Messages in this thread | | | Subject | Re: [patch 1/8] Immediate Values - Global Modules List and Module Mutex | From | Rusty Russell <> | Date | Tue, 11 Sep 2007 09:53:34 +1000 |
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On Sat, 2007-09-08 at 11:28 +0400, Alexey Dobriyan wrote: > On Thu, Sep 06, 2007 at 04:02:29PM -0400, Mathieu Desnoyers wrote: > > Remove "static" from module_mutex and the modules list so it can be used by > > other builtin objects in the kernel. Otherwise, every code depending on the > > module list would have to be put in kernel/module.c. Since the immediate values > > depends on the module list but can be considered as logically different, it > > makes sense to implement them in their own file.
If I understand this code correctly, then changing immediate values needs some exclusion to avoid patching live code. You leave this to the user with some very unclear rules.
The result is a real mess that has nothing to do with the module mutex and list. These patches need a lot more work 8(
1) The immediate types are just kind of silly. See per-cpu for how it handles this already. DECLARE_IMMEDIATE(type, var) is probably enough.
2) immediate_if() needs an implementation before you introduce it. Your assumption that it's always unlikely seems non-orthogonal.
3) immediate_set(), _immediate_set() and immediate_set_early()? No thanks! AFAICT you really want an "init_immediate(var, val)". This means "you can patch all the references now, they're not executing". Later on we could possibly have a super-stop-machine version which ensures noone's preempted and handles the concurrent case. Maybe.
4) With an "init" interface not a "set" interface, you don't need locking. Simpler.
Hope that helps, Rusty.
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