[dpdk-dev] IGB_UIO port unbinding

[Stephen Hemminger]

On Mon, 14 Apr 2014 08:57:54 +0000
"Burakov, Anatoly" <anatoly.burakov at intel.com> wrote:

> Hi Stephen,
> 
> > I actually liked the unbind code that was there. It meant that additional logic
> > did not have to be added to the startup script to do PCI discovery and
> > finding/mapping devices.
> > 
> > As it is the EAL startup process is a bit of a mess. It assumes that various bits
> > of information and infrastructure are already in place prior to starting the
> > DPDK application.
> 
> I would argue that it's not the responsibility of the application to set up its environment. The EAL startup process is indeed a bit all over the place, but the alternative would be worse. Those "various bits of information and infrastructure" you're referring to include, say, hugepages - I don't think it's a good idea for an application to meddle with system's hugepages any more than I think it's a good idea for it to meddle with the driver bindings.
> 
> Plus, current state of affairs makes for headaches in the future when support for other drivers is implemented (say, VFIO). It's much better to move the responsibility of binding the drivers to the user, and DPDK provides quite convenient means to do that (the PCI binding Python script) and also a centralized script to prepare the DPDK environment without much hassle (the setup.sh).
> 
> Best regards,
> Anatoly Burakov
> DPDK SW Engineer
> 

The problem is that doing the initialization requires duplicating all the
logic to probe the PCI bus and do blacklisting etc in the startup application.