PROBLEM: If the NUMA nodes in a system are not contiguous, numactl shows incorrect output. Here is an example from one such system: ------------------------------------------------------ # ls /sys/devices/system/node has_cpu has_normal_memory node0 node1 node4 node5 online possible # numactl --hardware available: 6 nodes (0-5) node 0 cpus: 0 1 2 3 node 0 size: 15232 MB node 0 free: 2265 MB node 1 cpus: 4 5 6 7 node 1 size: 16256 MB node 1 free: 3108 MB libnuma: Warning: /sys not mounted or invalid. Assuming one node: No such file or directory node 2 cpus: node 2 size: <not available> node 2 free: <not available> node 3 cpus: node 3 size: <not available> node 3 free: <not available> node 4 cpus: 8 9 10 11 node 4 size: 16000 MB node 4 free: 9292 MB node 5 cpus: 12 13 14 15 node 5 size: 16128 MB node 5 free: 9479 MB node distances: node 0 1 2 3 4 5 0: 10 20 20 20 20 10 1: 20 10 20 20 0 0 2: 0 0 0 0 0 0 3: 0 0 0 0 0 0 4: 0 0 0 1112145 1024 2607344 5: 1024 2607344 1024 2607344 0 0 ------------------------------------------------------ As we see above, there are three problems with above output: o it is showing wrong number of available nodes Actually there are 4 nodes available, but it says "6". o it tries to access information for non-exsistent nodes from /sys Thus displaying a wrong warning message too o the NUMA distances it shows above are clearly incorrect. Following two patches fixes these problems: 1) numactl-handle-NUMA-dist-properly.patch 2) numactl-ignore-nonavailable-nodes.patch -- Regards, Amit Arora -- To unsubscribe from this list: send the line "unsubscribe linux-numa" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
