Re: [RFC PATCH 00/20] rv: Add support for BPF monitors

[Alexei Starovoitov]

On Fri Sep 4, 2026 at 10:24 AM PDT, Steven Rostedt wrote:
> On Fri, 4 Sep 2026 12:31:08 -0400
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
>> In the beginning, Daniel Bristot looked into doing this with BPF and found
>> issues with it. I do not recall what they were and unfortunately Daniel is
>> no longer around to explain it. Maybe Gabriele knows what they were.
>
> IIRC, Daniel even told me there was a competing effort within Red Hat to
> implement the same functionality using only BPF. That effort never
> materialized and everything went toward the RV code Daniel was working on.

bpf in 2022 was surely less capable then it is today.
It took us 2 years of bpf core development to statisfy sched-ext demands
and we're still adding new features for sched-ext needs.
If you're trully willing to remove 90% of kernel/trace/rv/ and refactor
it into tiny shim where all of the core pieces are bpf driven we can
certainly work together (like we did with sched-ext) and add whatever
is missing on bpf side. Then all existing monitors will become bpf programs.
But adding bpf as another 'monitor', sorry but hard NO.
If hardcoded monitors was a mistake then admit it and fix it by deleting it,
if it's not a mistake then keep adding hardcoded monitors.