Issue reported by several people. This mailing list post (from another user) summarizes the same symptoms I see: https://community.jenkins.io/t/people-view-plugin-very-slow/14898 with a post from May 7 (so weekly 2.452 before LTS 2.452.1):

> From: https://community.jenkins.io/u/Oberon

Hello
Since version 2.452, the People View function has been removed, but is available with the new People View plugin.
In my company, we have 7 jenkins instances (deployed in a k8s cluster dedicated to CI/CD).
The problem appears when accessing the dashboard page (after the login screen)
Without the plugin, the dashboard page is displayed in 6 seconds maximum.
With the plugin, the dashboard page on some jenkins takes almost 30 seconds to display.
And on one jenkins in particular, the dashboard page takes almost 3 minutes to display (resulting in several timeouts).
On this jenkins, the People View page displays 185 people (on our other jenkins, this same page displays between 100 and 150 people).
I should point out that these slownesses were absent in versions prior to 2.452, and we don’t have any more people today.
Once the dashboard is displayed correctly, it’s ok, you can disconnect and come back to it; it will be displayed in the correct time.
But if you want to display it much later (30 / 60 minutes) the slowness problem reappears.
Are you experiencing this problem too ?
NB: I had to uninstall the people-view plugin as a workaround so as not to penalize users of our jenkins servers.

In my own case, posted at https://matrix.to/#/!ouJVNKRtaWHFflDvBW:gitter.im/$GPE1gFp2IH5H4eNOqs1nL_YIuImL8qljROv_6OY97LE?via=gitter.im&via=matrix.org&via=minds.com it took a couple of steps to implicate the plugin:

 
Hello, after an update to new LTS this week, there is a problem with the root dashboard and "/manage" page rendering, they lock up for many minutes and then appear. Direct links to jobs, or "/monitoring", are snappy.
 
Per the latter, requests to GET "/" and "/contextMenu" are stuck indeed for hundreds of seconds, mostly in jenkins.model.lazy.AbstractLazyLoadRunMap.getByNumber and a few in file I/O and XML parse apparently. So probably something about loading hordes of historic build XMLs? With the same systems, it was not a problem for previous LTS releases.
 

 
Looking at it a bit deeper, it seems that People View  plugin is at fault for those many lazy loads - was something botched while evicting it from core?
 
 

 
 
timja (Tim Jacomb)