Subject: Re: dynamic configuration (was Re: PR#4094)
To: Matthew Orgass <darkstar@pgh.net>
From: Michael Richardson <mcr@sandelman.ottawa.on.ca>
List: tech-kern
Date: 10/22/2000 22:35:05
>>>>> "Matthew" == Matthew Orgass <darkstar@pgh.net> writes:
Matthew> On Sun, 8 Oct 2000, Michael Richardson wrote:
>> My desire is to be able to build *static* kernels from CD. While being able
>> to load modules for devices is nice during testing, the infrastructure for
>> adding things to autoconf is not that at present. I'd dearly like to add it,
>> but I think this will be a tempest in a teacup...
Matthew> Usually once you pay the price of being able to dynamically load
Matthew> something, there is little if any gain in separating the static part.
Huh?
Matthew> Whether the kernel is static or dynamic should just affect when the
Matthew> modules are linked, not what acutally happens. Unless there is a
Matthew> significant performance difference, it isn't worth being able do to things
Matthew> both ways.
Please explain further.
There are significant reliability and maintenance issues with dynamic
loading. Witness DLL rot, and Linux in general.
>> >> But, I'd rather have all of this explicit in a config file
>>
Matthew> If you use init sections properly, you don't need config files at all.
>>
>> I *LIKE* the config files. They are very useful. It needs to be easier to,
>> e.g. remove all PCMCIA devices for a machine that doesn't have that bus, but
>> that is still nice.
Matthew> The nice thing is you don't *need* config files. You could just link in
Matthew> a module and have it work. However, on further thought init sections are
I *WANT* config files.
I do not want things to magically happen. That way lies Windows.
Matthew> I think one requirement in any serious move towards dynamic
Matthew> configuration should be the ability to create a statically linked kernel
Matthew> with only object files and a linker. As long as things like DEBUG and
Matthew> DIAGNOSTIC are defined at compile time, it should not be that difficult to
Matthew> do (though it would still involve a fair number of changes). Config info
Matthew> could be written with linker scripts.
Please explain further.
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