Fix cpu resource limit on Windows

This commit is contained in:
Patrick Lang 2019-12-09 18:55:11 -08:00
parent 4e79344501
commit 19acf7d051
4 changed files with 37 additions and 22 deletions

View File

@ -78,6 +78,7 @@ go_library(
"//pkg/kubelet/apis:go_default_library",
"//pkg/kubelet/winstats:go_default_library",
"//vendor/github.com/Microsoft/hcsshim:go_default_library",
"//vendor/github.com/docker/docker/pkg/sysinfo:go_default_library",
"//vendor/golang.org/x/sys/windows/registry:go_default_library",
],
"//conditions:default": [],

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@ -25,6 +25,7 @@ import (
dockertypes "github.com/docker/docker/api/types"
dockercontainer "github.com/docker/docker/api/types/container"
dockerfilters "github.com/docker/docker/api/types/filters"
"github.com/docker/docker/pkg/sysinfo"
"k8s.io/klog"
runtimeapi "k8s.io/cri-api/pkg/apis/runtime/v1alpha2"
@ -69,11 +70,12 @@ func (ds *dockerService) updateCreateConfig(
if wc := config.GetWindows(); wc != nil {
rOpts := wc.GetResources()
if rOpts != nil {
// Precedence and units for these are described at length in kuberuntime_container_windows.go - generateWindowsContainerConfig()
createConfig.HostConfig.Resources = dockercontainer.Resources{
Memory: rOpts.MemoryLimitInBytes,
CPUShares: rOpts.CpuShares,
CPUCount: rOpts.CpuCount,
CPUPercent: rOpts.CpuMaximum,
Memory: rOpts.MemoryLimitInBytes,
CPUShares: rOpts.CpuShares,
CPUCount: rOpts.CpuCount,
NanoCPUs: rOpts.CpuMaximum * int64(sysinfo.NumCPU()) * (1e9 / 10000),
}
}

View File

@ -30,6 +30,7 @@ const (
milliCPUToCPU = 1000
)
// TODO: remove - may be dead code
// milliCPUToShares converts milliCPU to CPU shares
func milliCPUToShares(milliCPU int64, hyperv bool) int64 {
var minShares int64 = minSharesProcess

View File

@ -53,7 +53,6 @@ func (m *kubeGenericRuntimeManager) generateWindowsContainerConfig(container *v1
SecurityContext: &runtimeapi.WindowsContainerSecurityContext{},
}
cpuRequest := container.Resources.Requests.Cpu()
cpuLimit := container.Resources.Limits.Cpu()
isolatedByHyperv := kubeletapis.ShouldIsolatedByHyperV(pod.Annotations)
if !cpuLimit.IsZero() {
@ -61,7 +60,35 @@ func (m *kubeGenericRuntimeManager) generateWindowsContainerConfig(container *v1
// as only 64 processors are available for execution by a given process. This causes
// some oddities on systems with more than 64 processors.
// Refer https://msdn.microsoft.com/en-us/library/windows/desktop/dd405503(v=vs.85).aspx.
// Since Kubernetes doesn't have any notion of weight in the Pod/Container API, only limits/reserves, then applying CpuMaximum only
// will better follow the intent of the user. At one point CpuWeights were set, but this prevented limits from having any effect.
// There are 3 parts to how this works:
// Part one - Windows kernel
// cpuMaximum is documented at https://docs.microsoft.com/en-us/virtualization/windowscontainers/manage-containers/resource-controls
// the range and how it relates to number of CPUs is at https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-jobobject_cpu_rate_control_information
// For process isolation, these are applied to the job object setting JOB_OBJECT_CPU_RATE_CONTROL_ENABLE, which can be set to either
// JOB_OBJECT_CPU_RATE_CONTROL_WEIGHT_BASED or JOB_OBJECT_CPU_RATE_CONTROL_HARD_CAP. This is why the settings are mutually exclusive.
// Part two - Docker (doc: https://docs.docker.com/engine/api/v1.30)
// If both CpuWeight and CpuMaximum are passed to Docker, then it sets
// JOB_OBJECT_CPU_RATE_CONTROL_ENABLE = JOB_OBJECT_CPU_RATE_CONTROL_WEIGHT_BASED ignoring CpuMaximum.
// Option a: Set HostConfig.CpuPercent. The units are whole percent of the total CPU capacity of the system, meaning the resolution
// is different based on the number of cores.
// Option b: Set HostConfig.NanoCpus integer <int64> - CPU quota in units of 10e-9 CPUs. Moby scales this to the Windows job object
// resolution of 1-10000, so it's higher resolution than option a.
// src: https://github.com/moby/moby/blob/10866714412aea1bb587d1ad14b2ce1ba4cf4308/daemon/oci_windows.go#L426
// Part three - CRI & ContainerD's implementation
// The kubelet sets these directly on CGroups in Linux, but needs to pass them across CRI on Windows.
// There is an existing cpu_maximum field, with a range of percent * 100, so 1-10000. This is different from Docker, but consistent with OCI
// https://github.com/kubernetes/kubernetes/blob/56d1c3b96d0a544130a82caad33dd57629b8a7f8/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1alpha2/api.proto#L681-L682
// https://github.com/opencontainers/runtime-spec/blob/ad53dcdc39f1f7f7472b10aa0a45648fe4865496/config-windows.md#cpu
// If both CpuWeight and CpuMaximum are set - ContainerD catches this invalid case and returns an error instead.
cpuMaximum := 10000 * cpuLimit.MilliValue() / int64(sysinfo.NumCPU()) / 1000
// TODO: This should be reviewed or removed once Hyper-V support is implemented with CRI-ContainerD
// in a future release. cpuCount may or may not be required if cpuMaximum is set.
if isolatedByHyperv {
cpuCount := int64(cpuLimit.MilliValue()+999) / 1000
wc.Resources.CpuCount = cpuCount
@ -80,31 +107,15 @@ func (m *kubeGenericRuntimeManager) generateWindowsContainerConfig(container *v1
wc.Resources.CpuMaximum = cpuMaximum
}
cpuShares := milliCPUToShares(cpuLimit.MilliValue(), isolatedByHyperv)
if cpuShares == 0 {
cpuShares = milliCPUToShares(cpuRequest.MilliValue(), isolatedByHyperv)
}
wc.Resources.CpuShares = cpuShares
if !isolatedByHyperv {
// The processor resource controls are mutually exclusive on
// Windows Server Containers, the order of precedence is
// CPUCount first, then CPUShares, and CPUMaximum last.
// CPUCount first, then CPUMaximum.
if wc.Resources.CpuCount > 0 {
if wc.Resources.CpuShares > 0 {
wc.Resources.CpuShares = 0
klog.Warningf("Mutually exclusive options: CPUCount priority > CPUShares priority on Windows Server Containers. CPUShares should be ignored")
}
if wc.Resources.CpuMaximum > 0 {
wc.Resources.CpuMaximum = 0
klog.Warningf("Mutually exclusive options: CPUCount priority > CPUMaximum priority on Windows Server Containers. CPUMaximum should be ignored")
}
} else if wc.Resources.CpuShares > 0 {
if wc.Resources.CpuMaximum > 0 {
wc.Resources.CpuMaximum = 0
klog.Warningf("Mutually exclusive options: CPUShares priority > CPUMaximum priority on Windows Server Containers. CPUMaximum should be ignored")
}
}
}