Re: 2.6.4, or what I still don't quite like about the new stablebranch

From: Peter Williams
Date: Mon Mar 15 2004 - 19:59:28 EST


Grzegorz Kulewski wrote:
4. Module autounloading. Is it actually possible? Will it be possible?
If not, why? The old method of periodically invoking "modprobe -ras" via
cron doesn't seem to accomplish anything and I really liked the idea of
keeping only the required modules in memory at any given moment without
having to log in as root to unload the unneeded ones - after all, if the
autoloader can only add them what's the point of not going the
monolithic way? The docs on the new approach towards modules are
virtually nonexistent in the kernel source package and while I suppose I
could simply write a script which would scan the list of
currently-loaded modules for the unused ones and remove them one by one,
but this approach feels terribly crude comparing with the elegance of
the old solution. I use module-init-tools-3.0, a serious improvement
over 0.9.15 if I may say so but, unless I'm thinking about it with
completely wrong base assumptions, still far from perfect.


As far as I know, the new preffered way of handling modules, is to load them when device is detected (hotplug and udev, at boot or later) and (optionally) remove when device is removed, not as in older kernels, when module was added or removed depending on its use. This way (as opposed to monolithic kernel) you can have "generic" kernel by placing everything in modules. And what is the point in unloading not currently needed modules?

It enables you to update a module (e.g. to fix a bug) without having to do a reboot. I think that people trying to use Linux for useful work would find this useful. So unloadable modules is certainly a functionality worth aiming for.

They should not use much resources when not needed...
And if you want to put your system to sleep, you must put to sleep all devices (in the right order) *including* these not currently used but present in the system. If you will not do this, you can probably get big crash. So you need loaded module, that knows how to put device to sleep.


Grzegorz Kulewski

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