RFR: 8335397: Improve reliability of TestRecursiveMonitorChurn.java

[Coleen Phillimore]

On Mon, 1 Jul 2024 09:21:13 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

> TestRecursiveMonitorChurn.java currently uses NMT to try and correlate the native memory increase with unwanted inflation.
> 
> Change to instead query the JVM for exact number of inflations via the Whitebox API. This allow us to both be more exact and less dependent on interactions with NMT.

This is an improvement.

test/hotspot/jtreg/runtime/locking/TestRecursiveMonitorChurn.java line 58:

> 56:     public static void main(String[] args) {
> 57:         if (WB.getIntVMFlag("LockingMode") == LM_MONITOR) {
> 58:             throw new SkippedException("LM_MONITOR always infaltes. Invalid test.");

typo: inflates

test/hotspot/jtreg/runtime/locking/TestRecursiveMonitorChurn.java line 85:

> 83:                     long reserved = Long.parseLong(m.group(1));
> 84:                     long committed = Long.parseLong(m.group(2));
> 85:                     System.out.println(">>>>> " + line + ": " + reserved + " - " + committed);

Oh so it just measures how much memory we use for ObjectMonitors?  yes, this doesn't seem very reliable.

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Marked as reviewed by coleenp (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/19965#pullrequestreview-2154070059
PR Review Comment: https://git.openjdk.org/jdk/pull/19965#discussion_r1662670355
PR Review Comment: https://git.openjdk.org/jdk/pull/19965#discussion_r1662683507