CXL Support Continues To Be Refined In Linux 5.19 Ahead Of Next-Gen Servers

Intel has been working heavily on getting the Compute Express Link (CXL) subsystem in place so that when next-generation servers appear with this new high-speed interconnect industry standard, open-source operating systems will be ready.

Each kernel cycle we've been seeing more CXL enablement work piling up in the kernel and that is still certainly the case with the new Linux 5.19 cycle. Linux 5.19 is readying CXL "_OSC" support for claiming native control of CXL device hot-plug and error handling, disabling system suspend support in the presence of CXL memory until there is the ability to restore PCI device contexts from memory on CXL PCI devices, support for snooping CXL mailbox commands to protect against inopportune changes, preparations for new CXL 2.0 decode configurations, and various other fix-ups / cleanups / additions.

The full list of Compute Express Link changes for Linux 5.19 via this pull that was mainlined last night.

Meanwhile Intel engineer Ben Widawsky has begun publishing a blog post series around CXL on Linux for those interested in this tech that is going to play a big role in next-gen, HPC servers.