Server 100% cpu on new empty world

When I start a new empty world I get 100% cpu

(even when play that world for a while it keeps hanging on 100%)

 

It looks like somthing is hanging

I made a new world profile and console log in attachment

 

(Linux environment)

java="/home/minecraft/jre1.8.0_111/bin/java"

$java -Xms256M -Xmx4G -jar server.jar nogui