<div dir="ltr">Anna,<div>This parallels my experience in running v.surf.rst with OpenMP enabled and disabled on large areas. With OpenMP enabled on an 8 core computer, the process used 700% of CPU time, but took about twice as long as running the same data set on a single core with OpenMP disabled.<br>
</div><div><br></div><div>Doug</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Aug 6, 2014 at 10:58 PM, Anna Petrášová <span dir="ltr"><<a href="mailto:kratochanna@gmail.com" target="_blank">kratochanna@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi,<br><div class="gmail_extra"><br><br><div class="gmail_quote"><div class="">On Tue, Aug 5, 2014 at 11:04 AM, Newcomb, Doug <span dir="ltr"><<a href="mailto:doug_newcomb@fws.gov" target="_blank">doug_newcomb@fws.gov</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Anna,<div>Will you post the benchmarking results for the OpenMP computation vs the non-OpenMP?</div>
<div><br></div></div></blockquote><div><br></div></div><div>after some testing, my conclusion is that OpenMP does not really speed up gradient computation and it can even slow it down. I tried it on my laptop with 2 cores and on a powerful computer with 12 cores, with different sizes of processed blocks and I didn't get any significant speed-up. The most costly seems to be writing of the three 3D rasters and the gradient computation is relatively short. I also tested different cache settings but default settings seems to be optimal, I got only similar or worse results with different cache settings. I hope I didn't missed anything, since this is quite new to me. </div>
<div><br></div><div>Best,</div><div><br></div><div>Anna</div><div><div class="h5"><div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div dir="ltr"><div></div><div>Doug</div></div><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div>On Fri, Aug 1, 2014 at 3:54 PM, Anna Petrášová <span dir="ltr"><<a href="mailto:kratochanna@gmail.com" target="_blank">kratochanna@gmail.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div><div><div dir="ltr"><span style="font-family:arial,sans-serif;font-size:13px">Hi,</span><br style="font-family:arial,sans-serif;font-size:13px">
<br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">1. What did you get done this week:</span><br style="font-family:arial,sans-serif;font-size:13px">
<font face="arial, sans-serif">I implemented adding attributes to each segment of a flowline. I added column with velocities and values of input 3D raster along the flowline. The result can be visualized by using vector color tables (v.colors) in 2D and 3D.</font><div>
I started writing r3.gradient module based on the gradient function in r3.flow. The module is already running and giving correct results, I will add it to addons once the gradient function is moved to library.<br style="font-family:arial,sans-serif">
<br style="font-family:arial,sans-serif;font-size:13px"><span style="font-family:arial,sans-serif;font-size:13px">2. What do you plan on doing next week?</span><div>I will try to parallelize the gradient computation with openMP, the structure of the code is already prepared for that. Then, I plan to add more tests.<br>
<br><font face="arial, sans-serif">3. Are you blocked on anything?</font><br><font face="arial, sans-serif" style="font-family:arial,sans-serif;font-size:13px">No.</font><br><br><font face="arial, sans-serif">Anna</font><br>
<br><font face="arial, sans-serif">[1] </font><a href="http://trac.osgeo.org/grass/wiki/GSoC/2014/ImplementationOf3DRasterFlowLine" style="font-family:arial,sans-serif;font-size:13px" target="_blank">http://trac.osgeo.org/grass/wiki/GSoC/2014/ImplementationOf3DRasterFlowLine</a><br>
<font face="arial, sans-serif">[2] </font><a href="http://trac.osgeo.org/grass/browser/grass-addons/grass7/raster3d/r3.flow" style="font-family:arial,sans-serif;font-size:13px" target="_blank">http://trac.osgeo.org/grass/browser/grass-addons/grass7/raster3d/r3.flow</a></div>
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<br clear="all"><div><br></div>-- <br><div>Doug Newcomb</div><div>
USFWS</div><div>Raleigh, NC</div><div><a href="tel:919-856-4520%20ext.%2014" value="+19198564520" target="_blank">919-856-4520 ext. 14</a> <a href="mailto:doug_newcomb@fws.gov" target="_blank">doug_newcomb@fws.gov</a></div>
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<div>The opinions I express are my own and are not representative of the official policy of the U.S.Fish and Wildlife Service or Dept. of the Interior. Life is too short for undocumented, proprietary data formats.</div>
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</blockquote></div></div></div><br></div></div>
</blockquote></div><br><br clear="all"><div><br></div>-- <br><div>Doug Newcomb</div><div>USFWS</div><div>Raleigh, NC</div><div>919-856-4520 ext. 14 <a href="mailto:doug_newcomb@fws.gov" target="_blank">doug_newcomb@fws.gov</a></div>
<div>---------------------------------------------------------------------------------------------------------</div><div>The opinions I express are my own and are not representative of the official policy of the U.S.Fish and Wildlife Service or Dept. of the Interior. Life is too short for undocumented, proprietary data formats.</div>
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