kubelet CFS quota throttling for non integer cpulimit

A previous change set the cgroup cpu.cfs_quota_us value to -1 for
containers in pods in the Guaranteed QoS class.

We can only do this if we're allocating the entire CPU.  For non-
integer CPU allocations we need to set the cpu.cfs_quota_us value
to enforce the CPU limit configured on the container.

Test Plan:
Verified the pods that in the "Guaranteed" QoS class, on hosts that
have "kube-cpu-mgr-policy=static" have cpu.cfs_quota_us set to -1 for
integer cpu value.

Closes-Bug: 1997528

Signed-off-by: Boovan Rajendran <boovan.rajendran@windriver.com>
Change-Id: I33662e67706cee4cb0ce005bb09ce3b5fc717239
This commit is contained in:
Boovan Rajendran 2022-11-30 08:35:13 -05:00
parent 3cf2c41738
commit dd75f3ba3d
2 changed files with 31 additions and 0 deletions

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@ -0,0 +1,30 @@
From 2e957044cbcde858abb9c46d177d5cf4ae1407df Mon Sep 17 00:00:00 2001
From: Boovan Rajendran <boovan.rajendran@windriver.com>
Date: Wed, 30 Nov 2022 04:17:19 -0500
Subject: [PATCH] kubelet CFS quota throttling for non integer cpulimit
Signed-off-by: Boovan Rajendran <boovan.rajendran@windriver.com>
---
pkg/kubelet/cm/internal_container_lifecycle_linux.go | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/pkg/kubelet/cm/internal_container_lifecycle_linux.go b/pkg/kubelet/cm/internal_container_lifecycle_linux.go
index 75406dd8564..05366ab6fcb 100644
--- a/pkg/kubelet/cm/internal_container_lifecycle_linux.go
+++ b/pkg/kubelet/cm/internal_container_lifecycle_linux.go
@@ -39,7 +39,11 @@ func (i *internalContainerLifecycleImpl) PreCreateContainer(pod *v1.Pod, contain
// Disable cgroup CFS throttle at the container level.
// /sys/fs/cgroup/cpu/k8s-infra/kubepods/<pod>/<container>/cpu.cfs_quota_us
// /sys/fs/cgroup/cpu/k8s-infra/kubepods/<pod>/<container>/cpu.cfs_period_us
- if i.cpuManager.GetCPUPolicy() == "static" && v1qos.GetPodQOS(pod) == v1.PodQOSGuaranteed {
+ // We can only set CpuQuota to -1 if we're allocating the entire CPU.
+ // For fractional CPUs the CpuQuota is needed to enforce the limit.
+ cpuQuantity := container.Resources.Requests[v1.ResourceCPU]
+ fractionalCpuQuantity := cpuQuantity.MilliValue()%1000
+ if i.cpuManager.GetCPUPolicy() == "static" && v1qos.GetPodQOS(pod) == v1.PodQOSGuaranteed && fractionalCpuQuantity == 0 {
containerConfig.Linux.Resources.CpuPeriod = int64(100000)
containerConfig.Linux.Resources.CpuQuota = int64(-1)
}
--
2.25.1

View File

@ -13,3 +13,4 @@ kubelet-cpumanager-infra-pods-use-system-reserved-CP.patch
kubelet-cpumanager-introduce-concept-of-isolated-CPU.patch
enable-support-for-kubernetes-to-ignore-isolcpus.patch
cpumanager-policy-static-test-refactor.patch
kubelet-CFS-quota-throttling-for-non-integer-cpulimit.patch