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.
