[OmniOS-discuss] Upgrading Java to OpenJDK8 - any advice?

[Ben Summers]

> On 12 Nov 2015, at 12:08, Jim Klimov <jimklimov at cos.ru> wrote:
> 
> There's a couple cents from me twoo ;)
> 
> Dual-personality (-d32 and -d64) - yes both please. There are small services written in Java mostly for portability rather than scalability. They do not require 4g+ VM space, but would suffer (consume noticeably mkre hist memory) from largish 64-bit pointers all over the stack.

On x64, with heaps under 4GB, Java uses compressed OOPs (object pointers) which only take up 32 bits and use a fancy x86 addressing mode to work just as fast as 64 bit pointers.

They removed 32 bit support from Solaris Java because there didn't seem to be much point. 64 bit didn't take up more memory, and went faster because of the better instruction set.

Of course if you have a 32 bit server, or want to use JNI with 32 bit binaries, that's little consolation.

Ben