Bug#961725: libopenblas-dev: On some cpus, openmp and pthread dead-lock

[Sébastien Villemot]

Hi Dirk,

Le jeudi 28 mai 2020 à 07:07 -0500, Dirk Eddelbuettel a écrit :
> Package: libopenblas-dev
> Version: 0.3.8+ds-1
> Severity: serious

> In short, when libopenblas-dev is installed (as e.g. from r-base-dev as a
> dependency from libblas-dev, liblapack-dev) then
> 
>     libopenblas0-pthread
> 
> is installed first via our depends ranking as libopenblas-pthread-dev comes
> first.
> 
> This has served us well over the years but can exhibit a bug which I for
> example saw with (Ubuntun's) 0.3.8+ds-1 package. Running a simple
> 
>     example(solve)
> 
> in R hangs in an unsuspendable session (ie no Ctrl-C, kill is needed).
> Simplest test is on the command-line via
> 
>     $ Rscript -e 'example(solve)'
> 
> Removing libopenbkas0-pthread and installing libopenblas-openmp-dev helps. As
> does a manual reordering of the alternatives.
> 
> This bug is reproducible on my system with a i7-8700k.

I’ve tried to reproduce it on my i7-8700K, without success. I used a
clean sid chroot (with r-base 4.0.0-3 and openblas 0.3.9+ds-1).
Downgrading to openblas 0.3.8+ds-1 (which is the version against which
you reported the bug) does not change anything.

So it’s not clear that this bug is tied to a specific hardware. At
least, a given CPU model is not a guarantee of reproducibility.

-- 
⢀⣴⠾⠻⢶⣦⠀  Sébastien Villemot
⣾⠁⢠⠒⠀⣿⡁  Debian Developer
⢿⡄⠘⠷⠚⠋⠀  https://sebastien.villemot.name
⠈⠳⣄⠀⠀⠀⠀  https://www.debian.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: This is a digitally signed message part
URL: <http://alioth-lists.debian.net/pipermail/debian-science-maintainers/attachments/20200528/6a39ea6b/attachment.sig>