RFR (XS): 8216316: jdk/jfr/event/gc/detailed/TestPromotionEventWithG1.java fails due to reserved TLAB area too large

[sangheon.kim at oracle.com]

Hi Thomas,

On 1/8/19 4:41 AM, Thomas Schatzl wrote:
> Hi all,
>
>    can I have reviews for this fix to some test options to make the
> TestPromotionEventWithG1 test more stable on the platforms we support?
>
> In particular, depending on hardware, the minimum TLAB size given in
> the test was too small to accomodate the prefetching code C2 emits when
> allocating objects.
>
> The fix is to minimize this buffer by twiddling with prefetching
> amounts, and increasing the minimum tlab size a bit - so that the test
> still fails with the patch for 8212766 not applied.
>
> Thanks go to Goetz from SAP who figured out the values for the
> prefetching so that most supported systems worked.
>
> @Goeth: can you check this fix on your systems too?
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8216316
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8216316/
Looks good.

Thanks,
Sangheon


> Testing:
> Test failing test on various machines in our CI system
>
> Thanks,
>    Thomas
>
>