On Fri, Sep 3, 2010 at 8:01 PM, Simon King <[email protected]> wrote: > Hi David, > > On 4 Sep., 01:53, "Dr. David Kirkby" <[email protected]> wrote: >> Is SAGE_NCPUS used anywhere? > > Well, I was not suggesting to introduce an environment variable that > is used anywhere in Sage except to "tame" my test script. Of course, > if there already is an environment variable that provides what I need, > I'd use it. > >> I think SAGE_NUMBER_THREADS is more useful. > > Sounds good; and actually when I said "number of CPUs", I should have > said "number of threads". How can this number be determined?
The number of threads you can use is roughly limited to the amount of memory you have available to each thread (this is an oversimplification). So you must have a reasonable approximation of the amount of memory each thread you launch will consume to be able to set an upper limit. Linux has a hard limit on this number that is tweakable via /proc but your performance will likely decrease before you hit that limit (it's around 1200) didier > > Best regards, > Simon > > -- > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/sage-support > URL: http://www.sagemath.org > -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
