Changing the BLAS from openblas on a F32 box
FYI, USE_LOCKING=1 has been toggled in Fedora, so the next openblas release (0.3.9-3) will be thread-safe by default.
On Wed, 27 May 2020 at 23:46, I?aki Ucar <iucar at fedoraproject.org> wrote:
On Wed, 27 May 2020 at 23:03, Gavin Simpson <ucfagls at gmail.com> wrote:
Thanks (again) I?aki. There was a typo in my reply above. I should have said: I *can't* answer the question re USE_LOCKING=1.
:)
Those other suggestions are really helpful too; I really didn't understand what the difference was (I'm still not clear what the differences are between say openblas-openmp and openblas-openmp64), but I did get R to pass mgcv's thread safe test with both openblas-openmp and blis-openmp, so I have aliased those options for use too.
Basically, openblas has a number of features that can be enabled or disabled: 64-bit integer support, threading and parallelization of certain parts using openmp (as, e.g., data.table does). With the combination of these features, we end up with many different flavors, and all these are compiled and sub-packaged separately. Usually, you want parallelization at the top level calling a serial version, as mgcv does. Otherwise, you may end up with an "explosion" of threads that is counterproductive. -- I?aki ?car
I?aki ?car