The Green Tea Garbage Collector
Key topics
The Go team has introduced a new garbage collector called the 'Green Tea Garbage Collector', which improves upon the existing GC algorithm, sparking discussion and praise from the community for its technical explanation and innovative approach.
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Day 1
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- 01Story posted
Oct 29, 2025 at 1:03 PM EDT
2 months ago
Step 01 - 02First comment
Oct 29, 2025 at 3:01 PM EDT
2h after posting
Step 02 - 03Peak activity
27 comments in Day 1
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Step 03 - 04Latest activity
Nov 12, 2025 at 11:37 PM EST
about 2 months ago
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[0] https://www.reddit.com/r/golang/comments/1c9fhet/how_much_go...
https://www.more-magic.net/posts/internals-gc.html
I've already been using bitvector SIMD for the sweep portion of mark/sweep. It's neat to see that tracing can be done this way.
VGF2P8AFFINEQB FTW
there's also the inverse: https://www.felixcloutier.com/x86/gf2p8affineinvqb
https://en.wikipedia.org/wiki/Page_%28computer_memory%29
Also FTA: “One surprise result of this work was that scanning a mere 2% of a page at a time can yield improvements over the graph flood.”
⇒ I think you’d have to try and get two objects on each page, and they would have to be small (you’d have to be able to fit over 100 objects in a page to have 2 live objects be <2% of all objects in the page)
All better languages use a modern copying collector, if they have enough memory. It's also compacting, and doesn't stop the world. I think lisps just do mark & sweep on phones or embedded, and the mentioned ffi callbacks.
00: white
10: gray
11: black
then we cam describe it as a very cool variation of the tri-color gc algorithm.
https://en.wikipedia.org/wiki/Tracing_garbage_collection#Tri...