Re: After building Octave with ATLAS - matrix multiplication is still single threaded

[David Parks]

Now that seems obvious in retrospect. :)  Thanks for spotting it.

However, while I fully expected this to get me to the pot of gold at the 
end of the rainbow, it somehow did not. I have rebuilt twice, the second 
time completely starting from newly unzipping octave sources. The config 
script now shows the expected:

...
BLAS libraries:              /usr/local/atlas/lib/libtatlas.so
...
LAPACK libraries:            /usr/local/atlas/lib/libtatlas.so
...

But when I run octave `./run-octave` (from the make directory after 
running `make`, no difference, my matrix multiplication operation is 
still only using one thread.

@louis scott - I saw your previous post on old nabble, found it on 
google a couple days ago, it helped me figure out that I needed to build 
the shared ATLAS libraries once I got my hands dirty in the config script.

So, is there a way in octave to get some indication if the compiled 
version took the right libraries? Or something else obvious I might have 
missed? I did have a standard package install of octave on the system 
before building it myself for the ATLAS functionality, no idea if 
perhaps those libraries are getting mixed in accidentally.

Here are the references to atlas I see in the make output if that's 
interesting:  http://pastebin.com/egfGkv6n

Thanks for the help all!
David


On 5/28/2014 11:12 AM, Dmitry Roshchin wrote:
> On Wednesday 28 May 2014 11:04:20 David Parks wrote:
> > My goal is to have multi-threaded matrix multiplication.
> >
> > 1) To that end I've built ATLAS (shared libraries are good).
> > 2) Built Octave from sorces, linking ATLAS
> >
> > Octave ./configure script shows:
> > |...
> >
> > BLAS libraries:              /usr/local/atlas/lib/libsatlas.so
> > ...
> > LAPACK libraries:            /usr/local/atlas/lib/libsatlas.so
> > ...
> >
> >
> >
> > But this little test in Octave runs single threaded still:
> It's normal:
> http://math-atlas.sourceforge.net/atlas_install/node22.html
>
> > libsatlas.[so,dylib,dll]
> >
> >      : This library contains all serial APIs (serial lapack, serial BLAS),
> >      : and all ATLAS symbols needed to support them.>
> > libtatlas.[so,dylib,dll]
> >
> >      : This library contains all parallel APIs (parallel LAPACK and parallel
> >      : BLAS) and all ATLAS symbols needed to support them.
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/help-octave