[ovs-dev] [PATCH 0/2] Deprecate the Linux OOT driver

[Ilya Maximets]

On 1/6/21 7:09 PM, Gregory Rose wrote:
> 
> 
> On 1/6/2021 4:34 AM, Ilya Maximets wrote:
>> On 1/5/21 7:33 PM, Greg Rose wrote:
>>> As agreed in (1) deprecate the Linux OOT driver.
>>>
>>> github Build and Test here:
>>> https://github.com/gvrose8192/ovs-experimental/actions/runs/463987690
>>>
>>> 1. https://mail.openvswitch.org/pipermail/ovs-dev/2020-December/378831.html
>>>
>>> Greg Rose (2):
>>>    doc: Deprecate the Linux Out of Tree drivers
>>>    acinclude: Warn when --with-linux parameter is supplied
>>>
>>>   Documentation/faq/releases.rst | 7 ++++++-
>>>   NEWS                           | 3 +++
>>>   acinclude.m4                   | 1 +
>>>   3 files changed, 10 insertions(+), 1 deletion(-)
>>>
>>
>> Thanks for the patches!
>>
>> Few general comments:
>>
>> 1. Word 'driver' sounds weird to me.  'kennel module' is more commonly
>>     used term, I think.  We're using term 'driver' for windows datapath,
>>     but it seems like windows-specific thing.  In Linux world 'driver' is
>>     usually something that talks directly to hardware and that is not
>>     the case for openvswitch.ko and other parts.
>>     I'd say that we need to do s/kernel driver/kernel module/ in this
>>     patch set.
> 
> Sure, not a problem.
> 
>>
>> 2. We need to specify the date of removal in NEWS and docs.  I'd say
>>     that we could state that OOT kernel module will be removed in 2.16.
>>     BTW, from the development point of view it might be good to remove
>>     it as soon as 2.15 branched/released.
> 
> Do we actually want to remove it or just leave it deprecated but still there?
> 
> And when we say remove it does that mean just disable the '--with-linux'
> configure option or would we be removing all the code as well?  I just
> want to make sure we define removal the same way.

My understanding is to completely remove all the related code and documentation.
This includes 'datapath' directory and configuration stuff from m4 files.

Users will be able to build kernel module from the 2.15 branch.  This way
we will not need to maintain duplicate of the code on newer branches.

One problem here is that OVS 2.15 will reach EOL relatively soon, and projected
EOL for kernel 5.4 is Dec 2025.  We might actually postpone complete removal
until 2.18.  This way we will have OVS 2.17 LTS with kernel module included.
And it will be supported until Feb 2025.  And we might actually increase
support time on branch-2.17 just for kernel module until kernel 5.4 reaches EOL.
After that we can safely remove OOT module in OVS 2.18, because there will
be no supported upstream kernel at this point that OOT module supports.

Thoughts?

If that's OK, we can just state in NEWS and documentation that OOT kernel
module will be removed in OVS 2.18 and keep it until then.

Best regards, Ilya Maximets.