# prctl -n task.max-lwps -v 40 -t privileged -d all `pgrep httpd`
# rctladm -e syslog task.max-lwps
If it does, you will see /var/adm/messages such as:
Jan 8 10:15:15 testmachine unix: [ID 859581 kern.notice] NOTICE: privileged rctl task.max-lwps exceeded by task 19