SIGSEGV crash in ObjectMonitor::enter with latest Shenandoah JDK8

[Aleksey Shipilev]

On 11/4/19 4:44 PM, Alexander Yakushev wrote:
> Hello again! After some time, I finally managed to reproduce the crash in a non-production
> environment with +ShenandoahVerify. I attach the hs_err file.

Thanks. I notice that you are running in the unusual configuration:
  -Xmx12g -Xms12g -XX:ObjectAlignmentInBytes=16

Alignment to 16 bytes is not needed for the heap this small, and it just wastes memory.

We are trying to see if that could be the source of bugs too...

> This was reproduced with a regular shenandoah-jdk8 build. Meanwhile, I've built the application with
> fastdebug build and will try with that too if necessary.

Yes, that would be handy. The current hs_err does not yield interesting failure, it seems to be NULL
dereference somewhere ObjectMonitor code -- which may or may not be the GC fault. Need to meditate
on this a little bit...

-- 
Thanks,
-Aleksey