> [JDK-8374045](https://bugs.openjdk.org/browse/JDK-8374045) > > This PR adds a new utility tool CodeCacheFragmenter to help with testing > HotSpot code cache fragmentation scenarios. The tool is a Java agent that > uses the WhiteBox API to create and randomly free dummy code blobs in the > NonProfiled code heap to achieve a specified fill percentage. It includes > configurable parameters for blob sizes, target fill percentage (0-100%), and > random seeding to enable reproducible fragmentation patterns. The utility is > built via a standard Makefile and produces `codecachefragmenter.jar` which > can be used as a Java agent with `-javaagent` flag. This tool is intended for > performance testing and experimentation with code cache behavior under > various fragmentation conditions. > > This is useful to show the performance benefits of > [JDK-8326205](https://bugs.openjdk.org/browse/JDK-8326205) > > With the same amount of free code cache memory, adding fragmentation > increases execution time of Renaissance Dotty by ~5x. See > https://github.com/openjdk/jdk/pull/28934#issuecomment-3820151693 for more > details.
Chad Rakoczy has updated the pull request incrementally with one additional commit since the last revision: Update rng ------------- Changes: - all: https://git.openjdk.org/jdk/pull/28934/files - new: https://git.openjdk.org/jdk/pull/28934/files/c2108d55..f40ad8c1 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=28934&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28934&range=00-01 Stats: 18 lines in 2 files changed: 2 ins; 5 del; 11 mod Patch: https://git.openjdk.org/jdk/pull/28934.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/28934/head:pull/28934 PR: https://git.openjdk.org/jdk/pull/28934
