[mpiwg-tools] Intel MPI Backend Breakpoint

[Alexander Zahdeh]

Hi,

This is Alex Zahdeh, one of the debugger tools developers at Cray. I had 
a question about how Intel MPI handles synchronization according to the 
MPIR debugging standard. The usual procedure for our debugger is to 
launch tool daemons to attach to the backend application processes while 
the application launcher is held at MPIR_Breakpoint. At this point the 
application process must be in some sort of barrier so the debugger 
tries to return the user to their own code by setting breakpoints at 
various initialization symbols for different parallel models, 
continuing, hitting one of the breakpoints, deleting the rest and 
finishing the current function. This works if the application is held 
before the breakpoints we set which does not seem to be the case with 
Intel MPI. Is there a more standard approach to returning the user to 
their own code or does it vary by programming model and implementor? And 
specifically with Intel MPI would there be a good breakpoint to set in 
this scenario?

Thanks much,
Alex
-- 
Alex Zahdeh | PE Debugger Development | Cray Inc.
azahdeh at cray.com | Office: 651-967-9628 | Cell: 651-300-2005