question about building a module

[devendra.aaru]

On Sat, Dec 8, 2012 at 3:03 AM, Yann Droneaud <ydroneaud at opteya.com> wrote:
> Le vendredi 07 décembre 2012 à 20:44 +0200, Kevin Wilson a écrit :
>> Hi,
>>
>>
>> I am adding some code of my own **only** under
>> net/bluetooth in some file there.
>>
>>
>> There is only exactly one module which is changed by my addition,
>> This is net/bluetooth/bluetooth.ko
>>
>>
>> Now, when I run 'make -j2 modules' it takes quite a time, even If I
>> did one change in one line in a file under net/bluetooth.
>>
>>
>> I assume that it has to do with stage 2 of the build, which says
>> something about
>> ...
>>   Building modules, stage 2.
>>   MODPOST 855 modules
>> ...
>> see below full log.
>>
>>
>> Now my question is this:
>> Is there a way to make things more efficent when building a module, on
>> the
>> assumption that I do not change anything anywhere
>> except /net/bluetooth (in this case)?
>>
>>
>> somehow telling the MODPOST  that only one module is changes ?
>>
>>
>> I remember I once saw (not sure) a suggestion to build only a
>> specified moule like:
>> make net/bluetooth
>> But in this case the result is the same.
>>
>
> cd net/bluetooth
> make -C $PWD/../../ M=$PWD modules
>
> (But if you change a configuration parameter in .config,
> you will need to do a full build)

why? is that creates a linker errs while your module uses some symbols
that are not exported?

>
> Regards.
>
> --
> Yann Droneaud
> OPTEYA
>
>
>
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