[R-SIG-Mac] R not accessing inactive RAM in Leopard
simon.urbanek at r-project.org
Fri Feb 22 18:57:27 CET 2008
contrary to the subject this has nothing to do with R, you are just
making incorrect assumptions about memory types in OS X. Please
consider reading the appropriate documentation:
Inactive pages still need to be paged out when more resident RAM is
requested. Also it is not R who is swapping anyway ...
On Feb 22, 2008, at 12:08 PM, Matthew Keller wrote:
> Hello all,
> I am not certain whether this issue pertains to the Leopard OS or to R
> or some combination. I have been running 64 bit R for the first time
> over the last couple of weeks and so am still learning the ins and
> outs of it. I have 18GB RAM on a 3.0 2008 Mac Pro. My R version is
> posted below.
>> From the "top" command in terminal, I'm showing 5GB of inactive RAM.
>> From the Leopard Activity Monitor page, with regard to inactive
> memory, it says "This information [inactive RAM] is no longer being
> used and has been cached to disk, but it will remain in RAM until
> another application needs the space. Leaving this information in RAM
> is to your advantage if you (or a client of your computer) come back
> to it later."
> However, yesterday R accessed 12GB RAM and then started swapping to
> hard drive (the pageouts went from 0 to 327000), all the while that
> 5GB inactive RAM just sat right where it was. I had been expecting R
> to access this inactive RAM once it ran out of free RAM rather than
> swapping to hard drive. I can't believe that the Leopard OS is this
> inefficient with memory allocation, so I'm guessing I'm not
> understanding something. Does anyone understand why this might be
> happening, and/or have any ideas about how to get R to access that
> inactive memory?
> Thank you!
> R version 2.6.2 alpha (2008-01-29 r44238)
> attached base packages:
>  stats graphics grDevices utils datasets methods base
> loaded via a namespace (and not attached):
>  tools_2.6.2
>  "i386-apple-darwin9.1.0"
>  "i386"
>  "darwin9.1.0"
>  "i386, darwin9.1.0"
>  "alpha"
>  "2"
>  "6.2"
>  "2008"
>  "01"
>  "29"
> $`svn rev`
>  "44238"
>  "R"
>  "R version 2.6.2 alpha (2008-01-29 r44238)"
> Matthew C Keller
> Asst. Professor of Psychology
> University of Colorado at Boulder
> R-SIG-Mac mailing list
> R-SIG-Mac at stat.math.ethz.ch
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