Subject: Re: Increasing maximum partition to 16
To: Chuck Silvers <>
From: Greywolf <>
List: tech-kern
Date: 12/28/2000 20:47:05
On Thu, 28 Dec 2000, Chuck Silvers wrote:

# the fact that people want this feature right now does not justify
# making incompatible changes that are clearly not the best solution.
# back when ISA DMA was still an important issue for many people,
# people wanted bounce-buffering "right now".  rather than just hack all
# the relevant drivers to provide that, NetBSD designed and implemented
# the bus_dma framework, which has been a far superiour solution in the
# long run.  why would we start making design decisions based on expediency
# now?  and changing the interpretation of device minor numbers has a far more
# significant downside than the choice of ISA bounce-buffering schemes,
# since the changing the interpretation of device minor numbers is visible
# to applications and it breaks existing usage.

Chuck, I realise the tone of my most recent message must have sounded
quite disparaging, and I apologise for that.  It should be POSSIBLE
at some point to do the volmgr thing, yes, but don't mandate it.  Please.
It's overhead respective either to space or time, and it would be nice
to be able to bypass it.  Besides that, it would be something that the
bootloader would need compiled in?

With respect to the bounce buffer issue, NetBSD very nearly lost a large
crowd of people with sub-standard machinery because while we were doing
The Right Thing, we were doing it at a slow pace.  IIRC, we were working
on the bounce buffers at the time when PCI was just starting to make serious
headway, so I think a lot more development effort was going to making the
PCI stuff work (correct me if I'm wrong; my memory is developing ECC
errors as I get older).  By the time the bounce buffers were ready to use,
the hardware on which it would run had long been outstripped.

I still think it was probably the right thing to do, but how do you weigh
a success in that manner?

On the partitioning issue, that's something that's not going to suddenly
go away.  16 partitions, for the moment, ought to be enough.

[but how's the bootloader going to deal with that one, especially
on the Suns?]

# -Chuck

*BSD: a devil of an operating system.