[hinkley]

Slab allocators don’t provide real time guarantees. That is arena allocators. The distinction may seem trivial but the requirements are distinct.

In tiny systems all allocations of one type may come from a single operation, but in larger systems what fits in a slab will come from distinct concerns with different priorities. You want a different arena for those allocations.

[widdershins]

I'm confused. To me it seems that real time guarantees are a function of three things:

- Is it constant time in algorithmic complexity?

- Is it single threaded (i.e. free from locks)?

- Does it need to fetch memory from the system (not realtime safe)?

There are slab allocators that can satisfy all of these, and are therefore realtime safe.

So I'm still wondering what the difference is.