lkml.org 
[lkml]   [2003]   [Jan]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC] Migrating net/sched to new module interface
Date
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/

\
 
 \ /
  Last update: 2005-03-22 13:32    [W:0.151 / U:2.608 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site