Subject: Re: status of the thorpej_scsipi code
To: Manuel Bouyer <email@example.com>
From: Charles M. Hannum <firstname.lastname@example.org>
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.