[Vm-dev] 32bit clean VM work.

John M McIntosh johnmci at smalltalkconsulting.com
Tue Jun 12 07:12:16 UTC 2007

> The good news is that everything works fine on both platforms, even
> when I set the base of heap memory to just below 2MB as John suggested
> for testing.

Well I assume you mean 2GB for 32bit systems, but for 64bit you need  
to get up to the 0x8000000000000000 boundary.

> The bad news is that I cannot get it to fail. My 32-bit system is
> an older 2.4 Linux kernel, which refuses to mmap things at the
> requested locations and therefore does not have a problem.

In all the crash cases we see the stack context go over the 2gb  
boundary expressed as negative values
in the the VM stack traces. Since we know the for() loop in  
incCompMove trashs memory when you walk an object move over
the 2GB boundary what you really need is to confirm the image works  
fine when it starts under 2gb, and ends over 2gb.

That and that really big number for 64bit systems.

John M. McIntosh <johnmci at smalltalkconsulting.com>
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com

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