[cma]

Hardware support is only very recent, Intel added support at various times and then had to remove it due to security and correctness issues, but I think it is now finally available:

> Intel's Transactional Synchronization Extensions (TSX) is available in some of the Skylake processors. It was earlier implemented in Haswell and Broadwell processors as well, but the implementations turned out both times to be defective and support for TSX was disabled. The TSX specification describes the transactional memory API for use by software developers, but withholds details on technical implementation.[11] ARM architecture has a similar extension.[12]

https://en.wikipedia.org/wiki/Transactional_memory

I believe even with it available, OSes turn it off because of all the other Intel vulnerabilities and it making them even more expensive to workaround.