Charm++ parallel programming system

[François Tessier <francois.tessier AT inria.fr>]

Hello,

I'm looking for some explanations about the measures of time provided by
Charm++ when we call a load balancer. To give an example, I ran some
experiments on a Charm++ application with three load balancers :
DummyLB, GreedyLB and TreeMatchLB. At each LB step, Charm++ gives as
output something like this :

CharmLB> GreedyLB: PE [0] step 0 starting at 51.370771 Memory: 95.647156 MB
CharmLB> GreedyLB: PE [0] strategy starting at 51.553916
[...]
CharmLB> GreedyLB: PE [0] Memory: LBManager: 920 KB CentralLB: 2971 KB
CharmLB> GreedyLB: PE [0] #Objects migrating: 8188, LBMigrateMsg size:
0.52 MB
CharmLB> GreedyLB: PE [0] strategy finished at 52.032098 duration 0.478182 s
CharmLB> GreedyLB: PE [0] step 0 finished at 54.616962 duration 3.246191 s

My question is about the two durations given at the end of the LB step
(duration 1 : 0.478182 s / duration 2 : 3.246191 s). With my
application, the load balancer is called 7 times during the execution.
If I add these durations up :

Duration 1 (strategy finished at... duration ...) :
    GreedyLB      : 2.859333 s
    DummyLB     : 0.001735 s
    TreeMatchLB : 6.762819 s

Duration 2 (step n finished at... duration ...) :
    GreedyLB      : 36.826210 s
    DummyLB     : 122.112121 s
    TreeMatchLB : 136.887350 s

If I look at my own measures in TreeMatchLB, the first duration seems to
correspond to the execution time of the load balancer. Is it true ? What
is the second duration ? How could we explain this 136 seconds for
TreeMatchLB ?

Thanks for your help,

François

-- 
Dr. François TESSIER
University of Bordeaux
Inria - TADaaM Team
Tel : 0033524574152
francois.tessier AT inria.fr
http://runtime.bordeaux.inria.fr/ftessier/
PGP 0x8096B5FA

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