Phylanx Report: September 2018

The thirteenth month of work focused on work in the following areas:

• Submitted a paper to the ESPM2 Workshop at Supercomputing
• Performance analysis
  • Added nightly performance tests
  • Improvements to future allocator
  • Direct actions performance sweeps
  • Blaze tuning experiments
• HPXMP Improvements
• Traveler UI improvements

Organizational Activities and Results

• Weekly group-meeting, minutes:
  • September 6th: https://drive.google.com/open?id=1z36spcGB4BqBeX1Rfc7_IscoBECLYIft
  • September 13th: https://drive.google.com/open?id=1qvSxa3CHX746hphWEyhkwHBmWd2SZ22D
  • September 20th: https://drive.google.com/open?id=1rJRkw1WM3MkauPzTqwAXzTSMm4O-gW5P
  • September 27th: https://drive.google.com/open?id=1mz0KwdH4ye179TMUTx-ByZ9SUaF1eT6_
• Phylanx Seminars:
  • http://phylanx.stellar-group.org/index.php/2018/09/10/phylanx-seminar-plugging-into-the-power-of-phylanx/
  • http://phylanx.stellar-group.org/index.php/2018/09/18/phylanx-seminar-plugging-into-the-power-of-phylanx-ii/
  • http://phylanx.stellar-group.org/index.php/2018/09/24/phylanx-seminar-mathematics-of-tiling-approximations/

Development Activities and Results

• Algorithms Highlighted: Logistic Regression, ALS, Neural Network
• APEX
  • Fixed long-standing bug preventing successful build on POWER8 with Clang 5.0 compilers
  • Collected nearly one month of performance regression data, report available at public web address: http://www.nic.uoregon.edu/~khuck/regression/phylanx
  • Added performance tree viewer interface to the HTML regression report
  • Added nightly check for performance degradation
  • Fixed bug in APEX periodic policies preventing regular shutdown of HPX, utilized in parcel coalescing tests.
• Traveler
  • Updated visual design for Traveler tree to support DAG links
  • Improved Traveler tree interface for integration with nightly regression runs
  • Added infrastructure for multi-part thread dependencies in Traveler Gantt
  • Improved tooltip support across both Traveler tree and Traveler Gantt views
  • UI improvements for both Traveler tree and Traveler Gantt views
• Tiling
  • Theory:
    • Looking at two (mostly) independent formulation of the tiling problem:
      • First version: set of tiling choices are fixed. We model this as a constraint satisfaction problem. Currently we are working on determining its approximation complexity.
      • Second version: tiling is computed in an more explicit manner. We will look into this later.
  • Implementation:
    • Looking at how to extract certain memory access information from a Python program
• Primitives & Algorithms
  • Asynchronous / Synchronous execution of Phylanx primitives are now runtime configurable
  • Set primitive has now been removed from Phylanx
  • Map primitive has now been renamed to fmap
• Python
  • Polyhedral Optimizations in Phylanx
    • Work to transform PhySL code into the polyhedral representation and vice-versa

Repository Activity September 1st – October 1st:

Code statistics

-------------------------------------------------------------------------------
Language                     files          blank        comment           code
-------------------------------------------------------------------------------
C++                            286          11230           3865          56258
C/C++ Header                   200           3827           2396          16716
CMake                           91            796            665           3217
Python                          69           1169           1024           2978
YAML                             2             20             64            342
Markdown                         2             15              0             48
Dockerfile                       2              4             27             47
INI                              1              0              0              8
-------------------------------------------------------------------------------
SUM:                           653          17061           8041          79614
-------------------------------------------------------------------------------

Impact on Other Projects

• Blaze:
  • Making sure HPX backend is used when BLAZE_USE_HPX_THREADS is defined and -fopnmp is used (Pull Request #27)
  • Change the prioritization of SMP implementations (Commit bb25f86)
  • Update the prioritization order of SMP implementations in the tutorial (Commit d518c7c)
• HPX Pull Requests:
  • Enable jemalloc on windows (Pull Request #3471)
  • Enable (existing) code for extracting stack pointer on Power platform (Pull Request #3469)
  • Avoid hang if there is an exception thrown during startup (Pull Request #3468)
  • This patch adds various optimizations extracted from the thread_local_allocator work (Pull Request #3465)