[14] 8237632: Shenandoah fails some vmTestbase_nsk_jvmti tests with "Forwardee must point to a heap address"

Aleksey Shipilev shade at redhat.com
Tue Feb 4 19:23:05 UTC 2020

On 2/3/20 9:59 PM, Zhengyu Gu wrote:
> Bug: https://bugs.openjdk.java.net/browse/JDK-8237632
> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8237632/webrev.00/

Uh. It seems to me the cure is worse than the disease:
  1) It rewires sensitive parts of barrier paths, root handling, etc, which requires more thorough
testing, and we are too deep in RDP2 for this;
  2) It effectively disables asserts for anything not in collection set. Which means it disables
most of asserts. The fact that Verifier still works is a small consolation.

I propose to accept this failure in 14, and rework the JVMTI heap walk to stop messing around with
mark words in 15. Since this relates to concurrent root handling, 11-shenandoah is already safe.


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