NUMA emulation

If CONFIG_NUMA_EMU is enabled, you can create fake NUMA nodes with numa=fake= kernel cmdline option. See The kernel’s command-line parameters and Fake NUMA For CPUSets for more information.

Multiple Memory Tiers Creation

The “numa_emulation.adistance=” kernel cmdline option allows you to set the abstract distance for each NUMA node.

For example, you can create two fake nodes, each in a different memory tier by booting with “numa=fake=2 numa_emulation.adistance=576,704”. Here, the abstract distances of node0 and node1 are set to 576 and 706, respectively.

Each memory tier covers an abstract distance chunk size of 128. Thus, nodes with abstract distances between 512 and 639 are classified into the same memory tier, and nodes with abstract distances between 640 and 767 are classified into the next slower memory tier.

The abstract distance of fake nodes not specified in the parameter will be the default DRAM abstract distance of 576.