[R-sig-Fedora] Changing the BLAS from openblas on a F32 box

[Gavin Simpson]

Dear list,

What is the recommended incantation on Fedora 32 to swap out the
openblas BLAS that the packaged (rpm) version of R-core installs for
ATLAS?

I'm running into some problems with some big models I want to fit
using the mgcv package, and openblas is apparently not thread safe and
is causing problems.

I have the following installed:

$ dnf list installed | grep ^R
R-core.x86_64                               3.6.3-1.fc32
      @fedora
R-core-devel.x86_64                         3.6.3-1.fc32
      @fedora
$ dnf list installed | grep openblas-R
openblas-Rblas.x86_64                       0.3.9-2.fc32
      @fedora

And i'd like to temporarily switch to the atlas BLAS.

If anyone is interested, the issue Simon Wood reports with openblas
and *mgcv* is:

Issues:

** openblas 0.3.x x<7 is not thread safe if itself compiled for single thread
   use and then called from multiple threads (unlike the reference BLAS, say).
   0.2.20 appears to be OK. For 0.3.x x>6 make USE_THREAD=0 USE_LOCKING=1
   to make openblas ensures thread safety (currently unclear if USE_LOCKING
   will be default from 0.3.7).

and running `mgcv:::blas.thread.test()` (Simon's non-exported function
to test for problems) returns:

> mgcv:::blas.thread.test()
  |                                                                      |   0%
BLAS thread safety problem at iteration 2

On my systems.

Thanks in advance for any suggestions as to how to best swap in/out the BLAS

All the best

Gavin
-- 
Gavin Simpson, PhD [he/him/his]           [t] +1 306 337 8863
• Research Scientist                      [f] +1 306 337 2410
Institute of Environmental               [tw] @ucfagls
  Change & Society                        [w] goo.gl/Zpkdem
University of Regina         [w] www.iecs-uregina.ca
Regina, SK S4S 0A2, Canada               [iD] 0000-0002-9084-8413

• Adjunct Professor, Department of Biology, University of Regina.