[squeak-dev] Re: 64-bit images

David T. Lewis lewis at mail.msen.com
Fri Nov 9 15:22:50 UTC 2012


On Fri, Nov 09, 2012 at 01:43:15PM +0100, Bert Freudenberg wrote:
> How long does a full GC take for, say, an 8 GB image with a gazillion of small objects?
> 
> - Bert -

Sorry Bert, a gazillion requires the 128-bit object format ;)

My totally unscientific observation is that growing the object memory by
filling it with large objects has no noticeable impact on GC performance.
I don't have any measurements to offer, but I think we will find that
GC performance will degrade as a (non linear) function of number of
objects, and size of the objects will have no impact.

> 
> On 2012-11-09, at 13:10, "Andreas.Raab" <andreas.raab at gmx.de> wrote:
> 
> > Hi David -
> > 
> > This is great, and just in time! I wanted to play around with Squeak on my
> > new z820 development workstation featuring some 256GB of Memory (heh, heh)
> > and was wondering where I could find the right Image/VM pair. Thanks for the
> > post!
> > 
> > Cheers,
> >  - Andreas

Cool! Please let us know how large an image you are able to create.

I'm not sure if those VMs have large file support enabled (very likely
not), so you might need to recompile if you want to save your 255GB image
file to disk.

Dave


> > 
> > 
> > David T. Lewis wrote
> >> The purpose of this change to the SystemReporter is to allow it to
> >> identify the image format and word size (64-bit or 32-bit) of the image
> >> file that is currently being run. An example SystemReporter window from
> >> a 64-bit image is attached.
> >> 
> >> A 64-bit version of the trunk image can be found here:
> >>  http://box3.squeak.org/job/Squeak%2064-bit%20image/
> >> 
> >> A 64-bit image is normally created directly from the normal 32-bit image
> >> using a SystemTracer. This Smalltalk script illustrates how it is done:
> >>  http://box3.squeak.org/job/Squeak%2064-bit%20image/ws/TraceTo64.st
> >> 
> >> To run a 64-bit image on Linux, go to http://squeakvm.org/unix/ and
> >> install
> >> both the "4.10.2.2614 Unix VM" and the "4.10.2.2614 Unix VM for 64-bit
> >> images".
> >> The /usr/local/bin/squeak script will then invoke the right VM to run
> >> your image, either 32- or 64-bit.
> >> 
> >> If you prefer to compile your VM from source, use the source tarball
> >> from http://squeakvm.org/unix/ and run the platforms/unix/cmake/configure
> >> script with the "--image64" option to build a VM for running 64-bit
> >> images. Unofficial and unsupported "bleeding edge" tarballs can also be
> >> found at http://box3.squeak.org/job/InterpreterVM/
> >> 
> >> Cog VMs are not currently able to run the 64-bit image, although they
> >> certainly will do so in the future. For now, a 64-bit image on a standard
> >> interpreter VM will be much slower than the "same" 32-bit image on Cog,
> >> but will have greater address space and an ability to reach a much larger
> >> total image size.
> >> 
> >> Dave
> 


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