[Pw_forum] Off-topic: parallel compilation

[Paolo Giannozzi]

IMHO the most likely reason for the crash is insufficient memory,
not insufficient size of 32-bit integers. A few occurrences of the
latter have been encountered and fixed in the past, but only on
very large cells

P.

On Sun, 2014-05-18 at 11:10 -0300, Marcos Veríssimo Alves wrote:
> Hi all,
> 
> 
> This is a bit off-topic, but I'm sure there will be many knowledgeable
> people around. It's related to the parallel compilation of QE.
> 
> 
> I'm trying to run HSE calculations for a 71-atom silicene sheet, using
> Espresso compiled with ifort (composerxe), mpich2 and intel mkl
> included in this version of the compiler. Mpich 2 is compiled using
> gcc/ifort. 
> 
> 
> All goes well in the scf part until it gets to the hybrid functional
> calculation. Then it crashes with an mpi error (Bad termination, code
> 9) which the mpi faq says is usually due to the fact that there is a
> segmentation fault in the code, not in mpi.  They also state that this
> is usually a segmentation fault. 
> 
> 
> I wonder if anyone has run HSE calculations for systems as large as
> this, and if they have run into this problem.
> 
> 
> One possibility that came to my mind is that, if this is a
> segmentation fault, maybe 4-byte integers are not large enough to
> address all the indexes of the arrays allocated in the hybrid
> functional part of the calculation. I tried to compile QE with 8-byte
> integers but I get an mpi error, which I suppose is due to integers
> being compiled with 4-byte integers on the C side of the compilation.
> 
> 
> So, I have two questions:
> 
> 
> 1) Is there any way of compiling Mpich 2 with 8-byte integers using
> gcc?
> 
> 
> 2) If the parallel part were carried out with OpenMP instead of Mpich
> (I have 32 cores in the same node of the computer I'm running the
> calculation), perhaps this could be a workaround for this problem. Is
> it possible to compile QE in parallel mode using only OpenMP and MKL?
> If yes, what options would need to be set for either configure or
> make.sys directly? Configure already detects the mpi environment, and
> sets make.sys to compile QE using it.
> 
> 
> Any help would be greatly appreciated, and I would gladly supply the
> input file along with the pseudo I am using (from the QE database) if
> the developers would like to run tests on it.
> 
> 
> Best regards,
> 
> 
> Marcos
> 
> 
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-- 
Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222