JDK-4435069 : Hotspot on linux is restricted to a 2GB heap
using Java on linux the maximum amount of memory you can use is -mx1960m,
ie you cannot use a 2GB Java heap. Ie Java -mx2000m -version will display
an error message about lack of heap space
Part of the problem is that linux has previously had restrictions with pthreads
using a 2GB heap even though the stack space per process is 'unlimited'
Currently on Linux, process stack is allocated at 0xC0000000 (3G) and grows
downwards, heap and other memory allocation grows upwards from 0x40000000 (1G).
Stack and heap share this 2G memory address space, which means one cannot have
2G heap on current Linux.
However, the whole thing could change in 64-bit Linux. We don't support 64-bit
Linux, for now.