doc/next: add section for Green Tea

Change-Id: I420e8d673e5d34d1b09c02b8bc84b890da42e320
Reviewed-on: https://go-review.googlesource.com/c/go/+/725662
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This commit is contained in:
Michael Anthony Knyszek 2025-12-01 18:07:50 +00:00 committed by Gopher Robot
parent 043b9de658
commit 88c24de8b5

View file

@ -1 +1,22 @@
## Runtime {#runtime}
### New garbage collector
The Green Tea garbage collector, previously available as an experiment in
Go 1.25, is now enabled by default after incorporating feedback.
This garbage collectors design improves the performance of marking and
scanning small objects through better locality and CPU scalability.
Benchmark result vary, but we expect somewhere between a 10—40% reduction
in garbage collection overhead in real-world programs that heavily use the
garbage collector.
Further improvements, on the order of 10% in garbage collection overhead,
are expected when running on newer amd64-based CPU platforms (Intel Ice
Lake or AMD Zen 4 and newer), as the garbage collector now leverages
vector instructions for scanning small objects when possible.
The new garbage collector may be disabled by setting
`GOEXPERIMENT=nogreenteagc` at build time.
This opt-out setting is expected to be removed in Go 1.27.
If you disable the new garbage collector for any reason related to its
performance or behavior, please [file an issue](/issue/new).