Subject: Re: status of the thorpej_scsipi code
To: Jason R Thorpe , Jon Lindgren <firstname.lastname@example.org>
From: Manuel Bouyer <email@example.com>
Date: 03/29/2001 13:23:12
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.
Manuel Bouyer, LIP6, Universite Paris VI. Manuel.Bouyer@lip6.fr