undesired forking from either doMC, foreach or multicore
Hi For what it's worth, I got a bunch of Break on __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__() to debug when using multicore (with or without foreach) on my dual core MacBook. I was running R in a terminal as required for safe use of multicore, but as far as I can tell, the problem occurred whenever I had used the quartz device for plotting in the same session. No plots or plots using the X11 device have so far not resulted in the problem. See also this post: https://stat.ethz.ch/pipermail/r-sig-mac/2009-August/006426.html Best, Niels
On 08/01/11 13.32, Steve Lianoglou wrote:
Hi, On Sat, Jan 8, 2011 at 3:21 PM, Michael Braun<braunm at mit.edu> wrote:
Thanks for the suggestion. I am not calling additional parallelized routines from the threaded functions. However, I am using the threaded version of the Intel MKL BLAS, and there are matrix manipulations in the threaded functions. Even though MKL is supposed to be thread-safe, would it make sense that this is what is causing the problem?
For what it's worth, I'm running R on a very similar system (only 8 cores, 2008 vintage, alas), but I *do* run into this problem occasionally. I don't use (don't have) MKL BLAS, and I'm pretty sure I'm not calling "additional parallelized routines from the threaded functions" either. I don't know how to create a meaningful test case to reproduce this either, as it seems to happen not so frequently (recently, anyway). My solution is the same as yours, which is to kill all "zombie" R processes and just try again. -steve
Niels Richard Hansen Web: www.math.ku.dk/~richard Associate Professor Email: Niels.R.Hansen at math.ku.dk Department of Mathematical Sciences nielsrichardhansen at gmail.com University of Copenhagen Skype: nielsrichardhansen.dk Universitetsparken 5 Phone: +1 510 502 8161 2100 Copenhagen ? Denmark