HPD -- A High Performance Debugger Implementation

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HPD -- A High Performance Debugger Implementation

• A Parallel Tools Consortium project
• http//www.ptools.org/

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Work funded by the DoD High Performance
Computing Modernization Program, ARL, CEWES, and
NAVO Major Shared Resource Centers, through
Programming Environment and Training
(PET). Views, opinions, and/or findings
contained in this report are those of the
author(s) and should not be construed as an
official Department of Defense position, policy
or decision unless so designated by other
official documentation.
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What is HPD?

• HPD is an implementation following the standard
  proposed by The High Performance Debugger Forum.
• A debugger for parallel and multi-threaded
  applications.
• Is light weight, easy to use and presents
  multiprocess/multithread information in a format
  that is easy to understand.

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What is the High Performance Debugger Forum?

• The Forum was sponsored by The Ptools Consortium
• The goals were to define a useful and appropriate
  set of standards relevant to debugging tools for
  HPC systems and to accommodate needs of both
  users and tool developers.
• http//www.ptools.org/hpdf/

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The High Performance Debugger Standard

• The standard was written to address the following
  types of programs
• high performance in nature (i.e., performance
  is an important consideration) and typically
  parallel
• written in one or more high-level languages
• intended to run on possibly many different
  computer systems
• The standard assumes explicit parallelism as the
  basic programming model.
• The standard is applicable to both shared-memory
  programming (multiple threads of execution in an
  address space) and distributed-memory programming
  (multiple processes co-operating via
  message-passing libraries, such as PVM or MPI)

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The High Performance Debugger Standard

• The standard distinguishes the functionality
  needed for threads-only, process-only and
  multilevel (multi-process and multi-thread)
  models of parallelism
• The overall objective of the standard is to make
  it possible for debuggers of all three types to
  provide support that is consistent as possible,
  given the constraints imposed by the underlying
  model.
• The major languages considered were Fortran (F77
  and F90), C, and C.

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Who is doing what

• Oregon State University developed the parser for
  the command line debugger
• University of Tennessee is working on
  implementing the rest of the debugger and writing
  the DBX client
• University of Tennessee and Robert Hood from NASA
  are working on making the p2d2 internal code
  modular so it can be used in this project as a
  basis for HPD.

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Implementation Details

• There are several layers to make the
  implementation modular
• Front-end (e.g. command line, GUI )
• Data Management Layer
• Debugger Server Layer
• Client Layer (e.g. GDB, DBX, etc)
• The Data Management Layer contains all the group
  and process information.

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Implementation Details (cont.)

• The client layer parses output, sends the
  commands to the various debuggers.
• Each process will have one debugger attached to
  it. The control of these debuggers will be
  through the front-end

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p2d2/HPDs Client-server Architecture
remote server
a.out
user interface
distribution manager
debugger server
remote server
a.out
client
remote server
a.out
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What will the beta release contain (est. Feb 99)?

• A subset version of the command line debugger
  implementing the following
• run, continue, break, print, where
• Due to memory issues run will only work the first
  time you use it, then you must exit out and
  restart the debugger
• GDB will be the only debugger supported initially.

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Future Work

• DBX as the per-process debugger
• Add functionality to implement as much of the
  standard as possible
• Memory clean-up routines
• Make the code more modular

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For More Information

• http//icl.cs.utk.edu/projects/hpd/
• http//www.ptools.org/
• http//www.ptools.org/hpdf/
• http//www.ptools.org/hpdf/draft/