On Wed, 2008-06-18 at 10:57 +0200, Geert Uytterhoeven wrote: > On Wed, 18 Jun 2008, Adrian Bunk wrote: > > On Wed, Jun 18, 2008 at 09:20:22AM +0100, David Woodhouse wrote: > > > On Wed, 2008-06-18 at 09:47 +0300, Gilad Ben-Yossef wrote: > > > > This may sound like a stupid question, but why are you compiling the > > > > modules statically? > > > > > > I wondered that. > > > > > > One potential reason to avoid modules is that they waste RAM -- you have > > > to allocate an integral number of pages for each one, which means an > > > average of 2KiB wasted for each module you load. Although that isn't > > > much, it's not zero either. It might be possible to optimise that by > > > 'packing' module allocations, if you're careful about it. > > >... > > > So the only real reason I can see to avoid modules in the _current_ > > > kernel would be the wasted RAM, which should be something we can > > > address. > > >... > > > > You miss the size increase imposed by CONFIG_MODULES=y. > > > > E.g. setting CONFIG_MODULES=y in the arm collie_defconfig will > > increase the size of vmlinux by 14% (sic). > > > > I haven't investigated why it takes that much space, but stuff like > > kernel/module.o taking 23kB and each EXPORT_SYMBOL requiring a few > > bytes simply cannot be completely eliminated. > > Sounds like we need a tool that strips out the unneeded symbols, given a list > of modules? And do the --gc-sections step again after that... :) -- dwmw2 -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
