Reported on discord by user here.

Description of the issue:

User "Enzi":
{quote}
hello @daniel-holz hope you are the right one for this. i was stress testing physics a lot and the CreateRigidBodies job peeked my interest. there's a NativeParallelHashMap<Entity, int>.ParallelWriter EntityBodyIndexMap that is very expensive and only used for reading in a subsequent job CreateJoints which is never called when numJoints is 0. removing this saves a LOT of job time so i hope you can find ways to optimize this.
{quote}