Re: The advantage of modules?

[Ookhoi]

Hi Michael,

> On Fri, Jan 05, 2001 at 10:50:20PM -0600, Evan Thompson wrote:
> > I'd like to know (I know, I'm being slightly off topic, while still
> > staying on topic, so I'm on topic...er...yes) if there is any
> > advantage, be it memory-wise or architectuarally wise, to use
> > modules?
> > 
> > I already know the obvious points of if you are creating a distro
> > that it is usually good to make a very modular kernel for those
> > wishing not to recompile their kernel, but I was wondering if there
> > were any other advantages to using modules vs. making a monolithic
> > kernel for a kernel to be used only on one machine (with no other
> > hardware support at all)?
> 
> A couple of thoughts:
> 
>    1)	A full kernel with everything compiled in might not fit on boot
>    media such as floppies, while modules allows you to not load stuff
>    that isn't needed to until after the main booting is accomplished.
> 
>    2)	There are several devices that have multiple drivers (such as
>    tulip, and old_tulip for example).  Which particular driver works
>    depends on your exact particular hardware.  If both of these
>    drivers are linked into the kernel, whatever the kernel chooses to
>    initialize first will talk to the device.
> 
>    3)	Having drivers as modules means that you can remove them and
>    reload them.  When I was working in an office, I had one scsi
>    controller that was a different brand (Adaptec) than the main scsi
>    controller (TekRam), and I hung a disk in a removable chasis on the
>    scsi chain in addition to a tape driver and cd-rom.  When I was
>    about to go home, I would copy all of the data to the disk, unmount
>    it, and then unload the scsi device driver.  I would take the disk
>    out, and reload the scsi device driver to get the tape/cd-rom.  I
>    would then take the disk to my home computer.  I would reverse the
>    process when I came in the morning.

You don't need modules for this to work.

		Ookhoi