[R] .Call using multiple cores on linux after R 3.3.3

[Youyi Fong]

Thanks, Jeff! You are absolutely correct. We have OPENBLAS installed in our
environment that causes this.

One way to "fix" it is:

library(RhpcBLASctl)
blas_get_num_procs()
blas_set_num_threads(1)
stopifnot(blas_get_num_procs()==1)



On Sat, Apr 20, 2019 at 9:06 AM Jeff Newmiller <jdnewmil using dcn.davis.ca.us>
wrote:

> My guess would be that you are running with a non-CRAN distribution of R
> like Anaconda or MRAN that has MKL enabled?
>
> On April 19, 2019 10:25:57 AM PDT, Youyi Fong <youyifong using gmail.com> wrote:
> >Hi, I am wondering why it is the case that in R 3.3.3, calling
> >chngpt:chngptm uses only 1 core, but in later releases, e.g. R 3.4.3,
> >it
> >uses multiple cores on linux. The function chngpt:chngptm has a .Call
> >to
> >invoke a C/C++ function that performs bootstrapping. No explicit
> >parallel
> >computing instructions are used.
> >Thanks,
> >Youyi
> >
> >       [[alternative HTML version deleted]]
> >
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