Re: [PATCH] lockdep: Avoid triggering hardlockup from debug_show_all_locks()

From: Steven Rostedt
Date: Tue Jan 23 2018 - 16:01:01 EST


On Tue, 23 Jan 2018 12:57:06 -0800
Tejun Heo <tj@xxxxxxxxxx> wrote:

> Yeah, it's ridiculous how often printk ends up escalating otherwise
> recoverable situations into system crashes. I don't know what the
> right answer is. For spurious NMI hardlockups, maybe auditing debug
> paths and adding touch_nmi_watchdog() would be enough but that also is
> a pretty leaky approach.

What about if every printk were to touch NMI watchdog?

NMI watchdog is really there for when the system locks up. If the
system is locked up doing printk, at least we see what is happening,
and not a total freeze.

-- Steve