Stress test fails with 

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (open/src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp:1171), pid=21157, tid=21182
#  assert(dominators_of_region <= 1) failed: More than one region can't require extra phi
#
# JRE version: Java(TM) SE Runtime Environment (14.0+11) (fastdebug build 14-ea+11-348)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 14-ea+11-348, mixed mode, tiered, z gc, linux-amd64)
# Problematic frame:
# V  [libjvm.so+0x1811b4a]  call_catch_cleanup_one(PhaseIdealLoop*, LoadNode*, Node*)+0xd8a
#
# Core dump will be written. Default location: /scratch/opt/mach5/mesos/work_dir/slaves/00f4d7f9-7805-4b6a-aef8-9bb130db2435-S1269/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/86acc7f9-543d-41a7-8b4b-a9af42f55147/runs/a1c43464-5e7d-4a7a-94bb-db909380a358/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo24H_java/scratch/0/core.21157
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
#

---------------  S U M M A R Y ------------

Command Line: -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:MaxRAMPercentage=8 -XX:+UnlockExperimentalVMOptions -XX:+UseZGC -XX:MaxRAMPercentage=50 -XX:+HeapDumpOnOutOfMemoryError -XX:+CrashOnOutOfMemoryError -XX:+DisplayVMOutputToStderr -Xlog:gc*,gc+heap=debug:gc.log:uptime,timemillis,level,tags -XX:+DisableExplicitGC -XX:+StartAttachListener -Djava.io.tmpdir=/scratch/opt/mach5/mesos/work_dir/slaves/00f4d7f9-7805-4b6a-aef8-9bb130db2435-S1269/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/86acc7f9-543d-41a7-8b4b-a9af42f55147/runs/a1c43464-5e7d-4a7a-94bb-db909380a358/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo24H_java/scratch/0/java.io.tmpdir -Duser.home=/scratch/opt/mach5/mesos/work_dir/slaves/00f4d7f9-7805-4b6a-aef8-9bb130db2435-S1269/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/86acc7f9-543d-41a7-8b4b-a9af42f55147/runs/a1c43464-5e7d-4a7a-94bb-db909380a358/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo24H_java/scratch/0/user.home applications.kitchensink.process.stress.Main /scratch/opt/mach5/mesos/work_dir/slaves/00f4d7f9-7805-4b6a-aef8-9bb130db2435-S1269/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/86acc7f9-543d-41a7-8b4b-a9af42f55147/runs/a1c43464-5e7d-4a7a-94bb-db909380a358/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo24H_java/scratch/0/kitchensink.final.properties

Host: Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz, 6 cores, 28G, Oracle Linux Server release 7.6
Time: Wed Aug 21 05:25:33 2019 UTC elapsed time: 1355 seconds (0d 0h 22m 35s)

---------------  T H R E A D  ---------------

Current thread (0x00007f55dc2a5cc0):  JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=21182, stack(0x00007f55b490d000,0x00007f55b4a0e000)]


Current CompileTask:
C2:1355988 82016       4       org.eclipse.jdt.internal.compiler.parser.AbstractCommentParser::parseQualifiedName (814 bytes)

Stack: [0x00007f55b490d000,0x00007f55b4a0e000],  sp=0x00007f55b4a08250,  free space=1004k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x1811b4a]  call_catch_cleanup_one(PhaseIdealLoop*, LoadNode*, Node*)+0xd8a
V  [libjvm.so+0x1814aea]  ZBarrierSetC2::optimize_loops(PhaseIdealLoop*, LoopOptsMode, VectorSet&, Node_Stack&, Node_List&) const+0x41a
V  [libjvm.so+0x11dcb5e]  PhaseIdealLoop::build_and_optimize(LoopOptsMode)+0xfbe
V  [libjvm.so+0x9c5afa]  PhaseIdealLoop::optimize(PhaseIterGVN&, LoopOptsMode)+0x2ea
V  [libjvm.so+0x9c2f91]  Compile::Optimize()+0xf21
V  [libjvm.so+0x9c424f]  Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool, DirectiveSet*)+0x109f
V  [libjvm.so+0x806c3d]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, DirectiveSet*)+0x10d
V  [libjvm.so+0x9d0b50]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0x3e0
V  [libjvm.so+0x9d1b48]  CompileBroker::compiler_thread_loop()+0x3b8
V  [libjvm.so+0x16c41c2]  JavaThread::thread_main_inner()+0x312
V  [libjvm.so+0x16cc37f]  JavaThread::run()+0x29f
V  [libjvm.so+0x16c9276]  Thread::call_run()+0xf6
V  [libjvm.so+0x13e95ee]  thread_native_entry(Thread*)+0x10e

Register to memory mapping:

RAX=0x00007f55e35e6000 points into unknown readable memory: 58 00 00 00 00 00 00 00
RBX=0x00007f532c6e3200 points into unknown readable memory: e0 b9 8b e2 55 7f 00 00
RCX=0x00007f55e251f128: <offset 0x00000000019d8128> in /scratch/opt/mach5/mesos/work_dir/jib-master/install/jdk-14+11-348/linux-x64-debug.jdk/jdk-14/fastdebug/lib/server/libjvm.so at 0x00007f55e0b47000
RDX=0x00007f55e251f158: <offset 0x00000000019d8158> in /scratch/opt/mach5/mesos/work_dir/jib-master/install/jdk-14+11-348/linux-x64-debug.jdk/jdk-14/fastdebug/lib/server/libjvm.so at 0x00007f55e0b47000
RSP=0x00007f55b4a08250 is pointing into the stack for thread: 0x00007f55dc2a5cc0
RBP=0x00007f55b4a08320 is pointing into the stack for thread: 0x00007f55dc2a5cc0
RSI=0x0000000000000493 is an unknown value
RDI=0x00007f55e251e478: <offset 0x00000000019d7478> in /scratch/opt/mach5/mesos/work_dir/jib-master/install/jdk-14+11-348/linux-x64-debug.jdk/jdk-14/fastdebug/lib/server/libjvm.so at 0x00007f55e0b47000
R8 =0x00007f55dc2a7690 points into unknown readable memory: 04 00 00 00 00 00 00 00
R9 =0x0000000000000016 is an unknown value
R10=0x00007f52f0e27348 points into unknown readable memory: d8 b8 8b e2 55 7f 00 00
R11=0x00007f55e2b8b700: <offset 0x000000000018d700> in /lib64/libc.so.6 at 0x00007f55e29fe000
R12=0x0000000000000008 is an unknown value
R13=0x00007f52dc200f80 points into unknown readable memory: 70 54 8b e2 55 7f 00 00
R14=0x00007f55b4a08a20 is pointing into the stack for thread: 0x00007f55dc2a5cc0
R15=0x0000000000000001 is an unknown value


Registers:
RAX=0x00007f55e35e6000, RBX=0x00007f532c6e3200, RCX=0x00007f55e251f128, RDX=0x00007f55e251f158
RSP=0x00007f55b4a08250, RBP=0x00007f55b4a08320, RSI=0x0000000000000493, RDI=0x00007f55e251e478
R8 =0x00007f55dc2a7690, R9 =0x0000000000000016, R10=0x00007f52f0e27348, R11=0x00007f55e2b8b700
R12=0x0000000000000008, R13=0x00007f52dc200f80, R14=0x00007f55b4a08a20, R15=0x0000000000000001
RIP=0x00007f55e2358b4a, EFLAGS=0x0000000000010202, CSGSFS=0x0000000000000033, ERR=0x0000000000000006
  TRAPNO=0x000000000000000e

Top of Stack: (sp=0x00007f55b4a08250)
0x00007f55b4a08250:   00007f55b4a00000 00000001dcfb6af8
0x00007f55b4a08260:   00007f532c9ad798 00007f52dc200f80
0x00007f55b4a08270:   00007f532cd08050 00007f52dc200c20
0x00007f55b4a08280:   00007f5375c5dcc0 00000000000c0c20 

Instructions: (pc=0x00007f55e2358b4a)
0x00007f55e2358a4a:   49 89 c5 4d 89 fe 4c 8b 7d c8 e9 b8 fa ff ff 4c
0x00007f55e2358a5a:   8d 05 80 a9 59 00 48 8d 0d 32 23 23 00 48 8d 15
0x00007f55e2358a6a:   52 65 1c 00 be 54 04 00 00 48 8d 3d fe 59 1c 00
0x00007f55e2358a7a:   49 8b 00 c6 00 58 31 c0 e8 59 fb 26 ff e8 04 f5
0x00007f55e2358a8a:   bc ff e9 b3 fb ff ff c7 45 90 00 00 00 00 e9 b1
0x00007f55e2358a9a:   f5 ff ff 31 d2 be 78 00 00 00 48 89 cf e8 04 d8
0x00007f55e2358aaa:   dc fe 48 89 85 50 ff ff ff e9 bd fc ff ff 48 8d
0x00007f55e2358aba:   05 21 a9 59 00 48 8d 0d 24 23 23 00 48 8d 15 7b
0x00007f55e2358aca:   67 1c 00 be b3 04 00 00 48 8d 3d 9f 59 1c 00 48
0x00007f55e2358ada:   8b 00 c6 00 58 31 c0 e8 fa fa 26 ff e8 a5 f4 bc
0x00007f55e2358aea:   ff e9 bb f7 ff ff 48 8d 72 1c 48 8d 7a 08 31 d2
0x00007f55e2358afa:   e8 91 7a ff ff 0f b7 50 30 83 e2 07 66 83 fa 07
0x00007f55e2358b0a:   0f 85 0c f3 ff ff 48 85 c0 0f 85 36 f3 ff ff e9
0x00007f55e2358b1a:   fe f2 ff ff 66 90 83 7d a8 01 7e 33 48 8d 05 b3
0x00007f55e2358b2a:   a8 59 00 48 8d 0d f4 65 1c 00 48 8d 15 1d 66 1c
0x00007f55e2358b3a:   00 be 93 04 00 00 48 8d 3d 31 59 1c 00 48 8b 00
0x00007f55e2358b4a:   c6 00 58 31 c0 e8 8c fa 26 ff e8 37 f4 bc ff 80
0x00007f55e2358b5a:   7d a7 00 0f 85 ed 01 00 00 48 8b 95 58 ff ff ff
0x00007f55e2358b6a:   48 89 de 4c 89 f7 e8 2b 90 ff ff 48 8b 9d 60 ff
0x00007f55e2358b7a:   ff ff 48 89 45 90 8b 40 28 48 89 c1 48 8b 04 c3
0x00007f55e2358b8a:   48 89 45 b8 48 85 c0 74 18 0f b7 40 30 66 89 85
0x00007f55e2358b9a:   6a ff ff ff 83 e0 0f 66 83 f8 0c 0f 84 05 02 00
0x00007f55e2358baa:   00 48 8b 45 80 48 8b 58 70 48 85 db 0f 84 26 02
0x00007f55e2358bba:   00 00 e8 df eb c4 fe 31 d2 be 78 00 00 00 48 8b
0x00007f55e2358bca:   80 08 05 00 00 48 8b b8 90 00 00 00 48 81 c7 18
0x00007f55e2358bda:   02 00 00 e8 9e e8 c2 ff 48 89 45 b8 48 85 c0 74
0x00007f55e2358bea:   5c 4c 8b 65 90 48 89 c7 49 89 c7 41 8b 74 24 18
0x00007f55e2358bfa:   e8 31 6f b6 ff ba 0c 00 00 00 49 89 5f 58 31 f6
0x00007f55e2358c0a:   48 8d 05 37 7d 55 00 66 41 89 57 30 4c 89 ff 4c
0x00007f55e2358c1a:   89 e2 66 0f 6f 0d 5c 3b 23 00 49 c7 47 60 00 00
0x00007f55e2358c2a:   00 00 48 83 c0 10 49 89 07 41 0f 11 4f 68 e8 23
0x00007f55e2358c3a:   d1 da fe 31 f6 4c 89 ff e8 89 91 03 ff 48 8b 45 


Stack slot to memory mapping:
stack at sp + 0 slots: 0x00007f55b4a00000 is pointing into the stack for thread: 0x00007f55dc2a5cc0
stack at sp + 1 slots: 0x00000001dcfb6af8 is an unknown value
stack at sp + 2 slots: 0x00007f532c9ad798 points into unknown readable memory: 18 d8 9a 2c 53 7f 00 00
stack at sp + 3 slots: 0x00007f52dc200f80 points into unknown readable memory: 70 54 8b e2 55 7f 00 00
stack at sp + 4 slots: 0x00007f532cd08050 points into unknown readable memory: 58 09 8b e2 55 7f 00 00
stack at sp + 5 slots: 0x00007f52dc200c20 points into unknown readable memory: 28 25 8e e2 55 7f 00 00
stack at sp + 6 slots: 0x00007f5375c5dcc0 points into unknown readable memory: 00 00 00 00 00 00 00 00
stack at sp + 7 slots: 0x00000000000c0c20 is an unknown value