JDK-8256385 : C2: fatal error: modified node is not on IGVN._worklist
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 16
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2020-11-16
  • Updated: 2020-11-26
  • Resolved: 2020-11-18
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
JDK 16
16 b26Fixed
Related Reports
Relates :  
JDK-8255665 - C2 should aggressively remove temporary hook nodes
Description
The attached fuzzer test fails with the following fatal error.

To reproduce:
$ java -XX:CompileOnly=Test
or 
$ java -Xmx1G -Xcomp -Xbatch -XX:-TieredCompilation -XX:CompileOnly=Test

 934  MergeMem  === _  1  407  1  1  1  1  1  1  1  1  683  [[]]  { - - - - - - - - N683:java/lang/Class:exact+156 * }  Memory: @BotPTR *+bot, idx=Bot; !orig=688 !jvms: Test::iMeth @ bci:169
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/opt/mach5/mesos/work_dir/slaves/47535081-0322-4d83-bb78-f7e11abb86d0-S45878/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/c909db09-6c9b-402f-b3f3-aca8c6860a96/runs/991019b7-aa93-4076-a8df-1733e5f45dc3/workspace/open/src/hotspot/share/opto/phaseX.cpp:1074), pid=27513, tid=27526
#  fatal error: modified node is not on IGVN._worklist
#
# JRE version: Java(TM) SE Runtime Environment (16.0+24) (fastdebug build 16-ea+24-1553)
...........
Command Line: -Xmx1G -Xcomp -Xbatch -XX:CompileOnly=Test Test
...........
Current thread (0x00007f27c04842d0):  JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=27526, stack(0x00007f27986fb000,0x00007f27987fc000)]


Current CompileTask:
C2:    216   12    b  4       Test::iMeth (312 bytes)

Stack: [0x00007f27986fb000,0x00007f27987fc000],  sp=0x00007f27987f6aa0,  free space=1006k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x15ecde0]  PhaseIterGVN::init_verifyPhaseIterGVN()+0x140
V  [libjvm.so+0x15ee0a9]  PhaseIterGVN::optimize()+0x19
V  [libjvm.so+0x9fb76a]  PhaseIdealLoop::optimize(PhaseIterGVN&, LoopOptsMode)+0x6ca
V  [libjvm.so+0x9f68a6]  Compile::Optimize()+0x6b6
V  [libjvm.so+0x9f9470]  Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x1820
V  [libjvm.so+0x82c6ee]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x1ce
V  [libjvm.so+0xa095f8]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0xe08
V  [libjvm.so+0xa0a148]  CompileBroker::compiler_thread_loop()+0x5a8
V  [libjvm.so+0x1886f56]  JavaThread::thread_main_inner()+0x256
V  [libjvm.so+0x188dc10]  Thread::call_run()+0x100
V  [libjvm.so+0x1570066]  thread_native_entry(Thread*)+0x116
Comments
Changeset: f504f419 Author: Tobias Hartmann <thartmann@openjdk.org> Date: 2020-11-18 11:53:25 +0000 URL: https://github.com/openjdk/jdk/commit/f504f419
18-11-2020
Right, it's a dead node that has not been added to the IGVN worklist for removal. ILW = Assert due to dead node not being reclaimed (does not affect product), reproducible with fuzzer generated test, no workaround but disable compilation = MMH = P3
16-11-2020
Starts to fail after JDK-8255665 but that might just revealed an existing problem.
16-11-2020