Re: [PATCH bpf-next v3 00/17] mm: BPF OOM

[Matt Bobrowski]

On Wed, Jan 28, 2026 at 08:59:34AM -0800, Alexei Starovoitov wrote:
> On Wed, Jan 28, 2026 at 12:06 AM Michal Hocko <mhocko@xxxxxxxx> wrote:
> >
> >
> > > Another viable idea (also suggested by Andrew Morton) is to develop
> > > a production ready memcg-aware OOM killer in BPF, put the source code
> > > into the kernel tree and make it loadable by default (obviously under a
> > > config option). Myself or one of my colleagues will try to explore it a
> > > bit later: the tricky part is this by-default loading because there are
> > > no existing precedents.
> >
> > It certainly makes sense to have trusted implementation of a commonly
> > requested oom policy that we couldn't implement due to specific nature
> > that doesn't really apply to many users. And have that in the tree. I am
> > not thrilled about auto-loading because this could be easily done by a
> > simple tooling.
> 
> Production ready bpf-oom program(s) must be part of this set.
> We've seen enough attempts to add bpf st_ops in various parts of
> the kernel without providing realistic bpf progs that will drive
> those hooks. It's great to have flexibility and people need
> to have a freedom to develop their own bpf-oom policy, but
> the author of the patch set who's advocating for the new
> bpf hooks must provide their real production progs and
> share their real use case with the community.
> It's not cool to hide it.
> In that sense enabling auto-loading without requiring an end user
> to install the toolchain and build bpf programs/rust/whatnot
> is necessary too.
> bpf-oom can be a self contained part of vmlinux binary.
> We already have a mechanism to do that.
> This way the end user doesn't need to be a bpf expert, doesn't need
> to install clang, build the tools, etc.
> They can just enable fancy new bpf-oom policy and see whether
> it's helping their apps or not while knowing nothing about bpf.

For the auto-loading capability you speak of here, I'm currently
interpreting it as being some form of conceptually similar extension
to the BPF preload functionality. Have I understood this correctly? If
so, I feel as though something like this would be a completely
independent stream of work, orthogonal to this BPF OOM feature, right?
Or, is that you'd like this new auto-loading capability completed as a
hard prerequisite before pulling in the BPF OOM feature?