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From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [patch 1/6] kmsg: tagged kernel messages.
Date: Mon, 29 Sep 2008 10:35:00 +0200
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Am Sonntag, 28. September 2008 schrieb Rusty Russell:
> On Sunday 28 September 2008 09:16:40 Martin Schwidefsky wrote:
> > On Sat, 2008-09-27 at 17:15 +1000, Rusty Russell wrote:
> > > It's hard for authors (eg. me) to know which level to use.  As a result,
> > > levels currently seem to be chosen randomly.
> > >
> > > If you felt inspired to rationalize them, it would let us clean that up
> > > as things moved to kmsg :)
> >
> > Urgs, you are after a sort of definition what the differences is between
> > a warning, an error, an alert, etc is, aren't you?
> 

Rusty,

Since Kernel message levels are used directly by syslog, the Open Group Base 
Specifications Issue 6 defines what these levels are:
http://www.opengroup.org/onlinepubs/009695399/basedefs/syslog.h.html

LOG_EMERG
A panic condition was reported to all processes.
LOG_ALERT
A condition that should be corrected immediately.
LOG_CRIT
A critical condition.
LOG_ERR
An error message.
LOG_WARNING
A warning message.
LOG_NOTICE
A condition requiring special handling.
LOG_INFO
A general information message.
LOG_DEBUG
A message useful for debugging programs.

I dont think, that the kernel should define anything different.
We could add a more verbose description or a howto to CodingStyle later on, 
but this is really orthogonal to kmsg and would be valid for printk, 
dev_printk and any other printk wrapper.

Futhermore, this really smells like a bike shed color question and IMHO we 
should not hold of the kmsg patches to answer this kind of controversial 
questions ;-)

Christian