[dpdk-dev] rte_kni.ko with lo_mode=lo_mode_ring

[Wiles, Keith]

HI Gary,

Regards,
Keith

> On Sep 2, 2016, at 8:39 AM, Mussar, Gary <gmussar at ciena.com> wrote:
> 
> The pktgen docs state that the rte_kni.ko should be loaded with lo_mode=lo_mode_ring however the source in dpdk master does not appear to understand this value. This wasn't an issue in the past since the kni code would simply disable lo_mode if you passed in an unknown value.
> 
> The Ubuntu 4.4.0-36-generic kernel no longer loads the module if the passed value is not in the table of known values (the 4.4.0-34-generic kernel would still load the module).
> 
> I have 2 questions:
> 1)
> Why does pktgen specify using a value for lo_mode that the source does not support? Is lo_mode_ring something that is coming but not yet submitted?

The KNI support and kernel module is more of a DPDK issue then Pktgen, which is the application on top of DPDK. I do not know the reason lo_mode_ring is not working correctly. Look in the Maintainers file and see who maintains the KNI code.

> 
> 2)
> Is the Ubuntu kernel being over aggressive in parameter checking or is this a "good" thing? If it is good, then should the pktgen docs be indicating that an unsupported value be used for lo_mode?

I assume the Ubuntu Kernel is attempting to protect itself. Each time the kernel is updated it is a good think to recompile DPDK and the KNI kernel module or the module may not load because of a version mis-match.

> 
> Gary