RFR (S): 8152724: Sum of Eden, survivor and old capacity may be larger than heap size

[sangheon.kim at oracle.com]

Hi Thomas,

On 11/29/18 6:26 AM, Thomas Schatzl wrote:
> Hi all,
>
>    can I have reviews for this small change that fixes some bug in
> determining the "correct" number of maximum survivor regions for the
> current GC?
>
> Currently the maximum survivor regions are calculated directly from
> maximum eden size divided by SurvivorRatio. If the eden is large, and
> SurvivorRatio small, this could result in strange log output indicating
> that there is more space in the Java heap available than there
> actually is space :)
>
> Of course this is not true, and in reality the GC would go into an
> evacuation failure before allocating that many regions, but
> nevertheless the output is incorrect.
>
> This change limits the internal max survivor size variable used for
> printing to the amount of free space.
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8152724
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8152724/webrev/
Looks good.

Thanks,
Sangheon


> Testing:
> new test, hs-tier1-3
>
> Thanks,
>    Thomas
>