Subject: Re: status of the thorpej_scsipi code
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Charles M. Hannum <root@ihack.net>
List: current-users
Date: 03/29/2001 11:48:32
On Thu, Mar 29, 2001 at 01:23:12PM +0200, Manuel Bouyer wrote:
> On Wed, Mar 28, 2001 at 12:32:42PM -0800, Jason R Thorpe wrote:
> > On Wed, Mar 28, 2001 at 02:26:03PM -0500, Jon Lindgren wrote:
> > 
> >  > This is definitely a dumb question, but can someone give me an outline of
> >  > what this code actually does differently than -current?  Is this a new
> >  > structure of the code, or can we now use target mode on adapters, etc...
> > 
> > Eventually, a generic target mode should be added.
> > 
> > But, mostly, what the thorpej_scsipi code does it provide a bunch of
> > other stuff in the midlayer:
> > 
> > 	- Command queueing and resource management.
> > 
> > 	- Generalized and more flexible support of tagged queueing.
> > 
> > 	- Explicit feature activation (sync, wide, tqing, etc.).
> > 
> > 	- Clean separation of peripherals, channels, and adapters.
> > 
> > 	- Better error recovery.
> > 
> > ...which means that the adapter drivers don't have to manage all that
> > stuff themselves.
> 
> I can add that with this code a i386 GENERIC kernel is slighty smaller:
> text    data    bss     dec     hex     filename
> 4472969 79996   322828  4875793 4a6611  netbsd-thorpej_scsipi
> 4472564 80460   322796  4875820 4a662c  netbsd
> 
> This is because lots of duplicate code have been remomed from drivers (and most
> driver have not been really optimised yet). This also make drivers much
> simpler, so less error-prone.

While that may be an okay overview or abstract, it doesn't tell other
developers jack about the actual API changes.