[Rd] mcmapply Core Usage
simon.urbanek at r-project.org
Fri May 30 03:29:31 CEST 2014
On May 29, 2014, at 8:04 PM, Henric Winell <nilsson.henric at gmail.com> wrote:
> Simon Urbanek skrev 2014-05-29 15:06:
>> yes, that is a bug, now fixed.
> Thanks for fixing it.
> This problem was independently reported some time ago (https://bugs.r-project.org/bugzilla/show_bug.cgi?id=15016) and I believe that it can now be closed.
Ah, thanks, done,
>> On May 29, 2014, at 2:00 AM, Dario Strbenac <dstr7320 at uni.sydney.edu.au> wrote:
>>> I have a minimal example that shows a problem I'm having with parallel processing.
>>> mcmapply(function(x, y)
>>> }, as.list(1:10), as.list(10:1), mc.cores = 16, SIMPLIFY = FALSE)
>>> I see "Running" printed once every ten seconds. I read the documentation for mcmapply, but I don't understand why it wouldn't print all ten output statements almost at once, then wait for about ten seconds, then return to the prompt. Is it documented in another location ?
>>> My problem is that I have a section of code that takes a long time, which I have replaced with Sys.sleep in the above example, but when I look at the output of top, I only see 1 CPU being used. The computer has 16 processors.
>>> R version 3.1.0 (2014-04-10)
>>> Platform: x86_64-pc-linux-gnu (64-bit)
>>>  LC_CTYPE=en_AU.UTF-8 LC_NUMERIC=C
>>>  LC_TIME=en_AU.UTF-8 LC_COLLATE=en_AU.UTF-8
>>>  LC_MONETARY=en_AU.UTF-8 LC_MESSAGES=en_AU.UTF-8
>>>  LC_PAPER=en_AU.UTF-8 LC_NAME=C
>>>  LC_ADDRESS=C LC_TELEPHONE=C
>>>  LC_MEASUREMENT=en_AU.UTF-8 LC_IDENTIFICATION=C
>>> attached base packages:
>>>  parallel stats graphics grDevices utils datasets methods
>>>  base
>>> loaded via a namespace (and not attached):
>>>  tools_3.1.0
>>> Dario Strbenac
>>> PhD Student
>>> University of Sydney
>>> Camperdown NSW 2050
>>> R-devel at r-project.org mailing list
>> R-devel at r-project.org mailing list
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