[Rd] Optimize R: some confusion with Lapack and OpenBlas/openBlas openmp packages.

[arnaud gaboury]

On Thu, Sep 17, 2015 at 11:43 PM, arnaud gaboury
<arnaud.gaboury at gmail.com> wrote:
> I run Fedora 22 R package. It is build with  --with-lapack \
> --with-blas \  --enable-R-shlib \.
>
> As the machine will act as a server with lots of R data computing, I
> try to optimize my R package.
>
> At first, I installed parallel_studio_xe_2016 with a free one year
> licence. Then, I build a package for R with Intel MKL and compiler.
> This took me lots of time as it was my first .rmp build. I finally
> managed to build and run it.
>
> Now, when looking at some blogs about R-RBenchmark.25, I realized that
> there is very few speed difference between Intel BLAS and OpenBlas. I
> am now wondering if such Intel stuff (with its paid licencing) and the
> need to build my own R package is really worth.
>
> Do anyone have some realistic point of view/advice?
>
> Then, in case I gave up with the Intel stuff, I am confused between
> the Lapack package and Openblas one. I know first one will provide
> liblas.so.3 when second one libopenblas.so. Am i right to say I only
> need one blas library and the openBlas one is the one to get? Can I
> use instead the openmp version of openblas, or shall I installed both?
> here again, I am a litle confused.
> As for the liblapack.so.3, I will get it from the Fedora lapack package.
>
> last, what is the correct way to tell R to use these shared libraries,
> after R has been built?

What I have done:
# update-alternatives --install /usr/lib64/libblas.so.3 libblas.so.3
/usr/lib64/libopenblas.so 90
so now:
# update-alternatives --config libblas.so.3
There is 1 program that provides 'libblas.so.3'.

  Selection    Command
-----------------------------------------------
*+ 1           /usr/lib64/libopenblas.so

--------------------------------

As for lappack, I can't see anything about this library in my R
dynamic executable:

% ldd /usr/lib64/R/bin/exec/R
linux-vdso.so.1 (0x00007fffc8de5000)
libR.so => /usr/lib64/R/lib/libR.so (0x00007f69b8d93000)
libgomp.so.1 => /lib64/libgomp.so.1 (0x00007f69b8b70000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f69b8954000)
libc.so.6 => /lib64/libc.so.6 (0x00007f69b8594000)
libblas.so.3 => /lib64/libblas.so.3 (0x00007f69b64ef000)
libgfortran.so.3 => /lib64/libgfortran.so.3 (0x00007f69b61c4000)
libm.so.6 => /lib64/libm.so.6 (0x00007f69b5ebc000)
libquadmath.so.0 => /lib64/libquadmath.so.0 (0x00007f69b5c7c000)
libreadline.so.6 => /lib64/libreadline.so.6 (0x00007f69b5a32000)
libtre.so.5 => /lib64/libtre.so.5 (0x00007f69b5822000)
libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f69b55b1000)
liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f69b538b000)
libbz2.so.1 => /lib64/libbz2.so.1 (0x00007f69b517b000)
libz.so.1 => /lib64/libz.so.1 (0x00007f69b4f64000)
librt.so.1 => /lib64/librt.so.1 (0x00007f69b4d5c000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f69b4b58000)
libicuuc.so.54 => /lib64/libicuuc.so.54 (0x00007f69b47c6000)
libicui18n.so.54 => /lib64/libicui18n.so.54 (0x00007f69b436f000)
/lib64/ld-linux-x86-64.so.2 (0x000055bf4c183000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f69b4157000)
libtinfo.so.5 => /lib64/libtinfo.so.5 (0x00007f69b3f2d000)
libicudata.so.54 => /lib64/libicudata.so.54 (0x00007f69b2501000)
libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007f69b217f000)

-------------------------------------------------------

I guess I have to build with openmp to be able to use it.



>
> Thank you for advices and help.
>
> --



-- 

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