10-20% performance regression between 5.9 and 5.10

[davidtaylorhq]

🐞 Describe the Bug

emberperf (https://emberperf.discourse.org/, https://github.com/discourse/ember-performance) has identified a performance regression between Ember 5.9 and 5.10. This is in addition to the earlier (and more significant) glimmer-vm regression being tracked in glimmerjs/glimmer-vm#1590.

Running against individual commits between 5.9 and 5.10 shows:

This suggests that the performance regression was introduced in 53b2de8 (cc @ef4)

🔬 Minimal Reproduction

Released ember versions can be tested at https://emberperf.discourse.org/. Enable the "Render Complex List (Glimmer)" test, and choose Ember versions to test.

The version of emberperf with per-commit tests can be found at discourse/ember-performance#7

[ef4]

I'll take a look.

(My first impression of the benchmarking suite: it sure is tied to the non-ES-modules way of doing things that we're trying to deprecate.)

[NullVoxPopuli]

This should resolve

• [BUGFIX beta] Upgrade glimmer-vm for some perf improvements #20746