Re: [dpdk-dev] kernel binding of devices + hotplug

[Bruce Richardson <bruce.richardson@intel.com>]

On Fri, Apr 13, 2018 at 06:31:21PM +0200, Thomas Monjalon wrote:
> It's time to think (again) how we bind devices with kernel modules.
> We need to decide how we want to manage hotplugged devices with DPDK.
> 
> A bit of history first.
> There was some code in DPDK for bind/unbind, but it has been removed
> in DPDK 1.7 - http://dpdk.org/commit/5d8751b83
> Copy of the commit message (in 2014):
> "
> 	The bind/unbind operations should not be handled by the eal.
> 	These operations should be either done outside of dpdk or
> 	inside the PMDs themselves as these are their problems.
> "
> 
> The question raised at this time (4 years ago) is still under discussion.
> Should we manage binding inside or outside DPDK?
> Should it be controlled in the application or in the OS base?
> 
> As you know, we use dpdk-devbind.py.
> This tool lacks two major features:
> 	- persistent configuration
> 	- hotplug
> 
> If we consider that the DPDK applications should be able to apply its own
> policy to choose the devices to bind, then we need to implement binding
> in the PMD (with EAL helpers).
> 
> On the other hand, if we consider that it is the system responsibility,
> then we could choose systemd/udev and driverctl.
> 
> The debate is launched!
> 

Allow me to nail my colours to the mast early! :-)

I believe it's system not application responsibility.
I also believe I have previously explained my reasons for that choice in
some of the previous email threads.

/Bruce