G1 crashes

[Doerr, Martin]

Hi,

we see a lot of G1 crashes when running JCK tests.
E.g.
api/java_util/TreeMap/EntrySetParallelStream.html

#  SIGSEGV (0xb) at pc=0x00007f5b557f2d15, pid=77863, tid=79363
#
# JRE version: OpenJDK Runtime Environment (16.0.0.1) (fastdebug build 16.0.0.1-internal+0-adhoc.openjdk.jdk)
# Java VM: OpenJDK 64-Bit Server VM (fastdebug 16.0.0.1-internal+0-adhoc.openjdk.jdk, mixed mode, sharing, tiered, compressed oops, g1 gc, linux-amd64)
# Problematic frame:
# V  [libjvm.so+0xae1d15]  G1ParScanThreadState::trim_queue_to_threshold(unsigned int)+0x4b5


Stack: [0x00007f5ae7afb000,0x00007f5ae7bfb000],  sp=0x00007f5ae7bf9930,  free space=1018k

Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)

V  [libjvm.so+0xae1d15]  G1ParScanThreadState::trim_queue_to_threshold(unsigned int)+0x4b5

V  [libjvm.so+0xb52f1a]  G1ParScanThreadState::trim_queue_partially()+0x3a

V  [libjvm.so+0xb5ad3f]  G1ScanHRForRegionClosure::scan_heap_roots(HeapRegion*)+0x8ef

V  [libjvm.so+0xb4f4dd]  G1RemSet::scan_heap_roots(G1ParScanThreadState*, unsigned int, G1GCPhaseTimes::GCParPhases, G1GCPhaseTimes::GCParPhases)+0x37d

V  [libjvm.so+0xa59d83]  G1EvacuateRegionsTask::scan_roots(G1ParScanThreadState*, unsigned int)+0x43

V  [libjvm.so+0xa5c187]  G1EvacuateRegionsBaseTask::work(unsigned int)+0x57

V  [libjvm.so+0x185782c]  GangWorker::loop()+0xac

V  [libjvm.so+0x17203f6]  Thread::call_run()+0xf6

V  [libjvm.so+0x133b706]  thread_native_entry(Thread*)+0x116



siginfo: si_signo: 11 (SIGSEGV), si_code: 1 (SEGV_MAPERR), si_addr: 0x0000000f7d7b844c

Seem like the thread has loaded garbage from the queue.
Is this a known problem?

Best regards,
Martin