LDM 6.5.1 Known Problems
On some Linux systems, an ldmadmin stop command can
hang because a downstream LDM process hangs.
An strace(1) of the hung process indicates that it is
repeatedly invoking the futex system-call:
futex(0x583844, FUTEX_WAIT, 2, NULL) = -1 EINTR (Interrupted system call)
--- SIGCONT (Continued) @ 0 (0) ---
futex(0x583844, FUTEX_WAIT, 2, NULL) = -1 EINTR (Interrupted system call)
--- SIGCONT (Continued) @ 0 (0) ---
...
This is a known Linux bug. Fixing it requires modifying either the Linux
kernel or the gcc runtime library or both. The bug appears to exist in all
2.6 versions prior to and including version 2.6.13. Further information
can be found by Googling "futex hang".
A workaround appears to be to set the environment variable
LD_ASSUME_KERNEL to 2.4.19 before executing any
LDM program. For best effect, this should be done in the LDM user's
profile-file.
If you encounter bugs or problems, please contact support at unidata.ucar.edu.
Include in the email all relevant items that could aid the diagnosis.
