deallocate unused virtual consoles
see also :
chvt - openvt
add an example, a script, a trick and tips
state_exists console || exit 1
chvt $(restorestate console)
deallocvt deallocates kernel memory and data
structures for all unused virtual consoles. If one or more
arguments N ... are given, only the corresponding
consoles /dev/ttyN are deallocated.
console is unused if it is not the foreground console, and
no process has it open for reading or writing, and no text
has been selected on its screen.