43 NUMA-aware scheduling #

Non-Uniform Memory Access or Non-Uniform Memory Architecture (NUMA) is a physical memory design used in SMP (multiprocessors) architecture, where the memory access time depends on the memory location relative to a processor. Under NUMA, a processor can access its own local memory faster than non-local memory, that is, memory local to another processor or memory shared between processors.

43.1 Identifying NUMA nodes #

 

To identify the NUMA nodes, on your system use the following command:

$ lscpu | grep NUMA
NUMA node(s):                       1
NUMA node0 CPU(s):                  0-63

Note

For this example, we have only one NUMA node showing 64 CPUs.

NUMA needs to be enabled in the BIOS. If dmesg does not have records of NUMA initialization during the bootup, then NUMA-related messages in the kernel ring buffer might have been overwritten.