Re: [PATCH] port: fix build when KNI support is not enabled

[Olivier Matz <olivier.matz@6wind.com>]

Hi Bruce,

On 06/23/2016 10:53 AM, Bruce Richardson wrote:
>>> If we want to specifically build this directory, why preventing us to do
>>> so with CONFIG_RTE_LIBRTE_PORT?
>>
>> If we call foo_sub with CONFIG_FOO=n, it will generate a library and
>> install headers in the build directory, however the config is unset.
>> Some propositions if we want to replace
>> DEPDIRS-$(CONFIG_RTE_LIBRTE_PORT) by DEPDIRS-y:
>>
>> 1/ say that "make foo_sub" should be used with care, only if CONFIG_FOO
>>    is set (else it is not supported) -> nothing to do
>> 2/ fix the make %_sub feature to browse parent directories, checking
>>    the SUBDIRS-${CONFIG_FOO}
>> 3/ remove the make %_sub feature, maybe nobody cares...
>>
>> I think 1/ is acceptable.
> 
> +1
> 
> Especially given the fact I wasn't even aware that you could do that (building
> just one subdir). Do we have a usecase where people might want to build just one
> DPDK subdirectory?

The only use-case I see is to gain few seconds when recompiling: it can
avoid to check deps in all directories if you know that your
modifications only take place in a specific directory.

Well, nothing really essential ;)