Rename cuda::experimental::managed_memory_resource to cuda::experimental::unified_memory_resource

[brycelelbach]

"Managed memory" is a terrible and unclear name for the CUDA Unified Memory feature, and it may be particularly confusing to C++ users, as there is an existing, deprecated, and terrible thing called "Managed C++".

C++ people don't like things that are "managed"; people write C++ because they want control. This name makes Unified Memory sound like a scary black box with perf issues. Couple that with the fact that historically Unified Memory has had perf issues, and the name sounds the wrong sort of message.

We can't rename cudaMallocManaged, but we don't have to repeat the mistake. Please call it cudax::experimental::unified_memory_resource not cudax::experimental::managed_memory_resource.

[brycelelbach]

@jrhemstad @ericniebler Who is the right person to see this?

[miscco]

We can happily rename it

[bdice]

The lack of clarity in naming here comes up often for RMM users. Docs should mention both names with any technical details about how they differ. I believe there are some subtleties that we should make sure we understand and can teach users before renaming this.

[brycelelbach]

CCCL docs should definitely mention all terms in use: Unified Memory, UVM, Managed Memory.

Somewhere we should also explain HMM/ATS. We need an explainer for this whole feature somewhere. Blog post maybe.

[brycelelbach]

I would also be fine with exposing multiple names via aliases.

[miscco]

In the PR I am linking to https://developer.nvidia.com/blog/unified-memory-cuda-beginners/

Any other blogs that would make sense?