ADDITIONAL SYSTEM INFORMATION :
openjdk 21 2023-09-19 LTS
OpenJDK Runtime Environment Corretto-21.0.0.35.1 (build 21+35-LTS)
OpenJDK 64-Bit Server VM Corretto-21.0.0.35.1 (build 21+35-LTS, mixed mode, sharing)


NAME="Ubuntu"
VERSION="20.04.5 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.5 LTS"
VERSION_ID="20.04"


A DESCRIPTION OF THE PROBLEM :
The changes introduced by JDK-8290025, https://bugs.openjdk.org/browse/JDK-8290025 , "Remove the Sweeper" have resulted in the code cache not being garbage collected when the code cache starts to get full. Resulting in "OpenJDK 64-Bit Server VM warning: CodeCache is full. Compiler has been disabled."

I expect the code cache to be garbage collected when it gets full, not only when other events invoke the GC.

I have tried to use various configurations for this. Combining the following without any luck. Some examples:

            - -XX:+UseCodeCacheFlushing
            - -XX:NmethodSweepActivity=10
            - -XX:SweeperThreshold=10

REGRESSION : Last worked in version 17

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Running an application with a heap with a lot of free space where the interval for garbage collection on the heap is low in combination with a code cache that is small, but not too small will reproduce this.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I would expect the code cache to be garbage-collected and not result in "OpenJDK 64-Bit Server VM warning: CodeCache is full. Compiler has been disabled."
ACTUAL -
The following is logged "OpenJDK 64-Bit Server VM warning: CodeCache is full. Compiler has been disabled." The code cache will be cleared on next GC, whenever that will be.

CUSTOMER SUBMITTED WORKAROUND :
Increasing the code cache

FREQUENCY : often