RFR: 8343789: Move mutable nmethod data out of CodeCache [v6]

[Boris Ulasevich]

On Thu, 9 Jan 2025 01:23:18 GMT, Dean Long <dlong at openjdk.org> wrote:

> I just noticed the old code would have replaced the oop_Relocation with a internal_word_Relocation for the NearCpool==false case. How did that ever work correctly?

Thanks for review!

NearCpool==false was not functioning correctly. I had considered a separate [fix](https://github.com/openjdk/jdk/pull/22448/files) for it, but with the current change, the incorrect code is eliminated.


$ ~/jdk-23/bin/java -XX:-NearCpool -XX:+UseShenandoahGC -version
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x0000ffff6f94c190, pid=95263, tid=95264
#
# JRE version: OpenJDK Runtime Environment (23.0+38) (build 23+38)
# Java VM: OpenJDK 64-Bit Server VM (23+38, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, shenandoah gc, linux-aarch64)
# Problematic frame:
# j  java.lang.module.ModuleDescriptor.<init>(Ljava/lang/String;Ljava/lang/module/ModuleDescriptor$Version;Ljava/util/Set;Ljava/util/Set;Ljava/util/Set;Ljava/util/Set;Ljava/util/Set;Ljava/util/Set;Ljava/util/Set;Ljava/lang/String;IZ)V+29 java.base
#
# Core dump will be written.

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PR Comment: https://git.openjdk.org/jdk/pull/21276#issuecomment-2582462847