Re: [PATCH v2 1/2] Replace if statement with WARN_ON_ONCE() in cmci_rediscover().

From: Tang Chen
Date: Mon Oct 22 2012 - 21:36:14 EST

On 10/22/2012 06:14 PM, Borislav Petkov wrote:
On Mon, Oct 22, 2012 at 10:10:24AM +0800, Tang Chen wrote:
I don't why before we just jumped over it. But I think if we have an
online cpu == dying here, it must be wrong. So I think we should warn
it, not just jump over it.

Why do we need to warn? What good would that bring us?

AFAICT, the check in cmci_rediscover is there to make sure we absolutely
don't rediscover on the dying cpu. I think it is a safety precaution in
concurrency scenarios between cpu hotplug and mce code.

Hi Borislav,

As I said, cmci_rediscover() is only used to handle CPU_POST_DEAD event.
And is uses for_each_online_cpu to iterate all online cpus. If we get a
online cpu == dying, I think we are in a wrong situation. I think at
least, we should give a warning.

Thanks. :)


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