The Green Tea Garbage Collector
6 months ago
- #Garbage collection
- #Performance optimization
- #Go programming
- Go 1.25 introduces an experimental garbage collector called Green Tea, which reduces GC time by 10-40% for many workloads.
- Green Tea is production-ready and used at Google, with plans to make it default in Go 1.26.
- The traditional Go garbage collector uses a mark-sweep algorithm, which involves marking reachable objects and sweeping unreachable ones.
- Green Tea optimizes GC by working with memory pages instead of individual objects, improving cache utilization and reducing memory stalls.
- Vector hardware acceleration (e.g., AVX-512) further enhances Green Tea's performance by enabling efficient page-wide operations.
- Early benchmarks show 10-40% reduction in GC CPU costs, with additional improvements expected from vector acceleration.
- Green Tea is available in Go 1.25 via GOEXPERIMENT=greenteagc, with opt-out possible in Go 1.26 using GOEXPERIMENT=nogreenteagc.
- Feedback from users is encouraged to refine and improve Green Tea before its full release.