Re: Kernel Module dependency in DPDK 18.05-rc5 and earlier DPDK releases

[Thomas Monjalon <thomas@monjalon.net>]

25/05/2018 15:57, Bruce Richardson:
> On Fri, May 25, 2018 at 04:20:42PM +0300, Kevin Wilson wrote:
> > Thanks, Thomas.
> > 
> > Actually there is an EAL rte_eal_check_module() method which does this exactly:
> > http://dpdk.org/browse/dpdk/tree/lib/librte_eal/linuxapp/eal/eal.c#n1089
> > It is declared in eal_private.h.
> > 
> > Is it reasonable to send a patch which moves the decalartion to eal.h
> > instead so PMDs can use it in their probe() method ?
> > 
> > Apart from it -  So is there any practical effect for using the
> > RTE_PMD_REGISTER_KMOD_DEP() ? or is it only a sort of declarative
> > macro, saying that the PMD is dependent on the specified kernel
> > modules ? In the past - did it really ever check for dependency and
> > shouted back
> > when the required modules specified in the RTE_PMD_REGISTER_KMOD_DEP()
> > macro were not found ?
> > 
> AFAIK this information is only used for reporting out when running pmdinfo
> on a driver or statically linked binary. It was never enforced at runtime,
> simply because the lack of particular ports was never an error. If a module
> was not loaded, and NICs not bound to that module, it was always assumed
> that the ports were never meant to be used by DPDK anyway.

Yes it is informational.
But we can add a log to help with debug.
It could even be an error if a port is whitelisted.