I'm definitely sympathetic to the argument that by avoiding allocation in the first place that you don't have to worry as much about memory profile. I allocate

I'm definitely sympathetic to the argument that by avoiding allocation in the first place that you don't have to worry as much about memory profile. I allocate and destroy a bunch of arrays in my code (~100MB every minute), so it's not huge but definitely quite a few pages every time it happens. And so far I've got one process that's been running for 6 months. For the most part, whenever I get new data, I take a slice of an old array and append the new data to it to create a new array. It's fast enough, but more importantly it's just so much easier to do it that way and with a compacting GC I don't have to worry about anything. Of course I don't know how good jemalloc is at avoiding fragmentation, and I don't have the time to rewrite my code (maybe enough time to simulate, not sure). But my code creates a ton of fragment-y garbage, and I would imagine that with Rust I would end up not just translating my code, but changing semantics to mutate in place, just to avoid fragmentation. I guess maybe /r/rust would be the place to ask.