I'm not sure if this is something that should be fixed or not. I'm opening this issue for two main reasons:

• to hopefully save others the effort I went through to find the cause of this contention
• in case a shared AuthorizationManager is a cause of the contention in Is there a way to use RunspacePools such that module loading uses more than one processor? #7035's repro

Steps to reproduce

Invoke authorizationManagerContention.ps1.

Expected behavior

I expected the amount of time it takes to open runspaces in parallel to be similar whether AuthorizationManager is shared or not.

Actual behavior

Sharing AuthorizationManager causes an approximately 0.5x slow down on my 16-core test system.

ProcessorCount: 16

Name    Elapsed(ms)
----    -----------
One Per        3764
Shared         6974

Environment data

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      6.1.0-preview.691
PSEdition                      Core
GitCommitId                    v6.1.0-preview.691
OS                             Microsoft Windows 6.3.9600
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0