On March 28, 2012 04:41:16 Simon Marlow wrote:
Sure. Do you have a NUMA machine to test on?
My understanding is non-NUMA machines went away when the AMD and Intel moved away from frontside buses (FSB) and integrated the memory controllers on die. Intel is more recent to this game. I believe AMD's last non-NUMA machines where the Athalon XP series and Intel's the Core 2 series. An easy way to see what you've got is to see what 'numactl --hardware' says. If the node distance matrix is not uniform, you have NUMA hardware. As an example, on a 8 socket Opteron machine (32 cores) you get $ numactl --hardware available: 8 nodes (0-7) node 0 size: 16140 MB node 0 free: 3670 MB node 1 size: 16160 MB node 1 free: 3472 MB node 2 size: 16160 MB node 2 free: 4749 MB node 3 size: 16160 MB node 3 free: 4542 MB node 4 size: 16160 MB node 4 free: 3110 MB node 5 size: 16160 MB node 5 free: 1963 MB node 6 size: 16160 MB node 6 free: 1715 MB node 7 size: 16160 MB node 7 free: 2862 MB node distances: node 0 1 2 3 4 5 6 7 0: 10 20 20 20 20 20 20 20 1: 20 10 20 20 20 20 20 20 2: 20 20 10 20 20 20 20 20 3: 20 20 20 10 20 20 20 20 4: 20 20 20 20 10 20 20 20 5: 20 20 20 20 20 10 20 20 6: 20 20 20 20 20 20 10 20 7: 20 20 20 20 20 20 20 10 On our more traditional NUMA there are 64 nodes and the numbers range from 10-37. But it's an older SGI Itanium solution, so that comes with its own set of problems, and most modern machines are already out performing it. Cheers! -Tyson