Re: [dpdk-dev] [PATCH] mk: fix kernel modules build dependency

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 3/30/2018 9:32 AM, Thomas Monjalon wrote:
> 29/03/2018 20:43, Ferruh Yigit:
>> On 3/29/2018 7:21 PM, Ferruh Yigit wrote:
>>> On 3/29/2018 6:01 PM, Thomas Monjalon wrote:
>>>> 29/03/2018 18:50, Ferruh Yigit:
>>>>> On 3/29/2018 5:43 PM, Thomas Monjalon wrote:
>>>>>> 29/03/2018 18:38, Ferruh Yigit:
>>>>>>> On 3/29/2018 5:32 PM, Thomas Monjalon wrote:
>>>>>>>> 29/03/2018 17:48, Ferruh Yigit:
>>>>>>>>> On 3/29/2018 4:39 PM, Thomas Monjalon wrote:
>>>>>>>>>> Some kernel modules may need some header files to be "installed"
>>>>>>>>>> in the build directory.
>>>>>>>>>>
>>>>>>>>>> When running multiple threads of make, kernel modules can try to
>>>>>>>>>> be compiled before the lib headers are ready:
>>>>>>>>>> 	make -j3
>>>>>>>>>> 	kernel/linux/kni/kni_misc.c:19:37: fatal error:
>>>>>>>>>> 		exec-env/rte_kni_common.h: No such file or directory
>>>>>>>>>
>>>>>>>>> Is there a reason to keep header in eal when module itself moved into kernel?
>>>>>>>>
>>>>>>>> It seems you missed my comment below:
>>>>>>>>
>>>>>>>> On a related note, this header file
>>>>>>>>         lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
>>>>>>>> could be moved to lib/librte_kni/
>>>>>>>> Opinion?
>>>>>>>
>>>>>>> Ahh, yes we are saying same thing.
>>>>>>> But not sure if it should go under lib/librte_kni/ or kernel/linux/kni/?
>>>>>>> I lean to kernel/linux/kni/.
>>>>>>
>>>>>> Why in kernel/?
>>>>>>
>>>>>> Logically, kernel/ depends on lib/ but not the reverse.
>>>>>>
>>>>>> And regarding the licensing, we avoid BSD files in Linux modules.
>>>>>
>>>>> From functionality point of view, module provides the functionality and it
>>>>> should provide the header, this can be all subjective tough :)
>>>>>
>>>>> Or in other words, if you have the kernel module, you can write another piece of
>>>>> userspace application (without using librte_kni) and it will be functional.
>>>>> But if you have the librte_kni only, it won't be functional on its own.
>>>>>
>>>>> Providing header with kernel enables other userspace app to user KNI.
>>>>
>>>> So you are saying we should reverse the dependency?
>>>> It would mean moving all headers used by kernel modules in kernel/ directory:
>>>
>>> No, not talking about moving headers to kernel/ folder. But we can "liberate" J
>>> the kernel modules.
>>>
>>> For KNI, rte_kni_common.h is shared between kernel and userspace, can't escape
>>> from it. But why this common header needs to depend other dpdk headers at all?
>>> Indeed commenting out rte_common and rte_config worked fine, it seem there is
>>> already no dependency.
>>
>> Hemant is right, putting rte_kni_common makes build dependent to module build,
>> and module is more fragile.
>>
>> I agree to move header to userspace library.
> 
> Does it mean you ack this patch?

yep,
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>

> 
> Do you want to make a patch to move the header from EAL to librte_kni?
> 
> 
>