croup cpu: add support for realtime throttling

Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>

cgroups/fs/cpu.go

@@ -44,6 +44,16 @@ func (s *CpuGroup) Set(path string, cgroup *configs.Cgroup) error {
 			return err
 		}
 	}
+	if cgroup.CpuRtPeriod != 0 {
+		if err := writeFile(path, "cpu.rt_period_us", strconv.FormatInt(cgroup.CpuRtPeriod, 10)); err != nil {
+			return err
+		}
+	}
+	if cgroup.CpuRtRuntime != 0 {
+		if err := writeFile(path, "cpu.rt_runtime_us", strconv.FormatInt(cgroup.CpuRtRuntime, 10)); err != nil {
+			return err
+		}
+	}
 
 	return nil
 }

cgroups/fs/cpu_test.go

@@ -46,15 +46,23 @@ func TestCpuSetBandWidth(t *testing.T) {
 		quotaAfter      = 5000
 		periodBefore    = 10000
 		periodAfter     = 7000
+		rtRuntimeBefore = 8000
+		rtRuntimeAfter  = 5000
+		rtPeriodBefore  = 10000
+		rtPeriodAfter   = 7000
 	)
 
 	helper.writeFileContents(map[string]string{
 		"cpu.cfs_quota_us":  strconv.Itoa(quotaBefore),
 		"cpu.cfs_period_us": strconv.Itoa(periodBefore),
+		"cpu.rt_runtime_us": strconv.Itoa(rtRuntimeBefore),
+		"cpu.rt_period_us":  strconv.Itoa(rtPeriodBefore),
 	})
 
 	helper.CgroupData.c.CpuQuota = quotaAfter
 	helper.CgroupData.c.CpuPeriod = periodAfter
+	helper.CgroupData.c.CpuRtRuntime = rtRuntimeAfter
+	helper.CgroupData.c.CpuRtPeriod = rtPeriodAfter
 	cpu := &CpuGroup{}
 	if err := cpu.Set(helper.CgroupPath, helper.CgroupData.c); err != nil {
 		t.Fatal(err)
@@ -75,6 +83,20 @@ func TestCpuSetBandWidth(t *testing.T) {
 	if period != periodAfter {
 		t.Fatal("Got the wrong value, set cpu.cfs_period_us failed.")
 	}
+	rtRuntime, err := getCgroupParamUint(helper.CgroupPath, "cpu.rt_runtime_us")
+	if err != nil {
+		t.Fatalf("Failed to parse cpu.rt_runtime_us - %s", err)
+	}
+	if rtRuntime != rtRuntimeAfter {
+		t.Fatal("Got the wrong value, set cpu.rt_runtime_us failed.")
+	}
+	rtPeriod, err := getCgroupParamUint(helper.CgroupPath, "cpu.rt_period_us")
+	if err != nil {
+		t.Fatalf("Failed to parse cpu.rt_period_us - %s", err)
+	}
+	if rtPeriod != rtPeriodAfter {
+		t.Fatal("Got the wrong value, set cpu.rt_period_us failed.")
+	}
 }
 
 func TestCpuStats(t *testing.T) {

cgroups/systemd/apply_systemd.go

@@ -294,6 +294,17 @@ func joinCpu(c *configs.Cgroup, pid int) error {
 			return err
 		}
 	}
+	if c.CpuRtPeriod != 0 {
+		if err = writeFile(path, "cpu.rt_period_us", strconv.FormatInt(c.CpuRtPeriod, 10)); err != nil {
+			return err
+		}
+	}
+	if c.CpuRtRuntime != 0 {
+		if err = writeFile(path, "cpu.rt_runtime_us", strconv.FormatInt(c.CpuRtRuntime, 10)); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 

configs/cgroup.go

@@ -39,6 +39,12 @@ type Cgroup struct {
 	// CPU period to be used for hardcapping (in usecs). 0 to use system default.
 	CpuPeriod int64 `json:"cpu_period"`
 
+	// How many time CPU will use in realtime scheduling (in usecs).
+	CpuRtRuntime int64 `json:"cpu_quota"`
+
+	// CPU period to be used for realtime scheduling (in usecs).
+	CpuRtPeriod int64 `json:"cpu_period"`
+
 	// CPU to use
 	CpusetCpus string `json:"cpuset_cpus"`