Tcmalloc of 5 years ago is very very different from the standalone one released in the past couple of years. Both versions also have a lot of knobs to tune the overhead (the latest one being much better about giving memory back). Still, tcmalloc’s heritage is large servers running in the cloud. Mimalloc may make different trade offs and Google uses Scudo on Android instead of jemalloc (LLVMs hardened allocator sharing some of the ideas of tcmalloc).