Re: [RFC/PATCH] Documentation of kernel messages

[holzheu <holzheu@linux.vnet.ibm.com>]

Hi Pavel,

On Fri, 2007-06-15 at 12:40 +0000, Pavel Machek wrote:
> Hi!
> 
> > > Your proposal is similar to one I made to some Japanese developers
> > > earlier this year.  I was more modest, proposing that we
> > > 
> > > - add an enhanced printk
> > > 
> > > 	xxprintk(msgid, KERN_ERR "some text %d\n", some_number);
> >   Maybe a stupid idea but why do we want to assign these numbers by hand?
> > I can imagine it could introduce collisions when merging tons of patches
> > with new messages... Wouldn't it be better to compute say, 8-byte hash
> > from the message and use it as it's identifier? We could do this
> 
> Why hashes? Just key it off full message, and treat it like normal
> translation problem.
> 
> 'lp%d: on fire' -> 'your printer failed basic tests, you should check
> cabling'.

Hmmm... What about extracting all format strings from the KMSG_DOC
macros and storing them in a file. E.g.:

  printk("lp%d: on fire");

  /**
   * message
   *
   * Description:
   * Your printer failed basic tests, you should check cabling
   ...

  KMSG_DOC(lp, "lp%d: on fire");

Some build mechanism creates a file with all format strings of the
KMSG_DOC macros:

E.g.: cat kmsgs.txt

# MSG:       "lp%d: on fire"
# COMPONENT: lp
# DESC:      Your printer failed basic tests, you should check cabling

Then we provide a tool e.g. "kmsg", which gets as input the actual
kernel message and searches the message database for matching format
strings:

>> kmsg "lp0: on fire"
>> Your printer ...

Of course, we can get duplicate hits, too.

The advantage of that approach is, that we don't need additional message
identifiers like hashes.

Michael