Linux 5.1 Might Pick Up Support For Using Persistent Memory As System RAM

While we are expecting to see more Intel Optane NVDIMMs this year that offer up persistent memory using 3DXPoint memory on the DDR4 bus for persistent storage, the Linux 5.1 kernel might pick-up support for treating this persistent memory back as traditional RAM if so desired.

Intel Optane DC Persistent Memory is expected to begin appearing in more servers this year for offering application-level persistent memory for use-cases like database servers, HPC, and other enterprise computing possibilities. If you are buying such NVDIMMs in the first place, chances are you planning to utilize the persistent memory for such purposes, but otherwise with Linux 5.1 there are patches pending to allow this PMEM to function as traditional system RAM.

Device-DAX code updates queued for Linux 5.1 allow for persistent memory and other reserved/differentiated memory to be assigned to the core memory management code as system memory. This will treat the NVDIMMs as volatile RAM and support all of the traditional Linux memory management interfaces.

More details on this pending work via this patch series. While it's a pull request to land in Linux 5.1, Linus Torvalds has requested clarification about some behavior from Intel and is awaiting that before he considers merging the code.