Messages in this thread | ![/](/images/icornerl.gif) | | From | Rusty Russell <> | Subject | Re: [RFC] Migrating net/sched to new module interface | Date | Wed, 15 Jan 2003 19:16:24 +1100 |
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In message <20030115043147.A1840@almesberger.net> you write: > kuznet@ms2.inr.ac.ru wrote: > > Somewhat overdone. > > I think it would be nice to introduce in 2.7 a shutdowncall > (*) function class for modules that works like exitcall, but > with the following differences: > > - does not return before the module has really de-registered > itself everywhere, including synchronization with any > callbacks, etc. > - has a return code, and can fail if it would have to sleep > for a possibly long time > > Before calling the shutdown function, all symbols exported by > the module are hidden, and after the shutdown functions returns, > the module can be unloaded.
This already happens. This is why all accesses to the module are protected by try_module_get().
I've analyzed dozens of "here's my implementation idea" mails over the last two years. Here's the executive summary:
1) It's simply not a good idea to force 1600 modules to change, no matter what timescale. And changing it in a way that is *more*, not *less* complex is even worse.
2) It's bad enough to force the interfaces to change: at least the primitive they are to use is one many of them are already using, and is very simple to understand.
Rusty. PS. The *implementation* flaw in your scheme: someone starts using a module as you try to deregister it. Either you re-register the module (ie. you can never unload security modules), or you leave it half unloaded (even worse). -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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