To build:
  make in lib, then make in src.

To run:

 1) start the master side:
    $ ptytstm 2>/tmp/m.out
    /dev/pts/4		(echoed at start)

 2) start the slave side
    $ ptytsts /dev/pts/4 2>/tmp/s.out

Rudimentary elapsed time info (in 0.0001s) will be in the .out files.

With the 2.6.31-rc2-00205-gb4b21ca kernel there is no appreciable
delay.  With later kernels there is added delay of ~80 (8ms) during the
master's read (first two columns of m.out) and the slave's write (2nd
and 3rd columns of s.out).
