Enable YJIT by default if running Ruby 3.3+ #49947
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There was many public reports of 15-25% latency improvements for Rails apps that did enable Ruby 3.2 YJIT, and in 3.3 it's even better. Following ruby/ruby#8705, in Ruby 3.3 YJIT is paused instead of disabled by default, allowing us to enable it from an initializer.
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| # Automatically enable YJIT as of Ruby 3.3, as it bring very | |||
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@byroot I could be missing something, but this file and the next look identical to me. Do you only need one of them?
(If you only need one, the other one has a better comment so I vote that one.)
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🤦 I messed up. Wanted to mv, but ended up cp...
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@casperisfine just one question regarding the ordering of initializers. I am not very familiar with rails. Ideally YJIT should be enabled last, after all the other initializers have run. Is this the case here? |
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It's not "last last" but close enough. The overwhelming majority of the boot sequence is done at this point. |
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We can try to push it a bit further, but it's tricky. I want to introduce some other callback for other reasons, if that happens I may use them to enable YJIT even later. |
There was many public reports of 15-25% latency improvements for Rails apps that did enable Ruby 3.2 YJIT, and in 3.3 it's even better.
Following ruby/ruby#8705, in Ruby 3.3 YJIT is paused instead of disabled by default, allowing us to enable it from an initializer.
FYI: @maximecb, @k0kubun, @XrXr