fix the issue that CPU quota is 0 if it's not limited by cgroup

Signed-off-by: Yang Keao <[email protected]>

Author: YangKeao

pkg/util/cgmon/cgmon.go

@@ -38,7 +38,6 @@ var (
 	ctx             context.Context
 	cancel          context.CancelFunc
 	wg              sync.WaitGroup
-	cfgMaxProcs     int
 	lastMaxProcs    int
 	lastMemoryLimit uint64
 )
@@ -116,10 +115,7 @@ func refreshCgroupCPU() error {
 
 	// Get CPU quota from cgroup.
 	cpuPeriod, cpuQuota, err := cgroup.GetCPUPeriodAndQuota()
-	if err != nil {
-		return err
-	}
-	if cpuPeriod > 0 && cpuQuota > 0 {
+	if err == nil && cpuPeriod > 0 && cpuQuota > 0 {
 		ratio := float64(cpuQuota) / float64(cpuPeriod)
 		if ratio < float64(quota) {
 			quota = int(math.Ceil(ratio))
@@ -130,26 +126,25 @@ func refreshCgroupCPU() error {
 		log.Info("set the maxprocs", zap.Int("quota", quota))
 		metrics.MaxProcs.Set(float64(quota))
 		lastMaxProcs = quota
-	} else if lastMaxProcs == 0 {
-		log.Info("set the maxprocs", zap.Int("cfgMaxProcs", cfgMaxProcs))
-		metrics.MaxProcs.Set(float64(cfgMaxProcs))
-		lastMaxProcs = cfgMaxProcs
 	}
-	return nil
+
+	return err
 }
 
 func refreshCgroupMemory() error {
-	memLimit, err := cgroup.GetMemoryLimit()
-	if err != nil {
-		return err
-	}
+	// Get the total memory limit from `procfs`
 	vmem, err := mem.VirtualMemory()
 	if err != nil {
 		return err
 	}
-	if memLimit > vmem.Total {
-		memLimit = vmem.Total
+	memLimit := vmem.Total
+
+	// Try to update the limit from cgroup.
+	cgroupMemLimit, err := cgroup.GetMemoryLimit()
+	if err == nil && cgroupMemLimit < memLimit {
+		memLimit = cgroupMemLimit
 	}
+
 	if memLimit != lastMemoryLimit {
 		log.Info("set the memory limit", zap.Uint64("memLimit", memLimit))
 		metrics.MemoryLimit.Set(float64(memLimit))