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Date: Fri, 7 Nov 2014 13:09:40 -0800 (PST)
From: David Rientjes <rientjes@google.com>
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To: Prarit Bhargava <prarit@redhat.com>
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Subject: Re: [PATCH v8] kernel, add panic_on_warn
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On Fri, 7 Nov 2014, Prarit Bhargava wrote:

> There very much is.  Consider a thread that hits a WARN() and then panics.  Then
> somewhere in the panic code the thread hits another WARN() ... and then panics
> again.  Previously this would have caused the system to "finish" panick'ing.
> Now it makes the system hang.
> 

Then we're back to square one which is what is obviously the intent of 
your patch and the comment that goes along with it: we want to clear 
panic_on_warn once and not allow multiple panic().  So why not just add 
the necessary synchronization to make sure that happens when WARN() 
happens on two cpus simultaneously?