yade-dev team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxxxxxx>]

Hello all,

I just noticed something I don't think I've ever seen before.
I'm wondering if some recent changes in force containers (I've seen some 
by Anton IIRC) could explain that.
Below are the outputs of "yade --performance" and "yade -j6 
--performance" (same build).
With -j1 the force resetter takes 3.55% of the total cpu time, not 
negligible but ok, we can live with that.
With -j6 the absolute time it takes is multiplied by 3 almost, reaching 
21% in terms of rel. time. This is huge and seriously degradate the 
performance of the parallel run.

Could someone confirm this?

Bruno
______________________
1 CORE

number of bodies 47323

Elapsed  66.9550299644  sec
Performance  20.9095567688  iter/sec
Extrapolation on 1e5 iters  1.32847281675  hours
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*
Name Count                 Time            Rel. time
-------------------------------------------------------------------------------------------------------
ForceResetter                                      1400 
2373474us                3.55%
InsertionSortCollider                                39 
4636343us                6.93%
InteractionLoop                                    1400 
49261433us               73.62%
NewtonIntegrator                                   1400 
10642155us               15.90%
TOTAL 66913407us              100.00%
_______________________
6 CORES

number of bodies 47323

Elapsed  29.4499371052  sec
Performance  47.5383018646  iter/sec
Extrapolation on 1e5 iters  0.584324148912  hours
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*
Name Count                 Time            Rel. time
-------------------------------------------------------------------------------------------------------
ForceResetter                                      1400 
6370788us               21.66%
InsertionSortCollider                                39 
1957601us                6.66%
InteractionLoop                                    1400 
13912593us               47.30%
NewtonIntegrator                                   1400 
7174500us               24.39%
TOTAL 29415483us              100.00%

--
_______________
Bruno Chareyre
Associate Professor
ENSE³ - Grenoble INP
Lab. 3SR
BP 53
38041 Grenoble cedex 9
Tél : +33 4 56 52 86 21
Fax : +33 4 76 82 70 43
________________

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