RFR: 8282153 JFR: Check for recording waste

Fri Feb 25 11:44:58 UTC 2022

On Wed, 23 Feb 2022 09:47:33 GMT, Erik Gahlin <egahlin at openjdk.org> wrote:

> Hi,
> 
> Could I have a review of test that looks for wasted space in recording files. Waste is typically constant pool data that is not referenced by an event. There have been issues with this in the past. 
> 
> I set an upper limit of 2% waste. It's typically around 0,7% in the test. Unused threads create waste and something we may want to prevent in the future. The fix relies on the method RecordingFile::write(Path, Predicate) being added. See "JDK-8271232: JFR: Scrub recording data"
> 
> The test prints a histogram of the event types to make sure expected events are emitted.
> 
> Testing: jdk/jdk/jfr/jvm/TestWaste.java 100 times
> 
> Thanks
> Erik

Marked as reviewed by mgronlun (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/7586