>Instead of asking the runtime for memory object-by-object, an Arena lets you allocate a large pool of memory upfront. You fill that pool with objects using a simple bump pointer (which is CPU cache-friendly), and when you are done, you free the entire pool at once

>They have been trying to prove they can achieve Arena-like benefits with, for example, improved GC algorithms, but all have failed to land

The new Green Tea GC from Go 1.25 [0]:

  Instead of scanning objects we scan whole pages. Instead of tracking objects on our work list, we track whole pages. We still need to mark objects at the end of the day, but we’ll track marked objects locally to each page, rather than across the whole heap.

[0] https://go.dev/blog/greenteagc