Re: [Qemu-devel] [PATCH v10 5/8] module: implement module loading

[Alex Bligh]

On 17 Sep 2013, at 06:55, Fam Zheng wrote:

>>> 
>>> I think I'd just have one flat list
>>> of modules to load and ditch these  MODULE_LOAD_XXXX enums.
>> 
>> Question is how to deal with qemu vs. qemu-img then.  qemu needs
>> everything and qemu-img needs the block drivers only (and loading
>> something else probably doesn't work due to unresolved symbols).
>> 
> 
> With lazy symbol binding (G_MODULE_BIND_LAZY), we can just load all the
> modules, and wait for subsystem to call module_call_init(MODULE_INIT_*), where
> the symbols are resolved. As qemu-img.c doesn't init ui, net, it's not a
> problem to load them ahead.

Why not have one list per executable you build? You know at compile
time what modules each executable could load. This seems better
than putting the logic in and run time and having different types
of modules etc.

One reason to avoid qemu-img (for instance) loading everything (if
it's present) is init time. I agree dlopen()'ing something that
never gets called should not eat too much RAM but it seems pointless.

-- 
Alex Bligh