Pardon my 2nd email, it is irrelevant.
Back to the o.p.: I just checked https://yade-dem.org/wiki/Performance_Test
And the results are somehow similar, large times are allotted to force
resetter in parallel executions of "yade --performance".
So it is not a recent regression.
Something noticeable in Alexander's timing is that the rel time of the
resetter decreases when the number of time iterations is decreased.
It seems there is a constant cost at play in the first iteration. The cost
seem to approach 10% for longer simulations, that's ok maybe.
Cheers
Bruno
On 09/16/2016 09:42 AM, Eulitz, Alexander wrote:
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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