From a0893edf184aa760236e30e08f0e40154bb405c6 Mon Sep 17 00:00:00 2001
From: Franck Cuny <franck@fcuny.net>
Date: Sun, 19 Jun 2022 14:53:12 -0700
Subject: 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>
---
 tools/numap/numa.go | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 tools/numap/numa.go

(limited to 'tools/numap/numa.go')

diff --git a/tools/numap/numa.go b/tools/numap/numa.go
new file mode 100644
index 0000000..402ea1d
--- /dev/null
+++ b/tools/numap/numa.go
@@ -0,0 +1,116 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"golang.fcuny.net/numap/internal/hwids"
+	"golang.fcuny.net/numap/internal/sysfs"
+)
+
+const (
+	node_root      = "/sys/devices/system/node/node*"
+	CLASS_NVMe     = 67586
+	CLASS_ETHERNET = 131072
+	CLASS_GPU      = 197120
+)
+
+type node struct {
+	Name       string      `json:"name"`
+	Path       string      `json:"path"`
+	CpuList    string      `json:"cpulist"`
+	PCIDevices []PCIDevice `json:"pci_devices"`
+}
+
+type PCIDevice struct {
+	Vendor string `json:"vendor"`
+	Name   string `json:"name"`
+}
+
+func findNodes(hwdb hwids.PciDevices) (map[string]node, error) {
+	nodes := make(map[string]node)
+
+	files, err := filepath.Glob(node_root)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to find NUMA nodes under %s: %+v", node_root, err)
+	}
+	if len(files) == 0 {
+		return nil, fmt.Errorf("Could not find NUMA node in %s", node_root)
+	}
+
+	for _, f := range files {
+		n, err := newNode(f)
+		if err != nil {
+			return make(map[string]node), err
+		}
+		nodes[n.Name] = n
+	}
+
+	r, err := mapPCIDevicesToNumaNode(hwdb)
+	if err != nil {
+		panic(err)
+	}
+	for k, v := range r {
+		nodeName := fmt.Sprintf("node%d", k)
+		n := nodes[nodeName]
+		n.PCIDevices = v
+		nodes[nodeName] = n
+	}
+	return nodes, nil
+}
+
+func mapPCIDevicesToNumaNode(hwdb hwids.PciDevices) (map[int][]PCIDevice, error) {
+	devices := sysfs.ScanPCIDevices()
+	r := map[int][]PCIDevice{}
+
+	for _, d := range devices {
+		if d.Class == CLASS_NVMe || d.Class == CLASS_ETHERNET || d.Class == CLASS_GPU {
+			_, ok := hwdb[uint16(d.Vendor)]
+			if ok {
+				desc := hwdb[uint16(d.Vendor)]
+				var vendor, name string
+				for _, m := range desc {
+					if uint64(m.Device) == d.Device && uint64(m.Vendor) == d.Vendor {
+						vendor = m.VendorName
+						name = m.DeviceName
+						break
+					}
+				}
+				pciDevice := PCIDevice{
+					Vendor: vendor,
+					Name:   name,
+				}
+				r[d.NumaNode] = append(r[d.NumaNode], pciDevice)
+			}
+		}
+	}
+	return r, nil
+}
+
+func newNode(p string) (node, error) {
+	_, name := path.Split(p)
+
+	cpulist, err := cpuList(p)
+	if err != nil {
+		return node{}, err
+	}
+
+	return node{
+		Name:       name,
+		Path:       p,
+		CpuList:    cpulist,
+		PCIDevices: []PCIDevice{},
+	}, nil
+}
+
+func cpuList(p string) (string, error) {
+	lpath := filepath.Join(p, "cpulist")
+	c, err := ioutil.ReadFile(lpath)
+	if err != nil {
+		return "", fmt.Errorf("Failed to open %s: %+v", lpath, err)
+	}
+	return strings.TrimRight(string(c), "\n"), nil
+}
-- 
cgit 1.4.1