-writer.
IOW this might help to implement sync-with-readers.

Oleg.

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