[lworld] RFR: 8375332: [lworld] JDI tests timeout with -XX:+UseCompactObjectHeaders on windows-x64

[Chris Plummer]

On Sat, 28 Feb 2026 02:03:02 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

> TestScaffold uses test arguments as additional options for debuggee process.
> Options like `-XX:+PrintInlineLayout',  `-XX:+PrintFlatArrayLayout` can cause significant debuggee output before TestScaffold connect to the debuggee and start to read it output. As a result internal output buffer fills and debuggee process hungs.
> The fix removes extra arguments used for experiments at test development.

test/jdk/com/sun/jdi/valhalla/FieldWatchpointsTest.java line 32:

> 30:  * @run main/othervm FieldWatchpointsTest
> 31:  *                   -XX:+UseArrayFlattening -XX:+UseFieldFlattening -XX:+UseAtomicValueFlattening -XX:+UseNullableValueFlattening
> 32:  *                   -XX:+UnlockDiagnosticVMOptions -XX:+PrintInlineLayout -XX:+PrintFlatArrayLayout

Do we really need to get rid of all of the options? Aren't `-XX:+PrintInlineLayout` and `-XX:+PrintFlatArrayLayout` the main culprits?

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PR Review Comment: https://git.openjdk.org/valhalla/pull/2184#discussion_r2867082393