[PATCH v8] kernel, add panic_on_warn

Prarit Bhargava prarit at redhat.com
Thu Nov 6 14:52:05 PST 2014



On 11/06/2014 05:07 PM, Vivek Goyal wrote:
> On Thu, Nov 06, 2014 at 01:57:36PM -0800, David Rientjes wrote:
> 
> [..]
>> You see that doing
>>
>> 	if (panic_on_warn) {
>> 		panic_on_warn = 0;
>> 		panic(...);
>> 	}
>>
>> is racy, I hope.  If two threads WARN() at the same time, then there's 
>> nothing preventing a double panic() because WARN() itself is not 
>> serialized against anything.  So both the current comment and your 
>> suggested revision comment are bogus.
> 
> panic() is serialized on panic_lock. So I guess it is fine to hit WARN()
> on multiple cpus. Do you see an issue there?

Oops -- didn't see this until just now.

Once again, Vivek beat me to the punch :) and much more succinctly than I will
ever be able to do. :)

P.

> 
> Thanks
> Vivek
> 



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