Subject: Re: FreeBSD Bus DMA
To: John S. Dyson <dyson@freebsd.org>
From: Hank <hank@black-hole.com>
List: tech-kern
Date: 06/11/1998 19:37:08
On Thu, 11 Jun 1998, John S. Dyson wrote:

>Perry E. Metzger said:
<snip about flying off the handle>
>
>> 
>> HOWEVER, my point still stands. I believe claims of improved
>> performance when I see reproduceable benchmarks. I believe claims of
>> portability when I see a port. I *know* that NetBSD's code ports well, 
>> because we spent years beating on it until it would. FreeBSD hasn't
>> finished one port from its original architecture. I would like to see
>> justification for claims of performance and portability -- not
>> theoreticals.
>> 
>Does that mean that the FreeBSD development should move forward,
>and then when we  have reproduceable benchmarks on FreeBSD, then
>you can choose to adopt our code, or leave it be?

Not nessiacrly.  NetBSD and FreeBSD have different goals.  FreeBSD strives
to be the best for x86 platforms.  NetBSD strives to be good on every
possibal platform.  Although we would like to be best on all of them
reality hits, and once in a while we choose to be "less" in some way on
some platform so that we are portable to everything.  This is what
everyone was saying in the flame fest that we have all seen.  Different
goal, so we do have to be different.  

Where possibal NetBSD would like to take work that you folks in FreeBSD
have done, to make ourselves better (and we welcome you to do the same)
BUT we cannot take work you have done if that work will not port easially
to everything.  (including computers that do not exist yet, at least as
far as possibal)

The upshot is while there are gains to be made in having common structures
between our two platforms, sometimes our differeng goals will force us
apart. Even if you come up with benchmarks on every x86 platform ever (an
inhuman task) proving that your way is the fastest on x86, we may choose
not to use your work if it doesn't work so well on other platforms.  This
is not bad for either of us, just different.

Remember that FreeBSD still only supports one architecture.  While it has
undergone some revisions over the years, there are some BIG portibility
problems that we will uncover that won't effect FreeBSD.  Do not let
NetBSD's goals prevent you from moving forward.  Do not let a desire to
move forward distract you from the issues NetBSD discovers - they may hit
you in next years model.

--
      http://blugill.home.ml.org/    
      hank@black-hole.com