Paper: 100% CPU usage on start up - powerful cpu

[danielboos1]

Timings or Profile link:

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Description of issue:

___If applicable___
When starting the server my CPU usage usually goes to 100% considering that I have a 8 thread 4 cores CPU running at 3.9ghz is insane to be honest. Also it takes a while to start up for me

Plugin list:

___All plugins running on the server___
Metrix anti cheat
Geysermc
Protocollib

bukkit.yml, spigot.yml, paper.yml, server.properties

___Gist/pastebin/hastebin links___

Other helpful links

___The more information we receive, the quicker and more effective we can be at finding the solution to the
issue.___

Paper build number:

___This can be found by running /version on your server. latest is not a proper version number; we require the output of /version so we can properly track down the issue.___
226

[paul0665]

I think this is normal, server need time to start up.

All of my server will do that too.

[pop4959]

Do you have any comparison to make with older versions of Paper? I don't see any regressions.

paper-143: [01:28:23 INFO]: Done (8.722s)! For help, type "help"

paper-229: [01:29:35 INFO]: Done (1.588s)! For help, type "help"

[aikar]

Working as intended. Mojang has to build data fixers at startup which is extremely resource intensive and uses all threads.
then loading spawn chunks again uses a nice burst.

Nothing can be done about this

[danielboos1]

cant you build data fixers once then cache them? this was a nice example showing that even on one of the most powerful CPUs it hits 100%

[paul0665]

The high usage for short time shouldn't effect anything. If you still want it, you can try docker.

[aikar]

It is not possible to cache them no.
If you want to analyze the code and make some suggestions to mojang, the code is here: https://github.com/Mojang/DataFixerUpper