Re: [PATCH 3/3] lockdep: Use line-buffered printk() for lockdep messages.

From: Steven Rostedt
Date: Fri Nov 23 2018 - 10:56:40 EST


On Fri, 23 Nov 2018 13:46:47 +0100
Petr Mladek <pmladek@xxxxxxxx> wrote:

> Steven told me on Plumbers conference that even few initial
> characters saved him a day few times.

Yes, and that has happened more than once. I would reboot and retest
code that is crashing, and due to a triple fault, the machine would
reboot because of some race, and the little output I get from the
console would help tremendously.

Remember, debugging the kernel is a lot like forensics, especially when
it's from a customer's site. You look at all the evidence that you can
get, and sometimes it's just 10 characters in the output that gives you
an idea of where things went wrong. I'm really not liking the buffering
idea because of this.

-- Steve