Kernel modules - documentation?

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

Is there any documentation on the modules interface or API?  There does 
not seem to be anything in the man pages...
My specific questions:

What actually triggers an autoload of a module?  (There seem to be very 
few places where module_autoload() is called.)
What is the semantic difference between module_autoload() and a "normal" 
module_load()?
Does the code which calls either of these routines need to be concerned 
with whether the module has been previously loaded?  Is it OK to load a 
module that has already been loaded?
Given that there is a kernel thread that runs around and attempts to 
unload any unreferenced modules that have been loaded "for a while", is 
it ever necessary or desirable to explicitly unload a module?
What happens if a global symbol referenced by a module doesn't exist? 
Does the module get loaded anyway, leaving the reference unresolved?

Thanks in advance!


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