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? Thanks Vivek