I will try to talk to my team to fork it for more investigation from your side.
However, this is the story. We have a C package which uses a STARPU runtime system (http://starpu.gforge.inria.fr/doc/starpu.pdf) to facility the parallelization through a set of task-based parallel algorithms. Once you execute Your program StarPU created several threads to parallelize your tasks based on a specific scheduling mechanism. In the case of R, R is used only one process and if I used the default behavior without any modification, all the StarPU threads are using the same physical core which is used by the default R process. We added A simple modification which helps to well spawn the threads to the other available physical cores by disabling the KMP_AFFINITY (Sys.setenv(KMP_AFFINITY= "disabled")). However, Even the performance is improved, the R package is about 5X slow up compared to the C version. The difference we found that In case of R different threads is controlled by R which means that we can see from top Command that R is using n threads on n cores. In the case of C package, StarPU is using these threads. One more difference from htop command that the virtual memory usage of the R package is doubled which we cannot Understand or even know if it is related to the performance issue or not --Sameh On 5/10/19, 6:12 PM, "Iñaki Ucar" <iu...@fedoraproject.org> wrote: On Fri, 10 May 2019 at 17:06, Sameh M. Abdulah <sameh.abdu...@kaust.edu.sa> wrote: > > Actually not yet. It is on Github but in a private repo. If it helps I can fork it for public access for now. Providing the code always improves your chances of getting help. Otherwise, the information is probably too limited. Iñaki ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel
