Merge pull request #631 from bastelfreak/openvox9

document YJIT / ZJIT for openvox 9

Author: corporate-gadfly

_posts/2026-02-26-road-to-openvox-9.md

@@ -21,6 +21,71 @@ Although we still have many outstanding changes, we tackled some milestones. We
 * Removed curl from the agent package
 * Removed multi_json gem
 
-Besides that, the agent is identical to openvox-agent 8.25.0 right now.
+The Ruby build has support for [YJIT](https://docs.ruby-lang.org/en/4.0/jit/yjit_md.html) and [ZJIT](https://docs.ruby-lang.org/en/4.0/jit/zjit_md.html), on some platforms.
+The different just in time compilers might provide a performance benefit.
+Some of their features are still experimental.
+To compile Ruby with it, a modern Rust 1.85.0 is required. We can not build ZJIT on the following platforms:
+
+* debian-11-aarch64
+* debian-11-amd64
+* debian-12-aarch64
+* debian-12-amd64
+* debian-13-armhf
+* macos-all-arm64
+* macos-all-x86_64
+* sles-15-x86_64
+* sles-16-aarch64
+* sles-16-x86_64
+* ubuntu-22.04-aarch64
+* ubuntu-22.04-amd64
+* ubuntu-24.04-aarch64
+* ubuntu-24.04-amd64
+* ubuntu-24.04-armhf
+* ubuntu-25.04-aarch64
+* ubuntu-25.04-amd64
+* ubuntu-25.04-armhf
+* ubuntu-26.04-armhf
+* windows-all-x64
+
+For YJIT Rust is still required, but 1.58.0 is sufficient.
+We could build YJIT on some platforms where ZJIT doesn't work, but that's not configured right now.
+YJIT is available in Ruby 3.2 as well, so we could enable it for openvox 8.
+
+To test ZJIT / YJIT, you can add the commandline option to Ruby:
+
+```diff
+--- a/opt/puppetlabs/puppet/bin/puppet
++++ a/opt/puppetlabs/puppet/bin/puppet
+@@ -1,4 +1,4 @@
+-#!/opt/puppetlabs/puppet/bin/ruby
++#!/opt/puppetlabs/puppet/bin/ruby --zjit
+ # frozen_string_literal: true
+
+ begin
+```
+
+or:
+
+```diff
+--- a/opt/puppetlabs/puppet/bin/puppet
++++ a/opt/puppetlabs/puppet/bin/puppet
+@@ -1,4 +1,4 @@
+-#!/opt/puppetlabs/puppet/bin/ruby
++#!/opt/puppetlabs/puppet/bin/ruby --zjit
+ # frozen_string_literal: true
+
+ begin
+```
+
+There are a few options, which you can check in `/opt/puppetlabs/puppet/bin/ruby --help` or the documentation for [YJIT](https://docs.ruby-lang.org/en/4.0/jit/yjit_md.html) and [ZJIT](https://docs.ruby-lang.org/en/4.0/jit/zjit_md.html).
+A helpful option is also `--zjit-stats` which will print some profiling data to stdout.
+
+**It's not guaranteed that we will ship either JIT implementations in the stable builds.**
+
+We first need to prove that they don't introduce any performance regressions.
+
+---
+
+Beside those changes, the agent is identical to openvox-agent 8.25.0 right now.
 Please download the packages from [artifacts.voxpupuli.org](https://artifacts.voxpupuli.org/openvox-agent/8.25.0.9.g086d1fd67/) and give us feedback.
 (If you are interested in setting up an actual nightlies/staging rpm/deb repo, that's also highly appreciated).