RFR (S) 8222186: Shenandoah should not uncommit below minimum heap size

[Zhengyu Gu]

ShenandoahHeap.hpp L#200 : indents

Otherwise, looks good.

-Zhengyu


On 4/9/19 9:55 AM, Aleksey Shipilev wrote:
> RFE:
>    https://bugs.openjdk.java.net/browse/JDK-8222186
> 
> Fix:
>    http://cr.openjdk.java.net/~shade/8222186/webrev.01/
> 
> There is some confusion what -Xms really means. Current code assumes it only means "initial" heap
> size, which allows it to uncommit the heap below -Xms. However, users expect -Xms to mean "minimum
> heap size" to set the low watermark for heap shrinkage. We need to amend Shenandoah to avoid
> uncommitting below that watermark.
> 
> Testing: hotspot_gc_shenandoah (includes new test cases), eyeballing gc logs
>