Add support CpusAllowedList for /proc/[pid]/status (#490)

* add CpusAllowedList for /proc/[pid]/status

Signed-off-by: mn.albeschenko <albeschenko.work@gmail.com>

* Fix documentation comment

Co-authored-by: Ben Kochie <superq@gmail.com>
Signed-off-by: Johannes 'fish' Ziemke <github@5pi.de>

---------

Signed-off-by: mn.albeschenko <albeschenko.work@gmail.com>
Signed-off-by: Johannes 'fish' Ziemke <github@5pi.de>
Co-authored-by: Johannes 'fish' Ziemke <github@5pi.de>
Co-authored-by: Ben Kochie <superq@gmail.com>

proc_status.go

@@ -15,6 +15,7 @@ package procfs
 
 import (
  "bytes"
+ "sort"
  "strconv"
  "strings"
 
@@ -76,6 +77,9 @@ type ProcStatus struct {
  UIDs [4]string
  // GIDs of the process (Real, effective, saved set, and filesystem GIDs)
  GIDs [4]string
+
+ // CpusAllowedList: List of cpu cores processes are allowed to run on.
+ CpusAllowedList []uint64
 }
 
 // NewStatus returns the current status information of the process.
@@ -161,10 +165,38 @@ func (s *ProcStatus) fillStatus(k string, vString string, vUint uint64, vUintByt
  s.VoluntaryCtxtSwitches = vUint
  case "nonvoluntary_ctxt_switches":
  s.NonVoluntaryCtxtSwitches = vUint
+ case "Cpus_allowed_list":
+ s.CpusAllowedList = calcCpusAllowedList(vString)
  }
+
 }
 
 // TotalCtxtSwitches returns the total context switch.
 func (s ProcStatus) TotalCtxtSwitches() uint64 {
  return s.VoluntaryCtxtSwitches + s.NonVoluntaryCtxtSwitches
 }
+
+func calcCpusAllowedList(cpuString string) []uint64 {
+ s := strings.Split(cpuString, ",")
+
+ var g []uint64
+
+ for _, cpu := range s {
+ // parse cpu ranges, example: 1-3=[1,2,3]
+ if l := strings.Split(strings.TrimSpace(cpu), "-"); len(l) > 1 {
+ startCPU, _ := strconv.ParseUint(l[0], 10, 64)
+ endCPU, _ := strconv.ParseUint(l[1], 10, 64)
+
+ for i := startCPU; i <= endCPU; i++ {
+ g = append(g, i)
+ }
+ } else if len(l) == 1 {
+ cpu, _ := strconv.ParseUint(l[0], 10, 64)
+ g = append(g, cpu)
+ }
+
+ }
+
+ sort.Slice(g, func(i, j int) bool { return g[i] < g[j] })
+ return g
+}

proc_status_test.go

@@ -14,6 +14,7 @@
 package procfs
 
 import (
+ "reflect"
  "testing"
 )
 
@@ -121,3 +122,19 @@ func TestProcStatusGIDs(t *testing.T) {
  t.Errorf("want uids %s, have %s", want, have)
  }
 }
+
+func TestCpusAllowedList(t *testing.T) {
+ p, err := getProcFixtures(t).Proc(26231)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ s, err := p.NewStatus()
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ if want, have := []uint64{0, 1, 2, 3, 4, 5, 6, 7}, s.CpusAllowedList; !reflect.DeepEqual(want, have) {
+ t.Errorf("want CpusAllowedList %v, have %v", want, have)
+ }
+}