I could reproduce panic with the latest uvm_map.c (rev 1.400): https://gist.github.com/rokuyama/dc137b66bdc30440c49d8dedb95b95ea Here, I added "entry" argument for uvm_findspace_invariants(): https://gist.github.com/rokuyama/fbd90c433e4fbc0f505f3b85d47b6f74 Thanks, rin