Re: modutils-970118 problem

Kevin Lentin (kevinl@cs.monash.edu.au)
Wed, 22 Jan 1997 11:45:07 +1100 (EST)


Richard Henderson Wrote ...
>
> > I'm surprised the used count on cdrom isn't at least one. And why don't
> > sr_mod and isofs get unloaded? Is it because the mount failed?
>
> Ah, that isn't a used count, but a use count. It is not in use
> at the moment.

So the use count doesn't include the module dependancies? If sr_mod depends
on cdrom and cdrom is marked as [sr_mod] should that not count as 1 in the
use count.

> As to why sr_mod and isofs don't get unloaded, it is a feature of the new
> module system that is trying to prevent a race condition in kerneld.

> What would happen is, on some IDE systems, it would take some time (more
> than a minute) for the CD to come on line and begin reading data. In the
> meantime, the isofs module got unloaded and so the mount failed. This
> would happen over and over.
>
> So The Plan is that kerneld won't automatically unload a module that has
> never been used, so that we don't run into that situation.
>
> I'm not sure how far along the chain you have to go in the scsi subsystem
> before the bits trip to say that the module is in use, but at this point
> I can only presume it wasn't far enough.

Cool idea. Maybe we could have an option in the config file which could
specify a different wait time for different modules so people with slow
devices could set the timeout on those modules to 2 minutes, for instance.

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