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Fix cpu share issues on systems with large amounts of cpu

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On systems where the calculated cpu shares results in a value above the
max value in linux, containers getting that value are unable to start.
This occur on systems with 300+ cpu cores, and where containers are
given such a value.

This issue was fixed for the pod and qos control groups in the similar
cm.MilliCPUToShares that also has tests verifying the behavior. Since
this code already has an dependency on kubelet/cm, lets reuse that code
instead.
This commit is contained in:
Odin Ugedal 2021-11-14 19:45:47 +00:00
parent e4c795168b
commit de0ece541c
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3 changed files with 3 additions and 25 deletions
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17
pkg/kubelet/kuberuntime/helpers_linux.go
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@ -20,9 +20,6 @@ limitations under the License.
package kuberuntime package kuberuntime
const ( const (
// Taken from lmctfy https://github.com/google/lmctfy/blob/master/lmctfy/controllers/cpu_controller.cc
minShares = 2
sharesPerCPU = 1024
milliCPUToCPU = 1000 milliCPUToCPU = 1000
// 100000 is equivalent to 100ms // 100000 is equivalent to 100ms
@ -30,20 +27,6 @@ const (
minQuotaPeriod = 1000 minQuotaPeriod = 1000
) )
// milliCPUToShares converts milliCPU to CPU shares
func milliCPUToShares(milliCPU int64) int64 {
if milliCPU == 0 {
// Return 2 here to really match kernel default for zero milliCPU.
return minShares
}
// Conceptually (milliCPU / milliCPUToCPU) * sharesPerCPU, but factored to improve rounding.
shares := (milliCPU * sharesPerCPU) / milliCPUToCPU
if shares < minShares {
return minShares
}
return shares
}
// milliCPUToQuota converts milliCPU to CFS quota and period values // milliCPUToQuota converts milliCPU to CFS quota and period values
func milliCPUToQuota(milliCPU int64, period int64) (quota int64) { func milliCPUToQuota(milliCPU int64, period int64) (quota int64) {
// CFS quota is measured in two values: // CFS quota is measured in two values:

5
pkg/kubelet/kuberuntime/helpers_unsupported.go
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@ -18,8 +18,3 @@ limitations under the License.
*/ */
package kuberuntime package kuberuntime
// milliCPUToShares converts milliCPU to CPU shares
func milliCPUToShares(milliCPU int64) int64 {
return 0
}

6
pkg/kubelet/kuberuntime/kuberuntime_container_linux.go
View File

@ -139,11 +139,11 @@ func (m *kubeGenericRuntimeManager) calculateLinuxResources(cpuRequest, cpuLimit
// API server does this for new containers, but we repeat this logic in Kubelet // API server does this for new containers, but we repeat this logic in Kubelet
// for containers running on existing Kubernetes clusters. // for containers running on existing Kubernetes clusters.
if cpuRequest.IsZero() && !cpuLimit.IsZero() { if cpuRequest.IsZero() && !cpuLimit.IsZero() {
cpuShares = milliCPUToShares(cpuLimit.MilliValue()) cpuShares = int64(cm.MilliCPUToShares(cpuLimit.MilliValue()))
} else { } else {
// if cpuRequest.Amount is nil, then milliCPUToShares will return the minimal number // if cpuRequest.Amount is nil, then MilliCPUToShares will return the minimal number
// of CPU shares. // of CPU shares.
cpuShares = milliCPUToShares(cpuRequest.MilliValue()) cpuShares = int64(cm.MilliCPUToShares(cpuRequest.MilliValue()))
} }
resources.CpuShares = cpuShares resources.CpuShares = cpuShares
if memLimit != 0 { if memLimit != 0 {