Re: [PATCH v4] panic: Avoid the extra noise dmesg

From: Steven Rostedt
Date: Mon Dec 10 2018 - 13:17:35 EST

On Fri, 7 Dec 2018 17:51:19 +0800
Feng Tang <feng.tang@xxxxxxxxx> wrote:

> When kernel panic happens, it will first print the panic call stack,
> then the ending msg like:
> [ 35.743249] ---[ end Kernel panic - not syncing: Fatal exception
> [ 35.749975] ------------[ cut here ]------------
> The above message are very useful for debugging.
> But if system is configured to not reboot on panic, say the "panic_timeout"
> parameter equals 0, it will likely print out many noisy message like
> WARN() call stack for each and every CPU except the panic one, messages
> like below:

> Keeping the interrupt disabled will avoid the noisy message.
> When code runs to this point, it means user has chosed to not reboot, or
> do any special handling by using the panic notifier method, the only reason
> to enable the interrupt may be sysrq migic key and panic_blink function
> (though may not work even with irq enabled).
> So make the irq disabled by default and add a cmdline parameter
> "panic_keep_irq_on" to turn it on when needed.
> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>

Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

-- Steve