Possibly after the fix for 8155943, during the jdk9/hs build there are messages coming out like:

AllocatedObj(0x00007ffff0032d80)

This is coming from g1DefaultPolicy.cpp:593

  NOT_PRODUCT(_short_lived_surv_rate_group->print());


(gdb) bt
#0 AllocatedObj::print (this=0x7ffff0032d80) at /home/eric/views/hs/hotspot/src/share/vm/memory/allocation.cpp:725
#1 0x00007ffff5f13712 in G1DefaultPolicy::record_collection_pause_end (this=0x7ffff002bf80, pause_time_ms=29.250542999996298, cards_scanned=0, heap_used_bytes_before_gc=25165824) at /home/eric/views/hs/hotspot/src/share/vm/gc/g1/g1DefaultPolicy.cpp:593
#2 0x00007ffff5eeb5e7 in G1CollectedHeap::do_collection_pause_at_safepoint (this=0x7ffff002cc50, target_pause_time_ms=200) at /home/eric/views/hs/hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp:3364
#3 0x00007ffff66dae95 in VM_G1IncCollectionPause::doit (this=0x7ffff7fd0610) at /home/eric/views/hs/hotspot/src/share/vm/gc/g1/vm_operations_g1.cpp:148
#4 0x00007ffff66d8650 in VM_Operation::evaluate (this=0x7ffff7fd0610) at /home/eric/views/hs/hotspot/src/share/vm/runtime/vm_operations.cpp:67
#5 0x00007ffff66d581b in VMThread::evaluate_operation (this=0x7ffff0348800, op=0x7ffff7fd0610) at /home/eric/views/hs/hotspot/src/share/vm/runtime/vmThread.cpp:353
#6 0x00007ffff66d5e85 in VMThread::loop (this=0x7ffff0348800) at /home/eric/views/hs/hotspot/src/share/vm/runtime/vmThread.cpp:475
#7 0x00007ffff66d5591 in VMThread::run (this=0x7ffff0348800) at /home/eric/views/hs/hotspot/src/share/vm/runtime/vmThread.cpp:266
#8 0x00007ffff644926a in java_start (thread=0x7ffff0348800) at /home/eric/views/hs/hotspot/src/os/linux/vm/os_linux.cpp:688
#9 0x00007ffff79ab182 in start_thread (arg=0x7fff1d3fb700) at pthread_create.c:312
#10 0x00007ffff72c047d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

If you do a slowdebug build you should see these msgs or when done do -version like this:

./build/linux-x64/jdk/bin/java -version
AllocatedObj(0x00007f2e4c032d80)
java version "9-internal"
Java(TM) SE Runtime Environment (slowdebug build 9-internal+0-2016-05-04-164211.eric.hs)
Java HotSpot(TM) 64-Bit Server VM (slowdebug build 9-internal+0-2016-05-04-164211.eric.hs, mixed mode)