Hi Anders,<br><br>Setting OMP_NUM_THREADS should do fine. Exactly how do you set this? For example for a bash shell, one should 'export' the environment variable export OMP_NUM_THREADS=4<br><br>saji<br><br><br><div class="gmail_quote">
On Thu, Sep 8, 2011 at 6:44 AM, Anders A Nottrott <span dir="ltr"><<a href="mailto:anottrot@ucsd.edu">anottrot@ucsd.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div link="blue" vlink="purple" lang="EN-US"><div><p class="MsoNormal">Hi All,<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">I am trying to run an ideal LES simulation as a parallel process (i.e. using option 'smpar'). I have an 8 core machine but I would like to limit the number of threads to 4. I tried setting the environment variable 'OMP_NUM_THREADS=4' prior to configuration and compilation. However, when I run wrf.exe I get the following just before the simulation begins:<br>
<br>WRF NUMBER OF TILES FROM OMP_GET_MAX_THREADS = 8<br>WRF TILE 1 IS 1 IE 100 JS 1 JE 13<br>WRF TILE 2 IS 1 IE 100 JS 14 JE 26<br>WRF TILE 3 IS 1 IE 100 JS 27 JE 38<br>WRF TILE 4 IS 1 IE 100 JS 39 JE 50<br>WRF TILE 5 IS 1 IE 100 JS 51 JE 62<br>
WRF TILE 6 IS 1 IE 100 JS 63 JE 74<br>WRF TILE 7 IS 1 IE 100 JS 75 JE 87<br>WRF TILE 8 IS 1 IE 100 JS 88 JE 100<br>WRF NUMBER OF TILES = 8<br><br>I looked in 'module_tiles.F' and it appears that the variable 'num_tiles' is assigned by the OMP_GET_MAX_THREADS function. Perhaps this is overriding the environment setting??? Note that when I check my system performance the code is running on all 8 cores, but this is not efficient since I want to run other process on my machine. <u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">I also messed with some of the parameters in the namelist, e.g. ‘tile_sz_x’, ‘tile_sz_y’, ‘numtiles’, ‘nproc_x’, ‘nproc_y’, but to no avail.<u></u><u></u></p><p class="MsoNormal">
<u></u> <u></u></p><p class="MsoNormal">Any suggestions will be most appreciated.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Regards,<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Anders<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><div style="border:none;border-bottom:solid windowtext 1.5pt;padding:0in 0in 1.0pt 0in"><p class="MsoNormal" style="border:none;padding:0in">
<u></u> <u></u></p></div><p class="MsoNormal">Anders Nottrott<u></u><u></u></p><p class="MsoNormal"><i>PhD Student, Mechanical and Environmental Engineering<u></u><u></u></i></p><p class="MsoNormal">University of California, San Diego<u></u><u></u></p>
<p class="MsoNormal">Department of Mechanical and Aerospace Engineering<u></u><u></u></p><p class="MsoNormal">Website: <<a href="http://solar.ucsd.edu/nottrott" target="_blank">solar.ucsd.edu/nottrott</a>><u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p></div></div><br>_______________________________________________<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br><br>Saji N Hameed,<br>ARC-ENV, Center for Advanced Information Science and Technology,<br>University of Aizu, Tsuruga, Ikki-machi,<br>Aizuwakamatsu-shi, Fukushima 965-8580,<br>
Japan<br> <br>Tel: +81242 37-2736<br>Fax:+81242 37-2760<br> email: <a href="mailto:saji@u-aizu.ac.jp" target="_blank">saji@u-aizu.ac.jp</a><br> url: <a href="http://www.u-aizu.ac.jp" target="_blank">http://www.u-aizu.ac.jp</a><br>
bib: <a href="http://www.researcherid.com/rid/B-9188-2009" target="_blank">http://www.researcherid.com/rid/B-9188-2009</a><br>