RFR (XS): 8129977: TestSummarizeRSetStats.java fails: Incorrect amount of per-period RSet summaries at the end

[Tom Benson]

Looks good to me.
Tom

On 7/1/2015 8:18 AM, Thomas Schatzl wrote:
> Hi all,
>
>    can I have reviews for the following tiny change that fixes the test
> TestSummarizeRSetStats on machines with a "small" amount of available
> physical memory?
>
> The problem is that when run on machines with little memory, it issues
> two young-only garbage collections instead of one.
>
> The problem is that the test does not fix the initial heap size, which
> is calculated according to available memory. This causes an additional
> young GC after the first one induced by the test, messing up the
> expected amount of log messages.
>
> The reported behavior can be reproduced locally by either manually
> setting -Xms to a significantly lower value than -Xmx (like 12m) or
> setting MaxRAM to the same size as the machine's total physical memory
> (512m - which results in a too small initial heap size of 10M, causing
> this exact error).
>
> After forcing -Xms to -Xmx in the test, it is good again regardless of
> other options.
>
> Thanks to StefanJ for observing the issue with automatic heap sizing on
> the same machine for JDK-8129590 and getting me on the right track.
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8129977
>
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8129977/webrev/
>
> Testing:
> jprt
>
> Thanks,
>    Thomas
>
>