# Openmp: "'mul' has no providers"

**URL:** <https://pyfr.discourse.group/t/openmp-mul-has-no-providers/154>\
**Category:** General\
**Created:** [5 May 2017 16:50 UTC](https://pyfr.discourse.group/t/openmp-mul-has-no-providers/154 "2017-05-05T16:50:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Frank\_Muldoon](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Frank\_Muldoon](https://pyfr.discourse.group/u/Frank_Muldoon)\
**Post date:** [5 May 2017 16:50 UTC](https://pyfr.discourse.group/t/openmp-mul-has-no-providers/154/1 "2017-05-05T16:50:22Z")

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Hello all,

When launching PyFR (`pyfr run -b openmp -p periodic-hills.pyfrm periodic-hills.ini`) it dies with error:

```auto
KeyError: "'mul' has no providers"

```

would anyone have any ideas what the source of this message might be?

Cheers,  
Frank

[periodic-hills.ini](https://pyfr.discourse.group/uploads/short-url/aI64LDtuqqaLNxHMW9M00639xi3.ini) (1.21 KB)

[periodic-hills.msh](https://pyfr.discourse.group/uploads/short-url/vJRyXXJxuFsXtAYlTGIqdFG7a1C.msh) (20.4 KB)

---

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**Author:** ![fdw](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@fdw](https://pyfr.discourse.group/u/fdw)\
**Post date:** [5 May 2017 18:33 UTC](https://pyfr.discourse.group/t/openmp-mul-has-no-providers/154/2 "2017-05-05T18:33:36Z")

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Hi Frank,

It appears as if you are not providing PyFR with a BLAS library (see the  
documentation for the cblas key under the [backend-openmp] section). I  
would recommend OpenBLAS or MKL.

Alternatively, you can get PyFR to continue to use GiMMiK (which is  
really designed for small and sparse matrices) for the larger matrices  
by setting gimmik-max-nnz = \<large number\>. This may result in  
increased startup times and reduced performance compared with a BLAS  
library.

Regards, Freddie.

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<div class="post-metadata">

**Author:** ![111](https://avatars.discourse-cdn.com/v4/letter/1/0ea827/32.png) [@111](https://pyfr.discourse.group/u/111)\
**Post date:** [6 May 2017 06:21 UTC](https://pyfr.discourse.group/t/openmp-mul-has-no-providers/154/3 "2017-05-06T06:21:31Z")

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Hello Freddie,

Thanks, adding the direct path to the BLAS library worked. The 2D example cases ran OK without any BLAS library or changing gimmik-max-nnz. Probably the default value of gimmik-max-nnz is such that GiMMiK was used instead of BLAS.

Cheers,  
Frank