TotalView Users Guide - CI Wiki

Debugging Shared Memory (SHMEM) Code
3 If the task to which you attached has related tasks that can be debugged,
TotalView asks if you want to attach to these related tasks. If you answer
Yes, TotalView attaches to them. If you answer No, it only attaches to the
task you dove on.
After attaching to a task, TotalView looks for attached tasks that are related
to this task; if there are related tasks, TotalView places them in the same
control group. If TotalView is already attached to a task you dove on, it simply
opens and raises the Process Window for the task.
About Reserved Message Tags
TotalView uses PVM message tags in the range 0xDEB0 through 0xDEBF to
communicate with PVM daemons and the TotalView Server. Avoid sending
messages that use these reserved tags.
Cleaning Up Processes
The pvmgs process registers its task ID in the PVM database. If the pvmgs
process terminates, the pvm_joingroup() routine hangs because PVM won’t
clean up the database. If this happens, you must manually terminate the
program and then restart the PVM daemon.
TotalView attempts to clean up the tvdsvr processes that also act as
taskers. If some of these processes do not terminate, you must manually
terminate them.
Debugging Shared Memory
(SHMEM) Code
TotalView supports programs using the distributed memory access Shared
Memory (SHMEM) library on Quadrics RMS systems and SGI Altix and IRIX
systems. The SHMEM library allows processes to read and write data
stored in the memory of other processes. This library also provided collective
operations.
Debugging a SHMEM RMS or SGI Altix program is no different than debugging
any other program that uses a starter program. For example:
totalview srun -a my_program
Debugging a SHMEM program running on SGI IRIX requires the following:
1 Link the SHMEM program with the dbfork library. See “Linking with the
dbfork Library” in the “Compilers and Platforms” chapter of the TotalView Reference
Guide.
2 Start TotalView on your program. (See Chapter 4, “Setting Up a
Debugging Session,” on page 51.)
156 Chapter 7: Setting Up Parallel Debugging Sessions