R devel - Dec 2016 - parallel::detectCores() bug on Raspberry Pi B+

In R 3.3.2 detectCores() in package parallel reports 2 rather than 1 on 
Raspberry Pi B+ running Raspbian. (This report is just 'for the record'.
The model is superseded and I think no longer produced.)  The problem 
seems to be caused by

  grep processor /proc/cpuinfo
processor	: 0
model name	: ARMv6-compatible processor rev 7 (v6l)

(On Raspberry Pi 2 and 3 there is no error because the model name lines are

  model name	: ARMv7 Processor rev 5 (v7l)
  model name	: ARMv7 Processor rev 4 (v7l)
)

On 10/12/16 00:22, Paul Gilbert wrote:
> In R 3.3.2 detectCores() in package parallel reports 2 rather than 1 on
> Raspberry Pi B+ running Raspbian. (This report is just 'for the
record'.
> The model is superseded and I think no longer produced.)  The problem
> seems to be caused by
>
>  grep processor /proc/cpuinfo
> processor    : 0
> model name    : ARMv6-compatible processor rev 7 (v6l)
>
> (On Raspberry Pi 2 and 3 there is no error because the model name lines are
>
>  model name    : ARMv7 Processor rev 5 (v7l)
>  model name    : ARMv7 Processor rev 4 (v7l)
> )
I posted a related bug report to R bugzilla, 
<https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=17213>. The patch 
included in that report is mainly about detecting physical CPUs across 
multiple CPU sockets, but should also fix this issue.

-- 
Mikko Korpela
Department of Geosciences and Geography
University of Helsinki