Expected behavior

Same performance as previous patch version 4.1.51 which on my machine was:
11,778 ± 1,185 ops/us

Actual behavior

4,946 ± 0,143 ops/us

Steps to reproduce

Run with JMH something like:

ByteBuf buf = PooledByteBufAllocator.DEFAULT.directBuffer( 32768 );
buf.release();

Minimal yet complete reproducer code (or URL to code)

see above

Netty version

4.1.52

JVM version (e.g. java -version)

openjdk version "11.0.7" 2020-04-14
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.7+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.7+10, mixed mode)

OS version (e.g. uname -a)

Darwin E87 18.7.0 Darwin Kernel Version 18.7.0: Mon Apr 27 20:09:39 PDT 2020; root:xnu-4903.278.35~1/RELEASE_X86_64 x86_64
(macOS Mojave)