Raw-device-war (was Re: Sharing SCSI disks)

Mikko Ala-Fossi (malafoss@cc.hut.fi)
Wed, 26 Mar 1997 14:10:52 +0200 (EET)


On Tue, 25 Mar 1997, David S. Miller wrote:

> Date: Tue, 25 Mar 1997 14:25:38 -0800 (PST)
> From: Michael Neuffer <neuffer@nomis.i-Connect.Net>

> On Tue, 25 Mar 1997, Illuminati Primus wrote:
> > However, unlike an MS OS, you are always free to join in the development
> > effort. If RAW IO in linux is important to you, you could always help
> > implement it instead of continue to whine about its absence.

> We did, it got stopped cold it its tracks by Linus.

> Since when does pinhead Torvalds completely control what features
> Linux provides for "everyone" on the planet? He never has and he
> never will.

Since this raw-device-war is going personal and is going to last
till someone is dead, I have a proposal.

Raw-device support could be done as a kernel module and only
necessary hooks should be made to the kernel itself. Since
there is a danger that people who don't _really_ need those
raw devices will try to use them to speed up their applications,
it should be made difficult to use raw-device and it should
not be default or automatic behaviour of the kernel.

We don't want MS-DOS syndrome where every application has
access to raw-devices and do their own hardware drivers.
Whole idea of Linux is that hardware and raw devices are
centralized under kernel control to provide certain common
services to these devices that are buffered and optimized
to the last byte. (however GGI follows idea presented but
it is not added to the kernel, that's why we have too diverce
support for graphics)

There are few ways to do support for raw devices without adding
it to the official kernel itself:
1. Maintain your own patches to linux kernel to do support for raw devices.
2. Try to convince kernel maintainers to add hooks and do your own module
(distributed as a separate source file).

Hooks for the raw-device support should however be under kernel option
and should default to not to support raw-devices. I think it is not
wise to add straight raw-device support to kernel, because it is a
message to application programmers to start using their own buffer-
routines to optimize their application performance.

-=- malafoss@cc.hut.fi -=- searching the marvels of universe -=-