Re: [PATCH] doc: update minimum Linux kernel version

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 16 Feb 2024 09:29:47 +0100
Morten Brørup <mb@smartsharesystems.com> wrote:

> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Friday, 16 February 2024 04.05
> > 
> > On Thu, 11 Jan 2024 23:38:07 +0100
> > Morten Brørup <mb@smartsharesystems.com> wrote:
> >   
> > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > > Sent: Thursday, 11 January 2024 20.55
> > > >
> > > > On Thu, 11 Jan 2024 20:26:56 +0100
> > > > Morten Brørup <mb@smartsharesystems.com> wrote:
> > > >  
> > > > >
> > > > >
> > > > > When the documentation specifies a minimum required kernel  
> > version,  
> > > > it implicitly claims that DPDK works with that kernel version.  
> > > > >
> > > > > So we should either test with the specified kernel version (which  
> > > > requires significant effort to set up, so I’m not going to ask for
> > > > it!), or add a big fat disclaimer/warning that DPDK is not tested  
> > with  
> > > > the mentioned kernel version, and list the kernel versions actually
> > > > tested.
> > > >
> > > > It is much less of an issue than it used to be since there should  
> > be no  
> > > > need for
> > > > DPDK specific kernel components. The kernel API/ABI is stable  
> > across  
> > > > releases
> > > > (with the notable exception of BPF). Therefore the DPDK kernel  
> > version  
> > > > dependency
> > > > is much less than it used to be.  
> > 
> > There are three issues here:
> > 
> > 1. Supporting out of date kernel also means supporting out of date
> > build environments
> >    that maybe missing headers. The recent example was the TAP device
> > requiring (or cloning
> >    which is worse) the headers to the FLOWER classifier.  If we move
> > the kernel version
> >    to current LTS, then FLOWER is always present.
> > 2. Supporting out of date kernel means more test infrastructure. Some
> > CI needs to build
> >    test on older environments.
> > 3. The place it impacts current CI is the building on CentOS7. CentOS7
> > is end of life
> >    do we have to keep it? The compiler also lack good C11 support so
> > not sure how CI keeps working.
> > 
> > The way I view it, if you are on an old system, then stick to old DPDK
> > LTS version.
> > We don't want to here about regressions on end of life systems.  
> 
> The system requirements in the Getting Started Guide [1] says:
> 
> Kernel version >= 4.14
> The kernel version required is based on the oldest long term stable kernel available at kernel.org when the DPDK version is in development.
> Compatibility for recent distribution kernels will be kept, notably RHEL/CentOS 7.

We need to drop CentOS 7 soon.

https://www.redhat.com/en/topics/linux/centos-linux-eol

	CentOS Linux 7 will reach end of life (EOL) on June 30, 2024.