Arithmetic without limitations?

Vincent Lefevre vincent at
Thu Feb 11 15:07:57 CET 2010

On 2010-02-11 14:43:52 +0100, Paul Zimmermann wrote:
> > Besides, one will need lots of swap space for computing with large
> > numbers.  That's the natural way; You need to compute with a huge data
> > set?  Configure a huge swap area!  4 Gb (which I take as 4 gibibyte) is
> > not good for huge computations, and really strangely small for a machine
> > with 16 gibibyte RAM.

But note that one may want to share machines provided by a lab,
so that one doesn't have a root access (and even though there may
be more swap, it may not be sufficient for some particular user).
However, I'd rather see the inability of adding swap space without
root access as a deficiency of the OS.

> Agreed. I have asked for more swap on that machine. If/when I get
> more swap, I will redo some experiments and report my results here.

You could also try with a memory-mapped file.

Vincent Lefèvre <vincent at> - Web: <>
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Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)

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