65 lines
1.4 KiB
Go
65 lines
1.4 KiB
Go
// +build linux
|
|
|
|
package sys
|
|
|
|
import (
|
|
"bufio"
|
|
"fmt"
|
|
"os"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"github.com/opencontainers/runc/libcontainer/system"
|
|
)
|
|
|
|
const nanoSecondsPerSecond = 1e9
|
|
|
|
var clockTicksPerSecond = uint64(system.GetClockTicks())
|
|
|
|
// GetSystemCPUUsage returns the host system's cpu usage in
|
|
// nanoseconds. An error is returned if the format of the underlying
|
|
// file does not match.
|
|
//
|
|
// Uses /proc/stat defined by POSIX. Looks for the cpu
|
|
// statistics line and then sums up the first seven fields
|
|
// provided. See `man 5 proc` for details on specific field
|
|
// information.
|
|
func GetSystemCPUUsage() (uint64, error) {
|
|
var line string
|
|
f, err := os.Open("/proc/stat")
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
bufReader := bufio.NewReaderSize(nil, 128)
|
|
defer func() {
|
|
bufReader.Reset(nil)
|
|
f.Close()
|
|
}()
|
|
bufReader.Reset(f)
|
|
err = nil
|
|
for err == nil {
|
|
line, err = bufReader.ReadString('\n')
|
|
if err != nil {
|
|
break
|
|
}
|
|
parts := strings.Fields(line)
|
|
switch parts[0] {
|
|
case "cpu":
|
|
if len(parts) < 8 {
|
|
return 0, fmt.Errorf("bad format of cpu stats")
|
|
}
|
|
var totalClockTicks uint64
|
|
for _, i := range parts[1:8] {
|
|
v, err := strconv.ParseUint(i, 10, 64)
|
|
if err != nil {
|
|
return 0, fmt.Errorf("error parsing cpu stats")
|
|
}
|
|
totalClockTicks += v
|
|
}
|
|
return (totalClockTicks * nanoSecondsPerSecond) /
|
|
clockTicksPerSecond, nil
|
|
}
|
|
}
|
|
return 0, fmt.Errorf("bad stats format")
|
|
}
|