Merge pull request kubernetes#93248 from giuseppe/cgroup-set-max-shares

kubelet: clamp cpu.shares to max allowed

Author: k8s-ci-robot

pkg/kubelet/cm/helpers_linux.go

@@ -38,8 +38,11 @@ import (
 )
 
 const (
-	// Taken from lmctfy https://github.com/google/lmctfy/blob/master/lmctfy/controllers/cpu_controller.cc
-	MinShares     = 2
+	// These limits are defined in the kernel:
+	// https://github.com/torvalds/linux/blob/0bddd227f3dc55975e2b8dfa7fc6f959b062a2c7/kernel/sched/sched.h#L427-L428
+	MinShares = 2
+	MaxShares = 262144
+
 	SharesPerCPU  = 1024
 	MilliCPUToCPU = 1000
 
@@ -88,6 +91,9 @@ func MilliCPUToShares(milliCPU int64) uint64 {
 	if shares < MinShares {
 		return MinShares
 	}
+	if shares > MaxShares {
+		return MaxShares
+	}
 	return uint64(shares)
 }