handle_request top-level function of an HTTP server), this means that instead of going through all of the machinery in tcmalloc you may be performing a dequeue operation on a ring buffer of free frames, substantially faster. Would it be possible to have the coroutine take an alloc: Allocator[CoroutineFrameType] = DefaultMojoAllocator parameter in some way or otherwise inject an allocator into the coroutine? I'm still thinking over how I would want custom allocators to behave, but I know that this a feature I and others will want. 