[Wien] BACKSPACE error in lapwso calculation

[Gavin Abo]

I cannot say for sure, but I would suspect that it is caused by an Intel 
Fortran bug.

Previously, you reported an "end-of-file during read" error [1] with 
intel/2017 [2].  And now, you report "BACKSPACE error", which is another 
file reading error.  Maybe the errors observed in 2016 Update 3 [3] 
haven't entirely been resolved in intel/2017.

Did this error occur when WIEN2k was compiled with -O0?  If not, I 
suggest trying it to see if the error goes away or not.

Version 15 had a BACKSPACE bug in the run-time library (RTL) [4]. So if 
there is a bug, it might come from this library.  Have you tried the 
calculation when WIEN2k was compiled with the dynamic libraries, then 
again with the static libraries using the Intel link advisor [5]?  If 
not, you might give that a try.  I think I encountered a Fortran bug 
once in one of the buggy 12 versions were an error occurred with the 
dynamic libraries, but not with the static ones.  Though, maybe it won't 
help in this case, since it looks like the static and dynamic linking 
uses the same library file (libiomp5.so) [6].

How large is the 1Mn.vectordn_1 file in size?  Do these errors only 
occur with calculations with large files sizes and smaller file size 
calculations using the same sequence of WIEN2k program commands work 
fine?  Perhaps it could be a big data issue if that is the case.  I 
don't remember where I saw it, but I thought I read somewhere that when 
there are clusters and big data are involved, they can be more complex 
to handle.

I don't know if there is a boundary limit on the amount of data 
BACKSPACE can handle [7].  I'm not able to see from the Intel 
documentation whether say a small BLOCKSIZE [8,9] could slow down the 
read, perhaps lead to a time out, and cause such an error. Also, it is 
not clear whether or not it could be caused by a memory leak or memory 
limit from BACKSPACE using n - 1 successive READs [10, 11]. It might 
help to ask the experts about the error on the Intel forum [12].

[1] http://zeus.theochem.tuwien.ac.at/pipermail/wien/2017-March/026101.html
[2] http://zeus.theochem.tuwien.ac.at/pipermail/wien/2017-March/026106.html
[3] 
https://software.intel.com/en-us/articles/read-failure-unformatted-file-io-psxe-16-update-3
[4] 
https://software.intel.com/en-us/forums/intel-visual-fortran-compiler-for-windows/topic/549033
[5] https://software.intel.com/en-us/articles/intel-mkl-link-line-advisor
[6] https://software.intel.com/en-us/node/528514
[7] 
https://software.intel.com/en-us/forums/intel-visual-fortran-compiler-for-windows/topic/274239
[8] 
http://kiwi.atmos.colostate.edu/rr/tidbits/intel/macintel/doc_files/source/extfile/optaps_for/fortran/optaps_prg_io_f.htm
[9] https://software.intel.com/en-us/node/678835
[10] 
https://software.intel.com/en-us/forums/intel-visual-fortran-compiler-for-windows/topic/593848
[11] https://software.intel.com/en-us/node/692589?language=en
[12] 
https://software.intel.com/en-us/forums/intel-fortran-compiler-for-linux-and-mac-os-x

On 3/21/2017 8:46 AM, Md. Fhokrul Islam wrote:
> Hi Prof Blaha and Wien2k users,
>
> I am running a surface supercell calculation with spin-orbit 
> interaction using non-scf
> method.  While LAPW1 worked fine and produced the energy and scf1 
> files correctly,
> LAPWSO failed with BACKSPACE error. Please see the error message 
> below. I have checked
> the get_nloat.f file and while there is a BACKSPACE statement in line 
> 22 but it is not
> obvious to me why there is a problem to execute this line. Somewhere 
> it seems to have
> generated an 'forrtl: Invalid argument' after LAPW1 but not sure 
> why. I am using Wien2k_16
> which I have compiled with intel/2017.
>
>  LAPW1 END
>  LAPW1 END
>  LAPW1 END
>  LAPW1 END
>  LAPW1 END
>  LAPW1 END
>  LAPW1 END
>  LAPW1 END
> forrtl: Invalid argument
> forrtl: severe (23): BACKSPACE error, unit 9, file /scratch/1Mn.vectordn_1
> Image              PC                Routine  Line        Source
> lapwso             0000000001D5AFBC  Unknown   Unknown  Unknown
> lapwso             0000000001D57771  Unknown   Unknown  Unknown
> lapwso             00000000004305D6  get_nloat_       22  get_nloat.f
> lapwso             0000000000419F2F  MAIN__      144  lapwso.F
> lapwso             000000000040442E  Unknown   Unknown  Unknown
> libc-2.23.so       00002AF2B4B9A830  __libc_start_main   Unknown  Unknown
> lapwso             0000000000404329  Unknown   Unknown  Unknown
>
> Any suggestion will be appreciated.
>
> Thanks,
> Fhokrul
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