Re: Modular raidframe

[Paul Goyette <paul%vps1.whooppee.com@localhost>]

On Sun, 20 Dec 2015, Michael van Elst wrote:

> paul%whooppee.com@localhost (Paul Goyette) writes:
>
> > The attached diffs (plus 2 new files) convert our existing raidframe
> > driver into a loadable module.
>
> Does this still work with a non-MODULAR kernel?


Short answer: Yes

More details:

Whether or not a kernel is built with "options MODULAR", it still 
contains modules.  The only thing that the option controls is whether or 
not the in-kernel linker is included.  Code that has been modularized is 
included as a built-in module (and initialized as such) regardless of 
the option.

So the classes of kernels are:

non-MODULAR - "no options MODULAR"

	These kernels have a static configuration, defined at build
	time.  They cannot be extended at boot- or run-time since
	there is no linker included.  Built-in modules are still
	treated as modules, initialized by module_init() (called from
	init_main()), etc.  And built-in modules can still be disabled
	with the modunload(8) command.

MODULAR - "option MODULAR"

	These kernels include an in-kernel linker which can be used
	to add additional code at run-time.  Typical GENERIC kernels
	generally fall into this class, even though nearly everything
	is already linked in at build time.  On -current amd64, we
	include almost 150 built-in modules.

I like to think that I run a kernel from a third class:

HIGHLY-MODULAR

	These kernels include only a minimum amount of built-in code,
	and any additional functionality is loaded as needed.  I have
	fewer than 20 built-in modules, and generally run with only
	40 modules total (the difference being loaded dynamically).



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