RFA: 8166197: assert(RelaxAssert || w != Thread::current()->_MutexEvent) failed: invariant

[Hohensee, Paul]

Lgtm.

Thanks,
Paul

-----Original Message-----
From: jdk8u-dev <jdk8u-dev-retn at openjdk.java.net> on behalf of "Yangfei (Felix)" <felix.yang at huawei.com>
Date: Monday, August 9, 2021 at 12:33 AM
To: jdk8u-dev <jdk8u-dev at openjdk.java.net>
Subject: RFA: 8166197: assert(RelaxAssert || w != Thread::current()->_MutexEvent) failed: invariant

Hi,

Please review this 8u backport fixing a memory-ordering issue.

Original bug: https://bugs.openjdk.java.net/browse/JDK-8166197
Original patch: https://github.com/openjdk/jdk11u-dev/commit/7e084fd81fc5ef3e8245dc2381d4f13c016746c5
Original RFR thread: https://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2016-October/021565.html

Note that original bug is closed for review so I cannot add labels.
This issue can be reproduced stably on my 128-core aarch64 server with 8u fastdebug build by running this jtreg test:
$ jtreg -othervm hotspot/test/stress/gc/TestStressRSetCoarsening.java
Crash log looks like [1].

Original 11u patch cannot be applied cleanly due to changes in surrounding context.
8u webrev: http://cr.openjdk.java.net/~fyang/8166197-8u/webrev.00

Tested with jtreg using 8u aarch64 fastdebug build. The above mentioned jtreg test failed quickly before fix and pass after.

Thanks,
Felix

[1]
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc:  SuppressErrorAt=/mutex.cpp:589
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/home/yangfei/openjdk8u-dev/hotspot/src/share/vm/runtime/mutex.cpp:589), pid=27757, tid=0x0000fffed1fe61e0
#  assert(RelaxAssert || w != Thread::current()->_MutexEvent) failed: invariant
#
# JRE version: OpenJDK Runtime Environment (8.0) (build 1.8.0-internal-fastdebug-yangfei_2021_08_09_10_45-b00)
# Java VM: OpenJDK 64-Bit Server VM (25.71-b00-fastdebug mixed mode linux-aarch64 compressed oops)
# Core dump written. Default location: /home/yangfei/openjdk8u-dev/JTwork/scratch/4/core or core.27757
#
# An error report file with more information is saved as:
# /home/yangfei/openjdk8u-dev/JTwork/scratch/4/hs_err_pid27757.log
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
#
Current thread is 281469909885408
Dumping core ...