Subject: Re: FreeBSD Bus DMA
To: None <>
From: John S. Dyson <>
List: tech-kern
Date: 06/11/1998 20:15:19
Perry E. Metzger said:
> "John S. Dyson" writes:
> > Funny, that is why our build times are 3X faster on FreeBSD, for NetBSD
> > based products than on NetBSD, right?  We even have a development
> > team avoiding *BSD all together because of NetBSD/X86 performance
> > problems.
> Huh?
> You are claiming that FreeBSD is three times faster than NetBSD on
> identical hardware? THREE TIMES?
> My last check determined that, so far as I could tell, NetBSD and
> FreeBSD were more or less within a few percent of each other in
> performance. NetBSD is faster at some things, slower at others --
> certainly no real measurable difference.
How are you measuring it?  Probably with unloaded system or LL benchmarks.
Gessh, in a spin-loop NT is as fast as FreeBSD, right?

> If you feel there is a difference, though, feel free to present a
> benchmark.
Just do a massive compile, with FreeBSD set up correctly...  You
can do it.  It is pretty obvious if you actually try it.  Our people
are happy about the change in compile times (it is massive.)

> "Huh?"
> Please, feel free to show us the numbers.
Experience by others trying to get software built.  In fact, it
was NetBSD :-).

> Might I ask, btw, why the "FreeBSD" Alpha folks are using a NetBSD
> kernel?
Not for long.   Purely a bootstrapping issue.  Did the NetBSD people
ever use SunOS or Solaris?  BTW, wich do you othink works better?
SunOS or NetBSD?  I kind of like the progression: OSF/1->NetBSD->FreeBSD.

> > FreeBSD isn't perfect, but also claiming somehow that only you have
> > magical and more correct solutions seems to show that working with
> > you isn't going to happen.
> I'm not claiming we have a monopoly on brains. I'm claiming FreeBSD
> has never been ported to anything other architecture from its Wintel
> base. Do you dispute this?
I am going to frame your first sentence, simply because it is
seldom heard from a NetBSD person.  A FreeBSD kernel is soon to run
on an Alpha, but why should you care, since FreeBSD is so inferior,

> > We certainly don't want to be constrained
> > by the limitations of an OS that has lots of ports...  sort of...
> Sort of?
Well I know of and used a couple of NetBSD ports that do not
meet the standards that I feel would be sufficient for FreeBSD...
One of them is the X86 port, and the other one, I will not say,
because I like and respect the ports-meister so much.  It isn't
his fault about the limitations of the rest of the system though.

> > This is a quality vs. quantity argument.  I suggest that there
> > is a difference between "working" and "WORKING."
> Our code base is of extremely high quality. That has cost us over the
> long run, but it has been worth it.
Code base doesn't mean anything to me, when the results do not
meet my standards.  Form vs. substance.

I have been helping with a little NetBSD hacking, and frankly, I would
be very embarassed about the way the code works.  Of course, we fixed
most of those problems in FreeBSD.

I do like some of the abstractions in the internals, and some of those
ideas should be adopted by FreeBSD.  However, I really want to do it
right this time.

John                  | Never try to teach a pig to sing,     | it just makes you look stupid,         | and it irritates the pig.