Charm++ parallel programming system

[Ronak Buch <rabuch2 AT illinois.edu>]

Hello everyone!

On behalf of the Charm++ development team and contributors, I'm pleased to announce the second release candidate of Charm++ in advance of the upcoming version 7.0.0. Since RC1, fixes have been made to resolve hangs and crashes that came up in testing, along with other minor fixes.

We ask that users take this opportunity to test the latest code with their applications and report any issues encountered. Please note that while a v6.11.0-beta1 was released, there was no v6.11.0 release and there will not be, we decided the changes made were large enough to warrant incrementing the major version number to 7 instead.

The code for this release can be obtained via git by

git clone https://github.com/UIUC-PPL/charm.git
git checkout v7.0.0-rc2

Or downloaded directly from: https://github.com/UIUC-PPL/charm/releases/tag/v7.0.0-rc2

670 commits have been made since the release of version v6.10.2, some of the larger and more exciting improvements in the system include (for a full list, please see the current release notes in the CHANGES file):

• A significant overhaul of the load balancing infrastructure and the
  addition of TreeLB, a new, more flexible and extensible base LB,
  intended to replace the previous CentralLB and HybridBaseLB designs
  (load balancers using these previous designs are still
  supported). Some included strategies have been rewritten to use
  TreeLB, unused and extraneous strategies have been removed. Please
  see https://charm.readthedocs.io/en/latest/charm++/manual.html#load-balancing
  for more information.

• Support for persistent intra-node GPU messages, and experimental support for
  regular (nonpersistent) intra-node GPU messages. This feature allows data to be
  sent to/from GPU memory without going through host memory. Please
  see https://charm.readthedocs.io/en/latest/charm++/manual.html#gpu-support for
  more information.

• Charm++ now builds with CMake by default when using the ./build
  script (requires CMake version 3.4 or higher). The old build system is
  still available by using ./buildold. Please see
  https://charm.readthedocs.io/en/latest/charm++/manual.html#installation-with-cmake
  for more information.