【WIP】koordlet: perform operations only under the specified cpuburst strategy and improve config logging

[yangfeiyu20102011]

Under the specified cpuBurstOnly strategy, the plugin cpuburst still periodically updates the CFS values, which is not expected. Determine the corresponding cpuburst strategy at the beginning and then perform the appropriate actions.

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Ⅱ. Does this pull request fix one issue?

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V. Checklist

• I have written necessary docs and comments
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[codecov]

Codecov Report

Attention: Patch coverage is 71.42857% with 2 lines in your changes missing coverage. Please review.

Project coverage is 67.31%. Comparing base (11701ae) to head (2160c5f).
Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
.../koordlet/qosmanager/plugins/cpuburst/cpu_burst.go	71.42%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2159   +/-   ##
=======================================
  Coverage   67.30%   67.31%           
=======================================
  Files         453      453           
  Lines       43707    43709    +2     
=======================================
+ Hits        29419    29423    +4     
+ Misses      11742    11741    -1     
+ Partials     2546     2545    -1     

Flag	Coverage Δ
unittests	67.31% <71.42%> (+<0.01%)	⬆️

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[saintube]

please note that the strategy should support reseting the related cgroups when the policy disables

[yangfeiyu20102011]

please note that the strategy should support reseting the related cgroups when the policy disables

When both CPUNormalization and CPUBurst are enabled, CFS will be repeatedly changed by the plugins.
How about adding a flag variable, when CPUBurstPolicy changed，call b.applyCPUBurst(cpuBurstCfg, podMeta) and b.applyCFSQuotaBurst(cpuBurstCfg, podMeta, nodeState) as before. @saintube

func (b *cpuBurst) start(){
...
var flag bool
if nodeSLO.Spec.CPUBurstStrategy changed {
flag = true
}
...
if cpuBurstEnabled(cpuBurstCfg.Policy) || flag {
			// set cpu.cfs_burst_us for pod and containers
			b.applyCPUBurst(cpuBurstCfg, podMeta)
}

if cfsQuotaBurstEnabled(cpuBurstCfg.Policy) || flag {
			// scale cpu.cfs_quota_us for pod and containers
			b.applyCFSQuotaBurst(cpuBurstCfg, podMeta, nodeState)
}

}

[saintube]

Maybe we can add a new policy "ignored" to describe the behavior that stops the cgroups reconciliation, so the existing policies are still backward-compatible.

[yangfeiyu20102011]

Maybe we can add a new policy "ignored" to describe the behavior that stops the cgroups reconciliation, so the existing policies are still backward-compatible.

But someone may still want to use cpuBurstOnly, applyCPUBurst() is also needed. @saintube

[saintube]

Yes. The user may switch the policy from auto to cpuBurstOnly. And he/she should reset the cfs_quota.
Adding a separate attribute is a good idea not to break the backward compatibility of the current policies. Possibly, we can define a new field in the CPUBurstStrategy to adjust the configurations dynamically.