<div dir="ltr">Dear Erik,<div>thank you very much for your help. I resubmitted the run and indeed the error disappeared: the time at which I got the crash before has now been passed with no issues (up to now). I will go on and hope no more errors are encountered. Unless I'm forced to, I'm not planning on changing the grid structure, because I'm comparing Spritz and IllinoisGRMHD and I have already completed the run with the latter code: changing the grid structure in the Spritz run at this point would make the comparison a bit less fair than it is.</div><div><br></div><div>I have just noticed that I forgot to actually attach the files in my previous message: I'm attaching them for real now, even though they are probably not useful anymore.</div><div><br></div><div>Thank you very much again.</div><div><br></div><div>Cheers,</div><div>Lorenzo</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il giorno mer 17 nov 2021 alle ore 15:16 Erik Schnetter <<a href="mailto:schnetter@gmail.com">schnetter@gmail.com</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Lorenzo<br>
<br>
Thank you for the detailed analysis of the error location. This helps a lot!<br>
<br>
This is likely caused by an integer division by zero. If you look at<br>
the first error<br>
"Cactus/arrangements/Carpet/CarpetLib/src/defs.hh:144", you see that<br>
this function calculates an integer modulo. Signal 8 is a floating<br>
point exception, which is also raised for integer math, in particular<br>
for division by zero.<br>
<br>
It seems that this happens during output, while determining which<br>
regions of the grid are output. The modulo operations there are<br>
usually used either for error checking or to determine whether coarse<br>
and fine grid points are aligned.<br>
<br>
I don't know what would cause this problem. It could be that the error<br>
goes away if you try again. It might also be caused by a weird grid<br>
structure. Carpet has a lot of checks to ensure that the grid<br>
structure is reasonable, but these checks seem to fail sometimes. If<br>
that is the case, then a minor change to the grid structure (making<br>
refined regions slightly larger or smaller) might avoid the error. It<br>
might also be that changing the number of MPI processes helps, since<br>
this would change the domain decomposition of the grid structure.<br>
<br>
To investigate further we would need to know the grid structure at the<br>
time when the error occurs.<br>
<br>
-erik<br>
<br>
On Wed, Nov 17, 2021 at 2:30 PM Lorenzo Ennoggi<br>
<<a href="mailto:lorenzo.ennoggi@gmail.com" target="_blank">lorenzo.ennoggi@gmail.com</a>> wrote:<br>
><br>
> Hi,<br>
> one of my BNS simulations with the Spritz code started from a checkpoint and, after running for about one day, crashed with exit code 8. The error seems to be related to the Einstein Toolkit infrastructure, so I am posting this message on this mailing list. I am attaching the stdout and stderr (even though they don't look very informative) and the backtrace.<br>
><br>
> Running addr2line -e <Cactus executable> <address> with the <address> listed at point 3 in the backtrace, I see that the error originates from Cactus/arrangements/Carpet/CarpetLib/src/defs.hh:144 . In order to see how we get to that point, I am listing here the files and line numbers corresponding to points 4 to 11 in the backtrace (points 12 and 13 are not relevant I think):<br>
><br>
> 4. Cactus/arrangements/Carpet/CarpetIOHDF5/src/OutputSlice.cc:1087<br>
> 5. Cactus/arrangements/Carpet/CarpetIOHDF5/src/OutputSlice.cc:562<br>
> 6. Cactus/arrangements/Carpet/CarpetIOHDF5/src/OutputSlice.cc:469<br>
> 7. Cactus/arrangements/Carpet/CarpetIOHDF5/src/OutputSlice.cc:356<br>
> 8. Cactus/arrangements/Carpet/Carpet/src/OutputGH.cc:51<br>
> 9. Cactus/arrangements/Carpet/Carpet/src/Evolve.cc:730<br>
> 10. Cactus/arrangements/Carpet/Carpet/src/Evolve.cc:703<br>
> 11. Cactus/src/main/flesh.cc:88<br>
><br>
> Visually, the 1D and 2D output does not show any obviously wrong features, so I have no clue about what is going on. Do you have any ideas?<br>
><br>
> I am also attaching the parameter file I am running with and the optionlist I used to compile. Kindly let me know if I can provide further info and/or attach any other file you may find useful.<br>
><br>
> Thank you very much in advance for your help,<br>
> Lorenzo Ennoggi<br>
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<br>
<br>
<br>
-- <br>
Erik Schnetter <<a href="mailto:schnetter@gmail.com" target="_blank">schnetter@gmail.com</a>><br>
<a href="http://www.perimeterinstitute.ca/personal/eschnetter/" rel="noreferrer" target="_blank">http://www.perimeterinstitute.ca/personal/eschnetter/</a><br>
</blockquote></div>