Application failure with traversal

[Lennart Börjeson]

> 9 feb. 2018 kl. 19:18 skrev Lennart Börjeson <lennart.borjeson at cinnober.com>:
> 
> 
> 
>> 9 feb. 2018 kl. 18:36 skrev Aleksey Shipilev <shade at redhat.com>:
>> 
>> On 02/09/2018 06:27 PM, Lennart Börjeson wrote:
>>>> c) C2: -XX:-TieredCompilation
>>> 
>>> Fails.
>> 
>> OK, both good and bad! And that is without any GC cycle happening, right? If so, that must
>> definitely point at something gone wrong in C2, which means we can use passive mode, and gradually
>> narrow down which part had failed (in order of most probability):
>> 
>> 0) Run with -XX:-TieredCompilation -XX:ShenandoahGCHeuristics=passive
> Runs OK.
>> 1) Add -XX:+ShenandoahBarriersForConst
> Runs OK.
>> 2) Add -XX:+ShenandoahAsmWB
> Runs OK.
>> 3) Add -XX:+ShenandoahReadBarrier
> Fails.
>> 4) Add -XX:+ShenandoahWriteBarrier
> Fails.
>> 5) Add -XX:-ShenandoahWriteBarrierRB
> Fails.
>> 6) Add -XX:+ShenandoahStoreValEnqueueBarrier
> Fails.
>> 7) Add -XX:+ShenandoahCASBarrier
> Fails.
>> 8) Add -XX:+ShenandoahAcmpBarrier
> Fails.
>> 9) Add -XX:+ShenandoahCloneBarrier
> Fails.
>> 
>> -Aleksey
>> 
> 
> I also ran with all barriers except ReadBarrier enabled, i.e. with -XX:-TieredCompilation -XX:ShenandoahGCHeuristics=passive -XX:+ShenandoahBarriersForConst -XX:+ShenandoahAsmWB -XX:-ShenandoahReadBarrier -XX:+ShenandoahWriteBarrier -XX:-ShenandoahWriteBarrierRB -XX:+ShenandoahStoreValEnqueueBarrier  -XX:+ShenandoahCASBarrier -XX:+ShenandoahAcmpBarrier -XX:+ShenandoahCloneBarrier
> 
> Run OK.

Sorry, missed a barrier in that test, but enabling ShenandoahWriteBarrierRB didn't cause any failure, i.e. 
-XX:-TieredCompilation 
-XX:ShenandoahGCHeuristics=passive 
-XX:+ShenandoahBarriersForConst 
-XX:+ShenandoahAsmWB 
-XX:-ShenandoahReadBarrier 
-XX:+ShenandoahWriteBarrier 
-XX:+ShenandoahWriteBarrierRB 
-XX:+ShenandoahStoreValEnqueueBarrier  
-XX:+ShenandoahCASBarrier 
-XX:+ShenandoahAcmpBarrier 
-XX:+ShenandoahCloneBarrier

This test ran OK.

/Lennart