[re-adding the bug in CC] Le mercredi 12 février 2014 à 18:19 +0100, Julian Taylor a écrit : > On Wed, Feb 12, 2014 at 6:09 PM, Sébastien Villemot > <sebast...@debian.org> wrote: > Control: tags -1 + upstream > Control: forwarded -1 > https://github.com/xianyi/OpenBLAS/issues/294 > > Le mardi 04 février 2014 à 22:58 +0100, Julian Taylor a > écrit : > > On 04.02.2014 22:52, Sébastien Villemot wrote: > > > Le mardi 04 février 2014 à 22:42 +0100, Julian Taylor a > écrit : > > > > > >> it will deadlock eating all cpu in gomp at the end. > > >> This is the typical failure pattern caused by forks > combined with gnu > > >> openmp (see > https://github.com/xianyi/OpenBLAS/issues/294) > > >> > > >> But the weird part is this testsuite does not fork at > all, so it might > > >> be a different issue. > > >> It did not occur when openblas was still using pthreads. > > > My understanding of the issue is that Python violates the > POSIX API when > forking, and that GCC does not handle that case as well as > some > proprietary compilers. A proposal to change the behavior of > GCC has been > posted at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60035 > > Until GCC is modified (if it is ever), the OpenBLAS maintainer > is trying > to implement a solution at its level (see the github issue at > the top of > this message). > > Julian: does that seem an accurate summary of the situation to > you? > > > no, too my knowledge python forks correctly, fork without execve is > allowed. > gnu openmp simply does not support this type of forking. > R seems to fork in the same way see > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=684344#35 > > > The weird thing in the scipy test case is that no forking is done. > > This could be an bug in openmp itself or scipy corrupting some memory > as I don't see openblas doing anything weird when using openmp.
So we don't even know at this stage if the present bug is a bug in GCC, scipy or openmp. It would help if you could clarify this. -- .''`. Sébastien Villemot : :' : Debian Developer `. `' http://www.dynare.org/sebastien `- GPG Key: 4096R/381A7594
signature.asc
Description: This is a digitally signed message part
-- debian-science-maintainers mailing list debian-science-maintainers@lists.alioth.debian.org http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/debian-science-maintainers
