[9] RFR(S): 8066143 [TESTBUG] : New tests in gc/survivorAlignment/ fails

Jon Masamitsu jon.masamitsu at oracle.com
Thu Dec 4 18:41:09 UTC 2014


On 12/04/2014 08:40 AM, Filipp Zhinkin wrote:
> Hi all,
>
> please review the fix for 8066143.
>
> Issue:
> - newly developed tests on survivor alignment failed w/ client VM and 
> MaxRAMFraction=8;
> - test on the command line option fails w/ +IgnoreUnrecognizedVMOptions.
>
> Root cause:
> - gc/survivorAlignment tests verifies that objects promoted to 
> survivor space
>   occupies some specific amount of space depending on 
> SurvivorAlignmentInBytes values.
>   To make sure that there will be enough space to fit all these objects,
>   tests specify [Max]NewSize values. In some cases (like Client VM and 
> MaxRAMFraction=8)
>   initial heap sizecould be smaller then specified NewSize and it will 
> be resized,
>   thus survivor space usage in some cases may be less then expected,
>   just because its size is too small.
>
> - command line option test checks that SurvivorAlignmentInBytes is 
> experimental option
>   and expects that JVM startup willfail w/o 
> +UnlockExperimentalVMOptions specified
>   on the command line, but a set of command line options used in the 
> test may also
>   contain +IgnoreUnrecognizedVMOptions specified during a test run and 
> as a result
>   JVM startup won't fail.
>
> Proposed fix:
> - for all gc/survivirAlignment tests specify InitialHeapSize;

My first thought would have been to specify MaxHeapSize
rather than InitialHeapSize.  There will be a default max heap
size calculated for the platform and specifying InitialHeapSize
will affect the calculated max heap size but that could result
in an unexpectedly small old gen which might have unforeseen
consequences.

Was there a specific reason for choosing InitialHeapSize?

Jon

> - update command line test to use @require tag in order to avoid 
> incompatible options.
>
> Bug id: https://bugs.openjdk.java.net/browse/JDK-8066143
> Webrev: http://cr.openjdk.java.net/~fzhinkin/8066143/webrev.00/
> Testing: manual & automated
>
> Best regards,
> Filipp.



More information about the hotspot-gc-dev mailing list