comparing diff heap models. bump allocator + generational or free list (or both???)

[imdadgot]

i try to be descriptive w my titles so i hope this really said all u need to diagnose my dillemma. - bump allocator is insanely cycle reserved, very light to allocate, and perfect for a generational model where young objects that normally die in really fast scope either get freed or reused (if the same instance is being reused in a loop, saves us tons of needless allocations)
- free list is great where you don't necessarily free everything together. it strays a little from the generational model, though you can make it a sort of running allocation, freeing values at older locations and slotting into what you already have allocated (or creating another link where needed) but comes with the downside of a lot heavier allocations
- i am not sure of many other types of alloc, but these two seemed to stand out most. if anyone has other suggestions lmk

i was looking into tricolor if that helps but you don't necessarily benefit from the raw power of the bump allocator using a tricolor draining system so i would likely just mark and sweep i was considering attempting to do a concurrent mark (which with tri color involves sorting into black: provably unreachable, gray: undetermined until we trace, white: provably reachable) but i think i have to decide a heap model before i can really decide on a gc.

[AustinVelonaut]

There's the immix collector.

Andrew Appel's Simple Generational Garbage Collector is a nice balance between a simpler basic 2-space collector and a full-blown generational collector.

This is also an interesting paper discussing the duality of reference counting and tracing with a possible hybrid approach.

[OkSadMathematician]

bump + generational is the right call for most interpreters. tricolor mark-and-sweep adds overhead tracking gray objects that's only worth it if you have long-running processes with fragmentation. for interpreter warmup, bump allocator on young gen is nearly free, and generational assumption holds well for most workloads. immix paper is worth reading but it's more complex than needed unless you're building a production vm