Notes 2020 04 30

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Marc-Andre Hermanns edited this page May 6, 2020 · 1 revision

Meeting 2020-04-30

Participants

Marc-Andre Hermanns
Michael Knobloch
Bengisu Elis
Bharath Ramesh
Joachim Protze
John DelSignore
Kathryn Mohror
Martin Schulz

Topics

Handle Introspection

How to implement the prototype
- PMPI-based implementation favored
  - Direct integration into one of the MPI implementations may be too daring without direct involvement of one of the core developers
This is a third party interface
- Similar to OMPD
  - Focussing on opaque handles
- First get a debugging handle for an MPI handle
  - Use debugging handle further on
- Bootstrapping problem also applies here
- OMPD was partly inspired by handle introspection/MQD
  - Leverage common characterisitcs
- Potentially develop a first party interface from this
Wiki vs. Issue vs. Google Doc?
- Brainstorm/Sketch via Google Docs Presentation (that can easily be used to present at a meeting)
- Work on a specific issue once concepts are clear and we work on the text
Proposal has to core topics
- Bootstrap
  - Getting Debugger & Library in touch
  - Initializing the library
    - ompd_initialize & ompd_process_initialize
    - Would this be different for MPI? Would this work for MPI?
      - Each process might have a different DLL
        
        On each node each process will likely use the same MPI library
        
        Interface still supports the case where it would be different
  - Providing the callbacks
  - List of shared-library names
    - Variable (argv-style vector) ompd_dll_locations
    - Rules in the standard
    - OMPD Env-Var informs runtime about presence of debugger
- Library
  - Interaction with debugger
Use Cases
- Debug inconsistent states of handles