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MOZ
Beginner
493 Views

User error or bug in p?geevx ?

Dear MKL Community,

I have encountered a problem while converting C code that uses LAPACK into code that will use ScaLAPACK. I need to find the right eigenvectors of a non-symmetric real matrix and both sets of eigenvectors (along with eigenvalues) of a non-symmetric, non-hermitian complex matrix.

It is tempting to jump to the conclusion that there is a bug in the relatively newly released p?geevx routines. But I realize that it probably is more likely that I misunderstood the documentation and am sending one or more incorrect parameters to routines or mis-initializing arrays.

I would greatly appreciate it if a more experienced user could take a look at my code to help me find the problem (or problems).

As part of the process of debugging, I stripped the code to more-or-less the bare minimum needed to produce the undesirable behavior. I am posting the real version as pdtest.c and the complex version as pztest.c. The compiler switches I used to compile the code are provided in comments at the beginning of these files.

I am compiling using the gnu C compiler on Ubuntu 16.04 LTS. I have tried both 2020 releases of Intel MKL. I'm using the 2019.7.217 version of the Intel MPI.

The pdtest.c code appears to work with matrix size=12. Example output is provided in the file output01.txt. However, with size=14, the application aborts with calls to MPI_Abort (as seen in output02.txt).

The pztest.c code appears to get stuck in an endless loop, never returning from the call to pzgeevx.  (By never I mean about an hour.) Example output is provided in output03.txt. It may be helpful to know that top shows 100% CPU usage by the processes (see top-output.txt).

Thank you in advance for your help with this problem!

Yours sincerely,

Matthew

 

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4 Replies
Khang_N_Intel
Employee
269 Views

Error confirmed with oneMKL 2021.2. Escalated!


Khang_N_Intel
Employee
239 Views

Hi Mathew,

The problem was in the compiler.

This issue is fixed in the next release of oneMKL, 2021.4.

Best,

Khang


MOZ
Beginner
208 Views

Dear Khang,

 

This is good news. I'm looking forward to the release of 2021.4, then!

 

Yours sincerely,
Matthew

Khang_N_Intel
Employee
164 Views

Hi Mathew,

oneMKL 2021.4 will be released sometime in September this year, unless there are some kinds of delay.

Khang


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