Re: [Starpu-devel] Applications allowed to do computations in their own cores ?

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Stephanie Even, le Thu 22 Sep 2011 18:58:26 +0200, a écrit :
> But I have discovered that it is not possible
> with StarPU according to page 17 of the manual, § 3.3 "Kernel threads
> started by StarPU" which is flagged as TODO.

Yes, threads outside StarPU tasks are still a TODO.

> (StarPU displays 1200 % CPU. I guess it is only busy waiting).

Yes.

> Is it possible to make StarPU allowing the user to use its own
> parallelism ?

The trunk version of StarPU can already do so, it is called "parallel
tasks". We still need to document it. You will probably want to use
examples/openmp/vector_scal.c as an example: the scal_cpu_func()
codelet starts its own threads, and StarPU has already asked the OS to
restrict their scheduling on the proper cores. We however have to set
single_combined_worker to 1 because most OpenMP environment don't permit
concurrent parallel sections, MKL will probably need that too.

Samuel