RFR: Add humongous regions support to partial GC

[Zhengyu Gu]

Do you really need _humongous_obj_array? should is_humongous() enough to 
indicate that?

Thanks,

-Zhengyu

On 03/16/2017 09:10 AM, Roman Kennke wrote:
> This adds support for humongous regions as root regions in partial GC.
>
> I extended the ShenandoahHeapRegion::oop_iterate() to iterate over a
> subset of a humongous object array (bounded by the region). This way we
> avoid scanning the whole humongous object if the matrix only gives us a
> single region as root.
>
> Tested using gc-bench/arrayfragger (which crashed before).
>
> http://cr.openjdk.java.net/~rkennke/partial-humongous/webrev.00/
> <http://cr.openjdk.java.net/%7Erkennke/partial-humongous/webrev.00/>
>
> Roman
>
>