Re: bpf-next experiment

[Simon Horman <horms@kernel.org>]

On Wed, Aug 14, 2024 at 12:32:00PM -0700, Alexei Starovoitov wrote:
> Hi All,
> 
> Couple years ago folks suggested that bpf-next should be
> a separate pull request to increase subsystem visibility.
> Back then we rejected the idea since many networking related
> changes required bpf core changes. Things are different now.
> bpf kfuncs can be added independently by various subsystems,
> verifier additions are mainly driven by sched-ext,
> so it's time to give it a shot. It's an experiment.
> If things don't work out as expected we will go back to
> the old model of feeding bpf trees through net/net-next trees.
> 
> So here is the plan:
> 
> 1. bpf fixes go directly to Linus (skipping net tree) and
> net/bpf trees are fast forwarded afterwards as usual.
> 
> 2. Non-networking bpf commits land in bpf-next/master branch.
> It will form bpf-next PR during the merge window.
> 
> 3. Networking related commits (like XDP) land in bpf-next/net branch.
> They will be PR-ed to net-next and ffwded from net-next
> as we do today. All these patches will get to mainline
> via net-next PR.

Hi Alexei,

Nice plan :)

I wonder if, bpf-next/net-next might be a more intuitive name, as the
proposed branch is closely related to net-next.

OTOH, mabey one '-next', as per your proposal, is enough :)

> 
> 4. bpf-next/master and bpf-next/net branches are manually
> merged into bpf-next/for-next branch.
> This step achieves two objectives:
> - bpf maintainers watch for conflicts between /master and /net
> - Stephen Rothwell continues taking /for-next branch into linux-next
> as usual
> 
> bpf CI will run tests against 4 trees (instead of 2):
> bpf, bpf-next/master, bpf-next/net, bpf-next/for-next.
> This is wip. Watch for more "Checks" in patchwork.
> 
> By the merge window in September we will reassess
> the situation and if it's still worth doing we will
> proceed with PR formed from bpf-next/master.
> If not, we will PR bpf-next/master into net-next and
> call it a failed experiment.
> 
> We feel that there are more positives to this process
> than headaches, so fingers crossed.
>