Subject: Re: [patch 1/3] kmsg: Kernel message catalog macros.
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reply-To: schwidefsky@de.ibm.com
To: Greg KH <gregkh@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>, linux-kernel@vger.kernel.org,
       linux-s390@vger.kernel.org,
       lf_kernel_messages@lists.linux-foundation.org,
       Andrew Morton <akpm@linux-foundation.org>,
       Michael Holzheu <holzheu@de.ibm.com>, Gerrit Huizenga <gh@us.ibm.com>,
       Randy Dunlap <randy.dunlap@oracle.com>, Jan Kara <jack@suse.cz>,
       Pavel Machek <pavel@ucw.cz>, Sam Ravnborg <sam@ravnborg.org>,
       Joe Perches <joe@perches.com>,
       Jochen =?ISO-8859-1?Q?Vo=DF?= <jochen.voss@googlemail.com>,
       Kunai Takashi <kunai@linux-foundation.jp>,
       Tim Bird <tim.bird@am.sony.com>
In-Reply-To: <20080806200721.GA30086@suse.de>
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Organization: IBM Corporation
Date: Thu, 07 Aug 2008 10:31:41 +0200
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On Wed, 2008-08-06 at 13:07 -0700, Greg KH wrote:
> > > > Using dev_printk won't work because of the order of the elements of the
> > > > printk. The kmsg tag should not have a "random" position in the printk
> > > > but should be the first element. If we use dev_printk the kmsg tag will
> > > > be the third element, for other kmsg printks it will be the first. In
> > > > addition the kmsg message tag for the device drivers already includes
> > > > the driver name ..
> > > 
> > > But the structure of dev_printk() is well definied and should be pretty
> > > trival to parse even with missing fields.
> > 
> > The missing field is the message tag. Which is the key for the message
> > lookup. As far as the kmsg catalog is concerned this is a pretty
> > important field that may not be missing from the printk itself.
> 
> No, I mean use dev_printk() as the base for your logging macro.  Add
> your message tag as the first field after the dev_printk() information.

Hmm, you are proposing to introduce a second format for the kmsg
messages to avoid the need for some more printk wrapper macros. To me it
seems that this has two problems:
1) The message tag is for the user of the system. If it does not have a
fixed position it gets confusing.
2) The message tag for a driver message usually already includes the
driver name, the dev_printk will print it again. This is ugly and
reduces the quality of the message.

-- 
blue skies,
  Martin.

"Reality continues to ruin my life." - Calvin.


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