In order to ease the next upstream merge, and because the patch does not even conflict, I'd like to cherry-pick: 8214055: GC/C2 abstraction for phaseX and move/add the corresponding Shenandoah parts. http://cr.openjdk.java.net/~rkennke/JDK-8214055-shenandoah/webrev.01/ Testing: tier3_gc_shenandoah Ok? Roman