The following test failed in the JDK16 CI:

vmTestbase/nsk/jvmti/scenarios/capability/CM01/cm01t016/TestDescription.java

Here's a snippet from the log file

#section:main
----------messages:(4/288)----------
command: main -agentlib:cm01t016=-waittime=5 nsk.jvmti.scenarios.capability.CM01.cm01t016
reason: User specified action: run main/othervm/native -agentlib:cm01t016=-waittime=5 nsk.jvmti.scenarios.capability.CM01.cm01t016
Mode: othervm [/othervm specified]
elapsed time (seconds): 11.689
----------configuration:(0/0)----------
----------System.out:(54/3226)----------
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x0000000108eefa41, pid=30820, tid=39939
#
# JRE version: Java(TM) SE Runtime Environment (16.0+9) (fastdebug build 16-ea+9-356)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 16-ea+9-356, compiled mode, sharing, tiered, compressed oops, g1 gc, bsd-amd64)
# Problematic frame:
# V [libjvm.dylib+0x4efa41] CodeStrings::free()+0x61
#
# Core dump will be written. Default location: core.30820
#
# An error report file with more information is saved as:
# /System/Volumes/Data/mesos/work_dir/slaves/1a7cca38-e299-473e-97af-f3151e5423d5-S6810/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/55ffb769-533c-427d-bcd6-d8a6df5ac6ae/runs/840ac9ca-ecba-4555-a61c-9ba9b9533af6/testoutput/test-support/jtreg_open_test_hotspot_jtreg_vmTestbase_nsk_jvmti_quick/scratch/1/hs_err_pid30820.log
Compiled method (c1) 7437 333 3 (method)
 total in heap [0x0000000118ac7810,0x0000000118acb460] = 15440
 relocation [0x0000000118ac7988,0x0000000118ac7e60] = 1240
 main code [0x0000000118ac7e60,0x0000000118ac9fa0] = 8512
 stub code [0x0000000118ac9fa0,0x0000000118aca148] = 424
 oops [0x0000000118aca148,0x0000000118aca150] = 8
 metadata [0x0000000118aca150,0x0000000118aca1d8] = 136
 scopes data [0x0000000118aca1d8,0x0000000118aca820] = 1608
 scopes pcs [0x0000000118aca820,0x0000000118acb390] = 2928
 dependencies [0x0000000118acb390,0x0000000118acb398] = 8
 handler table [0x0000000118acb398,0x0000000118acb3f8] = 96
 nul chk table [0x0000000118acb3f8,0x0000000118acb460] = 104
Compiled method (c1) 7437 333 3 (method)
 total in heap [0x0000000118ac7810,0x0000000118acb460] = 15440
 relocation [0x0000000118ac7988,0x0000000118ac7e60] = 1240
 main code [0x0000000118ac7e60,0x0000000118ac9fa0] = 8512
 stub code [0x0000000118ac9fa0,0x0000000118aca148] = 424
 oops [0x0000000118aca148,0x0000000118aca150] = 8
 metadata [0x0000000118aca150,0x0000000118aca1d8] = 136
 scopes data [0x0000000118aca1d8,0x0000000118aca820] = 1608
 scopes pcs [0x0000000118aca820,0x0000000118acb390] = 2928
 dependencies [0x0000000118acb390,0x0000000118acb398] = 8
 handler table [0x0000000118acb398,0x0000000118acb3f8] = 96
 nul chk table [0x0000000118acb3f8,0x0000000118acb460] = 104
Compiled method (c1) 7437 333 3 (method)
 total in heap [0x0000000118ac7810,0x0000000118acb460] = 15440
 relocation [0x0000000118ac7988,0x0000000118ac7e60] = 1240
 main code [0x0000000118ac7e60,0x0000000118ac9fa0] = 8512
 stub code [0x0000000118ac9fa0,0x0000000118aca148] = 424
 oops [0x0000000118aca148,0x0000000118aca150] = 8
 metadata [0x0000000118aca150,0x0000000118aca1d8] = 136
 scopes data [0x0000000118aca1d8,0x0000000118aca820] = 1608
 scopes pcs [0x0000000118aca820,0x0000000118acb390] = 2928
 dependencies [0x0000000118acb390,0x0000000118acb398] = 8
 handler table [0x0000000118acb398,0x0000000118acb3f8] = 96
 nul chk table [0x0000000118acb3f8,0x0000000118acb460] = 104
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
----------System.err:(0/0)----------
----------rerun:(46/8775)*----------


Here's the crashing thread's stack:

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

Current thread (0x00007f8ac7811a20): JavaThread "Sweeper thread" daemon [_thread_in_vm, id=39939, stack(0x0000700009c49000,0x0000700009d49000)]

Stack: [0x0000700009c49000,0x0000700009d49000], sp=0x0000700009d48bf0, free space=1022k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0x4efa41] CodeStrings::free()+0x61
V [libjvm.dylib+0xd7035a] nmethod::flush()+0x25a
V [libjvm.dylib+0xf8be2b] NMethodSweeper::process_compiled_method(CompiledMethod*)+0x10b
V [libjvm.dylib+0xf8b6db] NMethodSweeper::sweep_code_cache()+0x29b
V [libjvm.dylib+0xf8af9e] NMethodSweeper::sweep()+0x1be
V [libjvm.dylib+0xf8ac75] NMethodSweeper::sweeper_loop()+0x25
V [libjvm.dylib+0x10029b0] JavaThread::thread_main_inner()+0x2a0
V [libjvm.dylib+0xffdd07] Thread::call_run()+0x1b7
V [libjvm.dylib+0xdc35ff] thread_native_entry(Thread*)+0x15f
C [libsystem_pthread.dylib+0x6109] _pthread_start+0x94
C [libsystem_pthread.dylib+0x1b8b] thread_start+0xf


siginfo: si_signo: 11 (SIGSEGV), si_code: 1 (SEGV_MAPERR), si_addr: 0x00006f8ac4c7c078