Re: [PATCH] mk: fix kernel modules build dependency

[Thomas Monjalon <thomas@monjalon.net>]

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?

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