Thanks for all the help. It was the swap file size that was causing
the problem. I did not realise that the swap file had such a limited
size.
Ubuntu makes it very small by default so I installed it again using
custom setting for the partitions.
I will write a step by step of how to get j64 working on the mac
hopefully by the weekend.


On 12/9/08, Gilles Kirouac <[EMAIL PROTECTED]> wrote:
>  You can get the exact amount of the maximum virtual address space (VAS)
> using command  ulimit -v  at the shell.
>
>  The result is likely related to the size of the available swap space
> (file or partition) set when VMWare installed the virtual machine.
>
>  ~ Gilles
>
> ---------- Original Message -----------
> From: "Eric Iverson" <[EMAIL PROTECTED]>
> To: "Programming forum" <[email protected]>
> Sent: Mon, 8 Dec 2008 22:02:07 -0500
> Subject: Re: [Jprogramming] Large mapped files and VAS again
>
>> Forget about mapped files for a bit. What you need to figure out is
>> what to do to get   newname=: i. bigsize to work (that is, not give
>> out of memory).
>>
>> You need to make your page file big enough and any limits on memory
>> allocation big enough to allow that sentence to run. Your
>> configuration is complicated so this may take a bit of digging. You
>> need to dig into unbuntu, vmware, osx. There are likely required
>> steps at every level.
>>
>> It might be interesting to first determine what the current limit
>> is. Write a loop that does something like:
>>
>>  erase 'newname'
>>  newname=: i. bigsize
>>  bigsize=: bigsize + more
>>
>> When you get the out of memory error, bigsize will tell you how much
>> the layers of OS allow you to allocate. Then you can start the
>> search of how to increase that limit in the OS. This is an issue of
>> the OS, not J.
>>
>> On Mon, Dec 8, 2008 at 4:32 PM, Matthew Brand
>> <[EMAIL PROTECTED]>wrote:
>>
>> > Hi Eric,
>> >
>> > On Mon, Dec 8, 2008 at 2:58 PM, Eric Iverson <[EMAIL PROTECTED]>
>> > wrote:
>> > > RAM is not the limit. THE OS makes RAM essentialy invisible to
>> > applications.
>> > > Actively and randomly using an allocation much larger than RAM will
>> > > work,
>> > > but because of swapping between page file space and RAM space
>> > > performance
>> > > will be much slower than if it fit into RAM.
>> > >
>> > > We have made some progress on your problem. We now know that it has
>> > > absolutely nothing to do with mapped files. I think you will see this
>> > when
>> > > you realize that your expression
>> > >  newname =: i. bigsize
>> > > fails with an out of memory error.
>> > >
>> >
>> > I agree, the mapped files are working perfectly.
>> >
>> > > This means the OS has refused to allocate this amount of memory. This
>> > > allocation has nothing to do with file mapping. This memory would be
>> > > be
>> > > backed by the page file. The OS can also have limits on the largest
>> > > allocation it will allow. This depends on the OS. Are you running
>> > windows?
>> > > You need to make sure that your page file (settings...) is large
>> > > enough
>> > for
>> > > these kinds of allocations.
>> >
>> > I am using Ubunto 64-bit as a virtual machine in VMWare Fusion on OSX
>> > 10.5.5 with 2Gb RAM on a MacBook Pro.
>> >
>> > >
>> > > That said, you may not want to populate your mapped file with J
>> > expressions
>> > > that require being first created entirely in page file space.
>> > >
>> > > Again, I suggest that you do the labs, if you have not already done
>> > > so.
>> > >
>> >
>> > I have looked at the two labs and cannot find any examples of how to
>> > populate a mapped noun which is larger than the RAM other than
>> > nounname =. tempvariable. In-place amend will suffer equally because I
>> > would have to generate the data and the indices.
>> >
>> > Is there another way to populate the mapped noun?
>> >
>> > > Also, I suggest that you play and experiment, with smaller (say 1 or 2
>> > gig
>> > > size arrays) before scaling up so much.
>> >
>> > I have done lots of testing with small data sets which work and am at
>> > the stage where I need to run on the whole data set. I can do the job
>> > in manageable chucks and get a result out (it is messy and slow but
>> > works), but it would be much neater if the memory management was done
>> > in the background, e.g. with the swap file.
>> >
>> > Thanks,
>> > Matthew.
>> > ----------------------------------------------------------------------
>> > For information about J forums see http://www.jsoftware.com/forums.htm
>> >
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
> ------- End of Original Message -------
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

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