If you encounter a kghstack_underflow_internal_2 error in version 11.2.0.4, you are likely to encounter bug 18687067, which was introduced in the 11.2.0.4 release.
In the initial customer report of MOS, typical problems such as the following, usually Lmon or LMS process crash errors are as follows:
Ora-00600:internal error code, arguments: [kghstack_underflow_internal_2], [0x110a10838], [], [], [], [], [], [], [], [], [], []
Ora-1092:opitsk aborting Process
Instance terminated by LMS1, PID = 14024818
A typical trace stack is as follows:
.. kghstack_underflow_internal kghstack_free kccgrd kjxgrf_rr_read kjxgrdd_rr_read kjxgrimember kjxggpoll kjfmact Kjfdact Kjfcln ksbrdp ...
-OR-
Kghstack_underflow_internal kghstack_free ktundo kturcrbackoutonechg ktrgcm ktrget3 ktrget2 KCLGCR ...
The problem was initially reported on the Aix platform, and the main reason for this is from the AIX compiler:
The bug is caused by a AIX compiler issue causing volatile variables in the Oracle kernel does not handled properly.