feat(tools/numap): add a tool to report NUMA topology of a host

The tool maps the various PCI devices to the NUMA node they are attached
to and print the result to STDOUT in JSON.

Only ethernet, NVMe and GPU devices are accounted for at the moment.

Change-Id: If32c805e61211f0ef4838a82eabc70d7fc1985fe
Reviewed-on: https://cl.fcuny.net/c/world/+/453
Tested-by: CI
Reviewed-by: Franck Cuny <franck@fcuny.net>

1 files changed, 48 insertions, 0 deletions

diff --git a/tools/numap/README.org b/tools/numap/README.org
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+#+TITLE: numap
+
+Print the NUMA topology of a host.
+
+* Usage
+#+BEGIN_SRC sh
+./numap |jq .
+{
+  "node0": {
+    "name": "node0",
+    "path": "/sys/devices/system/node/node0",
+    "cpulist": "0-19,40-59",
+    "pci_devices": [
+      {
+        "vendor": "Mellanox Technologies",
+        "name": "MT27710 Family [ConnectX-4 Lx]"
+      },
+      {
+        "vendor": "Mellanox Technologies",
+        "name": "MT27710 Family [ConnectX-4 Lx]"
+      }
+    ]
+  },
+  "node1": {
+    "name": "node1",
+    "path": "/sys/devices/system/node/node1",
+    "cpulist": "20-39,60-79",
+    "pci_devices": [
+      {
+        "vendor": "Intel Corporation",
+        "name": "NVMe Datacenter SSD [3DNAND, Beta Rock Controller]"
+      }
+    ]
+  }
+}
+#+END_SRC
+
+The command will scan the host to find the NUMA nodes, and all the PCI devices, and map the PCI devices back to the NUMA node.
+
+It also provides a way to see the list of CPUs attached to the node.
+
+* Limitations
+** Device class
+For now only the following classes of hardware are cared for:
+- NVMe
+- network
+- GPU
+