Re: [PATCH v2] mk: optimize directory dependencies

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

Hi Ferruh,

On Tue, 28 Mar 2017 11:34:35 +0100, Ferruh Yigit <ferruh.yigit@intel.com> wrote:
> On 3/24/2017 1:21 PM, Olivier Matz wrote:
> > Before this patch, the management of dependencies between directories
> > had several issues:
> > 
> > - the generation of .depdirs, done at configuration is slow: it can take
> >   more than one minute on some slow targets (usually ~10s on a standard
> >   PC without -j).
> > 
> > - for instance, it is possible to express a dependency like:
> >   - app/foo depends on lib/librte_foo
> >   - and lib/librte_foo depends on app/bar
> >   But this won't work because the directories are traversed with a
> >   depth-first algorithm, so we have to choose between doing 'app' before
> >   or after 'lib'.
> > 
> > - the script depdirs-rule.sh is too complex.
> > 
> > - we cannot use "make -d" for debug, because the output of make is used for
> >   the generation of .depdirs.
> > 
> > This patch moves the DEPDIRS-* variables in the upper Makefile, making
> > the dependencies much easier to calculate. A DEPDIRS variable is still
> > used to process library dependencies in LDLIBS.
> > 
> > After this commit, "make config" is almost immediate.
> > 
> > Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
> > Tested-by: Robin Jarry <robin.jarry@6wind.com>
> > Tested-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>  
> 
> <...>
> 
> >  DIRS-$(CONFIG_RTE_LIBRTE_PORT) += librte_port
> > +DEPDIRS-librte_port := librte_eal librte_mbuf librte_mempool librte_ether
> > +DEPDIRS-librte_port += librte_ip_frag librte_sched librte_kni  
>                                                          ^
> ---------------------------------------------------------+
> 
> <...>
> 
> > diff --git a/lib/librte_port/Makefile b/lib/librte_port/Makefile
> > index 44fa73520..76629a13a 100644
> > --- a/lib/librte_port/Makefile
> > +++ b/lib/librte_port/Makefile  
> <...>
> > -ifeq ($(CONFIG_RTE_LIBRTE_KNI),y)
> > -DEPDIRS-$(CONFIG_RTE_LIBRTE_PORT) += lib/librte_kni
> > -endif  
> 
> This check needs to be reflected to new method, otherwise causing build
> errors for i686 target.
> 

Did you notice an error? I see no error it with:

    make config T=x86_64-native-linuxapp-gcc
    sed -i 's,CONFIG_RTE_LIBRTE_KNI=y,# CONFIG_RTE_LIBRTE_KNI is not set,' build/.config
    make -j8


I think it is not a problem, the DEPDIRS-* variable only gives an
ordering directive, which should be ok even if kni is not compiled.


Regards,
Olivier