Messages in this thread | | | Date | Fri, 7 Nov 2014 02:15:46 -0800 (PST) | From | David Rientjes <> | Subject | Re: [PATCH v8] kernel, add panic_on_warn |
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On Thu, 6 Nov 2014, 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? >
No issue at all, what's completely mysterious is the panic_on_warn = 0 and the completely bogus comment that says "prevent further WARN()s from panicking the system" when that's racy. There's no need to clear panic_on_warn at all.
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