The minimum distance is defined to be 10 and all the zones are equally close.But to my big surprise the Pi5 reports 8 numa nodes?!?!?8 numa nodes with 512MB for my 4GB Pi5 ...pi@raspberrypi5:~ $ numactl -H
available: 8 nodes (0-7)
node 0 cpus: 0 1 2 3
node 0 size: 487 MB
node 0 free: 100 MB
node 1 cpus: 0 1 2 3
node 1 size: 501 MB
node 1 free: 107 MB
node 2 cpus: 0 1 2 3
node 2 size: 509 MB
node 2 free: 132 MB
node 3 cpus: 0 1 2 3
node 3 size: 509 MB
node 3 free: 120 MB
node 4 cpus: 0 1 2 3
node 4 size: 509 MB
node 4 free: 131 MB
node 5 cpus: 0 1 2 3
node 5 size: 509 MB
node 5 free: 83 MB
node 6 cpus: 0 1 2 3
node 6 size: 509 MB
node 6 free: 115 MB
node 7 cpus: 0 1 2 3
node 7 size: 507 MB
node 7 free: 172 MB
node distances:
node 0 1 2 3 4 5 6 7
0: 10 10 10 10 10 10 10 10
1: 10 10 10 10 10 10 10 10
2: 10 10 10 10 10 10 10 10
3: 10 10 10 10 10 10 10 10
4: 10 10 10 10 10 10 10 10
5: 10 10 10 10 10 10 10 10
6: 10 10 10 10 10 10 10 10
7: 10 10 10 10 10 10 10 10
pi@raspberrypi5:~ $
I think the output is the result of those fake NUMA patches discussed in
viewtopic.php?t=378276
My understanding is the code used to interleave memory across NUMA zones can also be used to spread active pages across different banks.
Statistics: Posted by ejolson — Tue Aug 26, 2025 10:43 pm