Function GetMachineMemoryByType

lib/machine/machine.go:194–241

GetMachineMemoryByType returns information about memory capacity and number of DIMMs. Information is retrieved from sysfs edac per-DIMM API (/sys/devices/system/edac/mc/) introduced in kernel 3.6. Documentation can be found at https://www.kernel.org/doc/Documentation/admin-guide/ras.rst. Full list o

(edacPath string)

// Full list of memory types can be found in edac_mc.c
// (https://github.com/torvalds/linux/blob/v5.5/drivers/edac/edac_mc.c#L198)
func GetMachineMemoryByType(edacPath string) (map[string]*info.MemoryInfo, error) {
	memory := map[string]*info.MemoryInfo{}
	names, err := os.ReadDir(edacPath)
	// On some architectures (such as ARM) memory controller device may not exist.
	// If this is the case then we ignore error and return empty slice.
	_, ok := err.(*os.PathError)
	if err != nil && ok {
		return memory, nil
	} else if err != nil {
		return memory, err
	}
	for _, controllerDir := range names {
		controller := controllerDir.Name()
		if !isMemoryController.MatchString(controller) {
			continue
		}
		dimms, err := os.ReadDir(path.Join(edacPath, controllerDir.Name()))
		if err != nil {
			return map[string]*info.MemoryInfo{}, err
		}
		for _, dimmDir := range dimms {
			dimm := dimmDir.Name()
			if !isDimm.MatchString(dimm) {
				continue
			}
			memType, err := os.ReadFile(path.Join(edacPath, controller, dimm, memTypeFileName))
			if err != nil {
				return map[string]*info.MemoryInfo{}, err
			}
			readableMemType := strings.TrimSpace(string(memType))
			if _, exists := memory[readableMemType]; !exists {
				memory[readableMemType] = &info.MemoryInfo{}
			}
			size, err := os.ReadFile(path.Join(edacPath, controller, dimm, sizeFileName))
			if err != nil {
				return map[string]*info.MemoryInfo{}, err
			}
			capacity, err := strconv.Atoi(strings.TrimSpace(string(size)))
			if err != nil {
				return map[string]*info.MemoryInfo{}, err
			}
			memory[readableMemType].Capacity += uint64(mbToBytes(capacity))
			memory[readableMemType].DimmCount++
		}
	}

	return memory, nil
}

func mbToBytes(megabytes int) int {
	return megabytes * 1024 * 1024