jigsaw startup memory requirements

[Alan Bateman]

On 09/10/2015 22:15, Martin Buchholz wrote:
> Latest jigsaw b83 works well with the temporary hacks we have in place in
> jsr166 CVS, but we do see one jtreg test failure.
>
> Running a modern jdk with only -Xmx2m is pushing it, but you probably don't
> want to arbitrarily increase jdk memory requirements just for jigsaw.
>
> Should be bump up the -Xmx in this test or wait for y'all-dev to reduce
> memory footprint?
>
> util/concurrent/ConcurrentLinkedQueue/RemoveLeak.java
>
As things currently stand then the heap usage at startup is about 800k 
higher than before when all modules are linked in, much less on a small 
runtime (for embedded) that only has a small number of modules linked 
in. There are few things in flight that should reduce this a bit. We 
also need to re-examination once the compact strings work (JEP 254) goes 
into JDK 9.

The other thing is the switch to region based heap with G1. Does 
RemoveLeak pass if you specify -XX:+UseParrallelGC?

-Alan