[jdk11u-dev] RFR: JDK-8306768: CodeCache Analytics reports wrong threshold

[Anton Kozlov]

Jcmd CodeCache_Analytics uses own implementation of threshold calculation, allowing an error to creep in, making report invalid. The suggestion is to use the existing method for free ratio calculation. After the fix, the reported values become sane.


java -XX:InitialCodeCacheSize=1G -XX:ReservedCodeCacheSize=1G ...

cmd jdk.compiler/com.sun.tools.javac.launcher.Main  Compiler.CodeHeap_Analytics | grep -A 2 "Threshold for method to be considered 'cold'"
Threshold for method to be considered 'cold':    -2037.994
min. hotness =   1016
avg. hotness =   2048
--
Threshold for method to be considered 'cold':    -2037.961
min. hotness =   1016
avg. hotness =   2048
--
Threshold for method to be considered 'cold':    -2031.906
No hotness data available

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Commit messages:
 - JDK-8306768: CodeCache Analytics reports wrong threshold

Changes: https://git.openjdk.org/jdk11u-dev/pull/1849/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1849&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306768
  Stats: 3 lines in 1 file changed: 1 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1849.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/1849/head:pull/1849

PR: https://git.openjdk.org/jdk11u-dev/pull/1849