yade-dev team mailing list archive

["Eulitz, Alexander" <Alexander.Eulitz@xxxxxxxxxxxxxxxx>]

Hi Bruno,

do you think that the problem exists for a while or when did openMP issues arise?

regards

Alex

 

Von: Yade-dev [mailto:yade-dev-bounces+alexander.eulitz=iwf.tu-berlin.de@xxxxxxxxxxxxxxxxxxx] Im Auftrag von Bruno Chareyre
Gesendet: Freitag, 16. September 2016 00:19
Cc: Yade developers
Betreff: Re: [Yade-dev] Regression in ForceResetter?

 

Wait...

Now I realize that the timings are weird. Real times are the same, relative times are different.

It could be that the counting is wrong. Something system/hardware dependent.

We have troubles with openMP at the moment. So forget it.

Thanks for the link anyway Anton.

B

 

On 15 September 2016 at 19:42, Anton Gladky <gladky.anton@xxxxxxxxx> wrote:

Hi Bruno,

the only more-less relevant commit is the following [1]. Try to comment
that line and check, whether the regression is no more visible. If it
is so, that problem (described in commit log) should be solved by
more elegant way.

[1] https://github.com/yade/trunk/commit/07940b52ac31597c07d9d98f2891311d7e6d8e0e

Cheers

Anton



2016-09-15 19:23 GMT+02:00 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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>
>
>

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