Good for didactic purposes but in the real world you may want to try an allocator like tcmalloc or jemalloc.
The simplest case is if you know that you will free everything at once, or nothing at all. This allows you to eliminate most bookkeeping and allows a completely lock-free architecture. But there are also more complex cases where you can still get big benefits from exploiting known invariants.
jemalloc allows you to query these invariants if you don't know them, and to use the information to re-configure the allocator to match them :/
I'm pretty sure most modern allocators allow you to do this as well.
> The simplest case is if you know that you will free everything at once, or nothing at all.
That's pretty much a one liner with jemalloc.
With real time requirements you often care about your response time or worst case execution time. In some areas of embedded, safety critical systems you're usually prohibited from using heap at all (instead, stuff is put in global variables or on the stack - so you're only growing in one direction).