linux-kernel - Re: [PATCH] MAINTAINERS: Add printk maintainers

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Message-ID: <20161215122027.0f18bfb1@gandalf.local.home>
Date:   Thu, 15 Dec 2016 12:20:27 -0500
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Petr Mladek <pmladek@...e.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] MAINTAINERS: Add printk maintainers

On Thu, 15 Dec 2016 18:12:00 +0100
Peter Zijlstra <peterz@...radead.org> wrote:

> On Thu, Dec 15, 2016 at 03:34:43PM +0100, Petr Mladek wrote:
> > We have to find the right balance. For example, we do not show
> > messages immediately in NMI context because there is a risk
> > of a deadlock.  
> 
> I find the occasional deadlock much preferable to guaranteed no output.

Right, we can't stress the importance of getting output out when it
happens. A printk dump is the first course of action when debugging a
crash. And the printk output shows how much progress the computer made.

If all printks are asynchronous, that will be unreliable information.
And really, that information can be extremely useful, but only if it is
reliable, otherwise, it becomes useless.

-- Steve