RFR (S) 8219524: Shenandoah misreports "committed" size in MemoryMXBean

[zgu at redhat.com]

Looks good.

-Zhengyu

On Thu, 2019-02-21 at 11:19 +0100, Aleksey Shipilev wrote:
> Bug:
>   https://bugs.openjdk.java.net/browse/JDK-8219524
> 
> Fix:
>   http://cr.openjdk.java.net/~shade/8219524/webrev.01/
> 
> See the backing story in the bug. Arguably, this is due Shenandoah
> departing from what shared code
> believes GC implementation should be doing, i.e. returning the amount
> of committed memory with
> CollectedHeap::capacity(). Would that be a fair characterization?
> Even so, rewiring Shenandoah to
> match the shared code expectations would require more work, but we
> can plug the current failure with
> this patch meanwhile.
> 
> Testing: hotspot_gc_shenandoah, new check in test
> 
> Thanks,
> -Aleksey
>