Charm++ parallel programming system

["Galvez Garcia, Juan Jose" <jjgalvez AT illinois.edu>]

Hi Chris,

 

What you say is correct in that load balancing is triggered when all the local objects call AtSync and the LBPeriod timer expires.

 

But as far as blocking is concerned, AtSync is not really a blocking call, it’s just that the common application approach is for an object to stop executing after calling AtSync and to continue after ResumeFromSync.

 

-Juan

 

From: Chris Wailes
Sent: Monday, July 24, 2017 1:41 PM
To: charm
Subject: [charm] Understanding AtSync and LBPeriod

 

From my experimentation it appears that if you call AtSync() before the LBPeriod has elapsed, the application will block until the next load balancing period occurs.  So, if you start an application with an LBPeriod of 0.5 seconds and call AtSync() at 0.25 seconds, it will then block for the period from 0.25 to 0.5 seconds, invoke the load balancer at 0.5 seconds, and then return control to the application.

Is this a correct understanding of how AtSync and LBPeriod are related?

- Chris