Whistler: Live eBPF Programming from the Common Lisp REPL | Hacker News Reader

Whistler: Live eBPF Programming from the Common Lisp REPL

atgreen.github.io

134 pointsvarjag18 comments

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Just recently discovered the author, Anthony Green. Floored and inspired by his productivity and scope of projects!

I enjoyed reading up on his fiber implementation and dabbling with the Java compiler/runtime integration.

https://atgreen.github.io/repl-yell/posts/sbcl-fibers/

https://github.com/atgreen/openldk

Kudos Anthony - you make the world a more interesting place ;-)

Thank you!

This is very cool.

I'm in danger of being nerd sniped.

Very impressive, good reason to get into Lisp, I reckon

While this is an interesting project, I found following grating:

"Permissions without root

You don’t need root. Grant capabilities to SBCL:

sudo setcap cap_bpf,cap_perfmon+ep /usr/bin/sbcl

Now sbcl --load my-bpf-program.lisp works as your regular user. Tracepoint format files need chmod a+r to allow non-root compilation with deftracepoint."

That's obviously not ideal. Better might be to create a purpose-built image. Unlike perl, sbcl doesn't even pretend to care about security. Taint mode extension for sbcl, anybody?

> Unlike perl, sbcl doesn't even pretend to care about security.

Mind expanding? What particular stuff does Perl have in terms of security here?

A lot, to the point where there's an entire security page in perldoc: <https://perldoc.perl.org/perlsec>

I wonder if a taint mode for SBCL would mean ignoring SBCL_HOME... that'd be a bit annoying for running more up-to-date SBCL versions on distros shipping with older versions.

very cool and the person has the skills to do that. sad to see how the fully AI generated "why this matters" section in the blog gives a lingering vibe of slop.

> sad to see how the fully AI generated "why this matters" section in the blog gives a lingering vibe of slop.

I am quoting this verbatim from offending section:

Why this matters

The traditional eBPF workflow is: write C for the BPF side, compile with clang, then write Go or Rust or Python for the userspace side. Two languages, separate build steps, multiple processes.

With Whistler 1.0, the workflow is: write Lisp. The compiler, loader, and userspace application share a process. You can develop at the REPL — modify a probe, re-eval the form, see results immediately. The feedback loop is instant.

Seems like a reasonable paragraph. I sincerely feel we must stop tainting things with the "slop" pejorative unless it really seems egregious. Also in 2026 is it easy to be so confident about what was generated by a human, edited by a human or generated by an LLM ?

My main metric is: does the paragraph add value ? It does to me as a summary.

The author has been using AI for other Lisp projects.

Yes, but it seems to me like atgreen takes care to ensure the result is decent, so I would hesitate before calling it slop. I may be wrong, though.

He's been also doing Lisp projects before GenAI, so…

That dude just wanted everyone to know that he found the emdash, that he is so vigorously looking for in everything he reads these days.

It's more the repeated 'rule of three' that's getting me here.

That said, this is a relatively tame tack-on to a very meaty post, not worth harping on unless the project itself has similar issues.

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