Are you sure that dunecontrol finds MPI? Can you post the output of
dunecontrol?
Bernd
On 01/30/2019 12:46 PM, lc wrote:
Good morning,
I updated the virtual machine as you may see from the lscpu_new file
attached.
Then, I try to run both sequential 2p test_impesadaptive and 2p
implicit test_box2p (input file attached) with 1 4 and 8 cores
straight from the Dumux 2.12 test suite without any other modification
(just the grid in the input file).
I still get the same behaviour:
1 core -> 302 s
4 cores -> 337 s (output attached)
8 cores -> 470 s
It seems that as you noted, these processes do not communicate each
other. Do you agree?
These testcases, should be fully parallel, so what's wrong?
Thank you,
P.S. I also have other pending questions ...
Kind regards,
Lorenzo
On 24.01.2019 14:42, Flemisch, Bernd wrote:
Timo is of course right. Nevertheless, your parallel output shows
that the program isn't executed in a distributed way. It simply
executes the full sequential code on four processes that don't
communicate with each other. The four processes occupy two physical
cores resulting in a degradation in performance. The sequential (in
the sense of temporal discretization and coupling) 2p2c model is not
parallel. The fully implicit ones are parallel, also the sequential
2p model is parallel. Let us know if you experience the same problems
with a truly parallel model. If you do so, please consider Timo's
comment that you choose a number of processes that is less or equal
than the number of physical cores on your machine.
Kind regards
Bernd
--
_______________________________________________________________
Bernd Flemisch phone: +49 711 685 69162
IWS, Universität Stuttgart fax: +49 711 685 60430
Pfaffenwaldring 61 email: be...@iws.uni-stuttgart.de
D-70569 Stuttgart url: www.hydrosys.uni-stuttgart.de
_______________________________________________________________
------------------------------------------------------------------------
*Von:* Dumux <dumux-boun...@listserv.uni-stuttgart.de> im Auftrag von
Timo Koch <timo.k...@iws.uni-stuttgart.de>
*Gesendet:* Donnerstag, 24. Januar 2019 11:01:56
*An:* DuMuX User Forum; lc
*Betreff:* Re: [DuMuX] set_singular_limit and parallel execution
Hi Lorenzo,
you can't scale well to 4 cores because your CPU only has two cores.
The two additional ones are only hyperthreads. Please repeat the same
numerical experiment on a machine with more cores.
Timo
On 24.01.19 10:37, lc wrote:
On 18.01.2019 21:52, Flemisch, Bernd wrote:
Can you please post the complete output for the run with 4 cores?
Plus the initial vtk files? And, pretty please with sugar on top,
the number of physical cores on your machine?
Good morning,
I enclose the requested files for the sequential (1 processor) and
parallel (4 processors) simulations plus some detail on my machine.
Thanks for help,
Lorenzo
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_______________________________________________________________
Timo Koch phone: +49 711 685 64676
IWS, Universität Stuttgart fax: +49 711 685 60430
Pfaffenwaldring 61 email:timo.k...@iws.uni-stuttgart.de
D-70569 Stuttgart url:www.hydrosys.uni-stuttgart.de
_______________________________________________________________
--
_______________________________________________________________
Bernd Flemisch phone: +49 711 685 69162
IWS, Universität Stuttgart fax: +49 711 685 60430
Pfaffenwaldring 61 email: be...@iws.uni-stuttgart.de
D-70569 Stuttgart url: www.hydrosys.uni-stuttgart.de
_______________________________________________________________
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