MKL PARDISO: floating-point error with zero pivots ...

MKL PARDISO: floating-point error with zero pivots ...

Hi,

we have detected problems with the current version of the PARDISO solver.

(MKL vers. 2017.4.210, Windows x64 architecture, static linking, Microsoft VS 2015).

PARDISO produces a floating-point error in phase 22, if the coefficient matrix of a FEM analysis has zero pivots.

Another problem is, that PARDISO doesn’t return the correct line number of the first pivot element (iparm[29]).

In former versions PARDISO worked well in this regard.

I have attached some screen shots and a code sample to demonstrate the above problems.

Thank you for your answer.

Regards

Dr. Guenter Kaufels, InfoGraph GmbH, Aachen, Germany

 

AttachmentSize
Downloadapplication/pdf Attachment.pdf2.17 MB
6 posts / 0 new
Last post
For more complete information about compiler optimizations, see our Optimization Notice.

Hi Guenter!  

Thanks for report. Actually, this is not MKL ver. 2017.4.210 but this is MKL 2017 u3 ( pls check the mkl_version.h).  
But nevertheless, at the first glance, the exception could not be generated. We will investigate the case. 
1.    On my side, I see exception is generated with MKL 2017 u3 (latest) and with MKL 11.3.4 either. Win64, static linking, VS 2013, AVX2 code.
2.    Meantime, I checked the second problem you reported “iparm[29]” and see the same results with both of these versions:  

Major version:           2017
Minor version:           0
Update version:          3
Product status:          Product
Build:                   20170413
Platform:                Intel(R) 64 architecture
Processor optimization:  Intel(R) Advanced Vector Extensions 2 (Intel(R) AVX2) enabled processors
================================================================

ERROR during the triangulation of the system: -4
Line No. 9

***************************************************************************************************
***************************************************************************************************
***************************************************************************************************

Major version:           11
Minor version:           3
Update version:          4
Product status:          Product
Build:                   20160823
Platform:                Intel(R) 64 architecture
Processor optimization:  Intel(R) Advanced Vector Extensions 2 (Intel(R) AVX2) enabled processors
=================================================================

ERROR during the triangulation of the system: -4
Line No. 9

Hi Gennady!

Thank's for your quick response!

You are right, the MKL version that we use is 2017 update 3:

#define __INTEL_MKL_BUILD_DATE 20170413

#define __INTEL_MKL__ 2017

#define __INTEL_MKL_MINOR__ 0

#define __INTEL_MKL_UPDATE__ 3

#define INTEL_MKL_VERSION 20170003

The problem with the reported line numbers from “iparm[29]” seems to be a little bit complicated.

I have tested the behaviour and I found that it depends from the number of threads.

In the attachment you find a new test code with a matrix that returns the correct line number 30 for num_threads=1.

For num_threads=2  PARDISO returns the incorrect line number 1.

I hope, that you can now check the problem.

Nice weekend and best regards,  Guenter

 

 

Attachments: 

AttachmentSize
Downloadtext/x-c++src PardisoTest.cpp10 KB

Hi Guenter,

Yes, i reproduced the similar behavior with the latest update 3 too on my side. The issue will be escalated and we will keep you informed with any updates. Thanks again for the case.

with regards

and it seems this is some sort of regression issue, because of MKL 11.3.4 returns the identical results.

Hi Gennady!

Thank you for dealing with the problem so quickly.
I'm looking forward to your solution of the problem.

Regards, Guenter

 

Leave a Comment

Please sign in to add a comment. Not a member? Join today