Shenandoah Crash in Minecraft

[Aleksey Shipilev]

On 8/8/19 9:32 AM, Aleksey Shipilev wrote:
> On 8/7/19 11:19 PM, Robin Kuiper wrote:
>> Crash log: 
>> https://bugs.mojang.com/browse/MC-158532
>> https://bugs.mojang.com/secure/attachment/230803/hs_err_pid1036.log
> 
> Are you sure this is Shenandoah-specific? Can you try without Shenandoah, and hopefully with
> fastdebug builds? You can pick some at https://builds.shipilev.net/.
Reproduced this with jdk12 release bits like below. This is C2 compiler crash when expanding the
barriers, so it is Shenandoah specific. This does not reproduce on latest jdk13u or bleeding edge
jdk release bits. It also works fine with fastdebug versions of them, after I hack out the
assert_field_offset_sane.

That said, 12.0.2 is the last release in that short-term support train, soon (in September) to be
superseded by 13. So, even if we were able to fix it in 12, we would not be able to ship the updated
binary. I suggest either running with stable 11 and/or early access 13.

---- 8< -----------------------------------------------------------------------------------------

# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007f5119511951, pid=13539, tid=13550
#
# JRE version: OpenJDK Runtime Environment (12.0.2) (build
12.0.2-testing+0-builds.shipilev.net-openjdk-jdk12-b202-20190806-jdk-12.0.210jdk-12.0.2-ga)
# Java VM: OpenJDK 64-Bit Server VM
(12.0.2-testing+0-builds.shipilev.net-openjdk-jdk12-b202-20190806-jdk-12.0.210jdk-12.0.2-ga, mixed
mode, sharing, tiered, compressed oops, shenandoah gc, linux-amd64)
# Problematic frame:
# V  [libjvm.so+0xaa1951]  PhaseIdealLoop::build_loop_late_post_work(Node*, bool)+0x151

...

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

Current thread (0x00007f51141b5000):  JavaThread "C2 CompilerThread0" daemon [_thread_in_native,
id=13550, stack(0x00007f50f9299000,0x00007f50f939a000)]


Current CompileTask:
C2:   8880 8438       4       dyq::a (62 bytes)

Stack: [0x00007f50f9299000,0x00007f50f939a000],  sp=0x00007f50f9394c90,  free space=1007k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native
code)
V  [libjvm.so+0xaa1951]  PhaseIdealLoop::build_loop_late_post_work(Node*, bool)+0x151
V  [libjvm.so+0xd82d0d]  ShenandoahBarrierNode::build_loop_late_post(PhaseIdealLoop*, Node*)+0x5d
V  [libjvm.so+0xaa1ed8]  PhaseIdealLoop::build_loop_late(VectorSet&, Node_List&, Node_Stack&)+0x2a8
V  [libjvm.so+0xaa4888]  PhaseIdealLoop::build_and_optimize(LoopOptsMode)+0x6d8
V  [libjvm.so+0xd80dc4]  ShenandoahWriteBarrierNode::expand(Compile*, PhaseIterGVN&)+0x104
V  [libjvm.so+0xd04f1f]  ShenandoahBarrierSetC2::expand_barriers(Compile*, PhaseIterGVN&) const+0xf

siginfo: si_signo: 11 (SIGSEGV), si_code: 1 (SEGV_MAPERR), si_addr: 0x0000000000000008

---- 8< -----------------------------------------------------------------------------------------


-- 
Thanks,
-Aleksey