Intel® oneAPI Math Kernel Library
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GGEV only use one thread

psantos
Beginner
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Hello to everyone,

I have a large program that uses some MKL functions to solve linear systems and eigenproblems. I'm using MKL parallel (/Qmkl:parallel). In almost all the functions calls I can see more that one thread being used. However, GGEV is only using one thread. I'm using the FORTRAN 95 interface of this function.

I'm running FORTRAN Composer XE Update 10 under VS2010 and MKL 10.3 Update 10.

Am I missing something? Thank you in advance for all the help.

Gratefully,

Pedro Santos
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5 Replies
Gennady_F_Intel
Moderator
327 Views
Pedro, what are theorder of the input matrices you are trying to solve?
Aleksandr_Z_Intel
327 Views
Pedro,

Which precision of GGEV have being used: z,c,d or s?

Andhow did youverifyonly one thread being used?
psantos
Beginner
327 Views
Hello,

I'm using the double precision real version. At first I've notice this issue in the task manager, simply by observing CPU usage of my program. After discovered this issue, I've made a concurrency test in VTune Amplifier XE to confirm. And I confirmed that only the Main thread is working. There are other three threads (OMP worker thread) that are running, but they are only using residual CPU time. In attachment, I placed a screenshot of the concurrency test. The order of the matrix in this particular test is 500 (usual values are between 160 and 720).

Thank you very much for your help.

Gratefully,

Pedro Santos


Aleksandr_Z_Intel
327 Views
Dear Pedro,
Only complex (cggev/zggev) ?GGEV routines support parallelism at the moment. You can see it in Users's Guideshttp://software.intel.com/en-us/articles/intel-math-kernel-library-documentation/,section Threaded Functions and Problems.
psantos
Beginner
327 Views
Dear Aleksandr Zotkevich,

Thank you very much. I was completely unaware of it. That explains my issue. Do you know when parallelism will be available in dggev?

Gratefully,

Pedro Santos
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