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

On Fri Sep 4, 2026 at 10:24 AM PDT, Steven Rostedt wrote:

On Fri, 4 Sep 2026 12:31:08 -0400
Steven Rostedt [off-list ref] wrote:

quoted

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.