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

[Fam Zheng]

On Tue, 09/17 07:33, Alex Bligh wrote:
> 
> 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.
> 

OK, good point.

Fam