Notes 2019 07 18

Participants

• Chris Chambreau
• Josh Cottingham
• Bengisu Elis
• Marc-Andre Hermanns
• Nathan Hjelm
• Kathryn Mohror
• Martin Schulz

Topics

QMPI

• What are the lessons learned from Bengisu's Master Thesis?
  • Some shortcuts taken due to time constraints need to be addressed
  • Bengisu will give a code walk-through as part of the Meeting at Aug 1, 2019.
• Do we need a pointer to the last user code function to ease demarcation of user vs. MPI/Tool functions when stack walking?
  • The MPI symbol called by the user should be known by the tool, so this might not be necessary
    • The last user function is one level up of that symbol
  • If this is not portabely possible, what other options to we have?
    • Is there a portable compiler macro to provide the function pointer of the current function to a function called within said function?
      • This could short-cut the stack walking needed for tools to find the entry into MPI
      • Could be a runtime/measurement-time benefit
    • Matt LeGendre (LLNL) will join the Meeting at Jul 25, 2019 to discuss the details of stack walking, what's possible, what's not possible, and what would be useful for tools to have