[Octave-bug-tracker] [bug #61246] matrix inversions give wrong results (inv, lu, mldivide)

[Markus Mützel]

Follow-up Comment #21, bug #61246 (project octave):

There is an un-applied patch in bug #61208 that would probably set the number
of OpenBLAS threads to the actual number of physical cores. But I'm unsure if
it will work before Windows 7.

Octave 7 will be the first version to require Windows 7 or newer. So, we
should probably wait with that change until after the last Octave 6.x
release.

Limiting the number of OpenBLAS threads didn't help for Joohwa Lee anyway. See
comment #13.
So, the bugs that Dmitri and Joohwa are seeing might not be the same.
But IIUC, Dmitri didn't need to limit the number of OpenBLAS threads with a
build from octave.space. The "only" difference was that the performance was
worse when the threads weren't limited.
With Octave from the "official" installer, he got wrong result when he didn't
limit the number of threads...


I also don't really understand the OpenBLAS build system very well. From what
I gather, code specific to *multiple* target CPUs is built when we set
DYNAMIC_ARCH=1. Additionally, there seems to be some common "base" code that
is shared between all architectures. The minimum architecture that is required
to run that common code can be selected with "TARGET=".

My understanding of that might be flawed. From what I gather, we are doing it
right. But obviously, we are missing something...


    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?61246>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/