After creating some processes/threads, I encounter following to errors and the are printed to dmesg.
pmap_mapdev: Couldn't alloc kernel virtual memory
vm_thread_new: kstack allocation failed
System becomes unstable thereafter most of times although it depends on what failed to allocate memory.
This happens on any 10.x releases but not 11 current.
Easiest way to reproduce is use benchmarks/forkbomb
% forkbomb -f
brings the above errors in few seconds.
I recall a special fix applied to 9.x stable a while ago but the change didn't seem to apply to 10.x releases.