Debugging PVM and DPVM Applications

You can debug applications that use the Parallel Virtual Machine (PVM) library or the Compaq Tru64 UNIX Parallel Virtual Machine (DPVM) library with TotalView on some platforms. TotalView supports ORNL PVM 3.4.1 on the Compaq Alpha, Hewlett-Packard, Sun 5, RS/6000, and SGI IRIX platforms and DPVM 1.4 or later on the Compaq Alpha platform.

Note:   See the TotalView Platforms document for the most up-to-date information regarding your PVM or DPVM software.

For tips on debugging parallel applications, see Parallel Debugging Tips.

Supporting Multiple Sessions

When you debug a PVM or DPVM application, TotalView becomes a PVM tasker. This lets it establish a debugging context for your session. You can run:

• One TotalView PVM or DPVM debugging session for a user and for an architecture; that is, different users cannot interfere with each other on the same machine or same machine architecture.

  One user can start TotalView to debug the same PVM or DPVM application on different machine architectures. However, a single user cannot have multiple instances of TotalView debugging the same PVM or DPVM session on a single machine architecture.

  For example, suppose you start a PVM session on Sun 5 and Compaq Alpha machines. You must start two TotalView sessions: one on the Sun 5 machine to debug the Sun 5 portion of the PVM session, and one on the Compaq Alpha machine to debug the Compaq Alpha portion of the PVM session. These two TotalView sessions are separate and do not interfere with one another.

• Similarly, in one TotalView session, you can run either a PVM application or a DPVM application, but not both. However, if you run TotalView on a Compaq Alpha, you can have two TotalView sessions: one debugging PVM and one debugging DPVM.