<html>#2194: Memory increase during regridding
<table style='border-spacing: 1ex 0pt; '>
<tr><td style='text-align:right'> Reporter:</td><td>Wolfgang Kastaun</td></tr>
<tr><td style='text-align:right'> Status:</td><td>wontfix</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td>ET_2020_04</td></tr>
<tr><td style='text-align:right'> Version:</td><td>development version</td></tr>
<tr><td style='text-align:right'> Type:</td><td>bug</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>minor</td></tr>
<tr><td style='text-align:right'>Component:</td><td>Other</td></tr>
</table>
<p>Comment (by Roland Haas):</p>
<p>I guess the way to think about this is that “high” RSS alone is not <em>sufficient</em> for an OOM event, however it wold seem <em>necessary</em>. On clusters like BW that have no swap and for codes like Cactus that have little IO that could be cached in memory (and no explicitly <code>mmap</code>ed region) it likely is highly correlated though.</p>
<p>I ran <a data-is-external-link="true" href="https://bitbucket.org/einsteintoolkit/tickets/issues/attachments/2194/einsteintoolkit/tickets/1556718270.57/2194/ML_QC3_memcheck.par" rel="nofollow">ML_QC3_memcheck.par</a> using 8 MPI ranks and either the Proca code or current (pre ET_2020_04) master to check the effects of the patch (which is in master but not in Proca).</p>
<p><img alt="" src="https://bitbucket.org/repo/8zBLME5/images/3082830427-ML_QC3_memcheck.png" />
Clearly the patch reduces RSS compared to Proca but does not avoid the jump at around it=1096. I am not plotting the allocated memory since for this run it seems to exceed 2GB and mallinfo’s output becomes useless. Getting a handle on the allocated memory will require either using some malloc debugger (either for glibc’s malloc or in a replacement library) or implementing #2353 which should take on the order of 2hrs of time and would be an excellent beginner’s project.</p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2194/memory-increase-during-regridding'>https://bitbucket.org/einsteintoolkit/tickets/issues/2194/memory-increase-during-regridding</a></p>
</html>