Intel Cache Allocation Technology / RDT Still Baking For Linux

Not mentioned in my earlier features you won't find in the Linux 4.9 mainline kernel is support for Intel's Cache Allocation Technology (CAT) but at least it was revised this weekend in still working towards mainline integration.

Cache Allocation Technology is about letting an OS/VMM restrict cache allocation to a defined subset of cache. Making use of Cache Allocation Technology can allow for more cache to be available for higher priority applications and the defined CAT subsets can be dynamically changed. Intel has been working on Cache Allocation Technology for Linux going back to 2014.

The fifth version of these CAT patches were published on Saturday. It appears CAT requires Haswell CPUs and newer. Adding this code to the kernel is just over two thousand lines of new code. The work involves adding a "resctrl" (resource control) file-system derived from kernfs and the new functionality is exposed via the CONFIG_INTEL_RDT_A Kconfig switch, short for the Intel Resource Director Technology Allocation support, with the functionality being provided by the new intel_rdt driver. More details via the Linux kernel mailing list. Documentation on the user-space interface via this patch.