kill -16 to get gem stack should be kill -USR1
The 6.1 release notes document the use of kill -16 to cause the
gem's smalltalk stake to be printed to the gem's log file. However,
this should correctly read kill -USR1. USR1 is 16 on Solaris and
HPUX, but on Linux, USR1 is 10, and on AIX, USR1 is 30.
Use kill -USR1