On Thu, 20 Aug 2026 14:13:27 GMT, Fredrik Bredberg <[email protected]> 
wrote:

> This PR is a follow-up to 
> [JDK-8389325](https://bugs.openjdk.org/browse/JDK-8389325) ("Remove the 
> UseObjectMonitorTable flag and related code"). It:
> - Removes obsolete mark-word and monitor-pointer support.
> - Removes displaced-mark related code in garbage collectors (G1, Parallel GC 
> and Shenandoah).
> - Renames UseObjectMonitorTableTest to ObjectMonitorTableTest.
> - Addresses all the leftover review comments from 
> [JDK-8389325](https://bugs.openjdk.org/browse/JDK-8389325).
> 
> Passes tier1-5 tests successfully on supported platforms.
> 
> ---------
> - [x] I confirm that I make this contribution in accordance with the [OpenJDK 
> Interim AI Policy](https://openjdk.org/legal/ai).

Some questions and suggested additions.

src/hotspot/share/oops/markWord.cpp line 40:

> 38:     // have to check has_monitor() before is_locked()
> 39:     // Valhalla: inline types/arrays can't be monitored
> 40:     st->print(" monitor(" INTPTR_FORMAT ")", value());

But the monitor isn't the value now. Shouldn't this just be removed?  We don't 
want printing to search the table.

src/hotspot/share/runtime/objectMonitor.hpp line 236:

> 234:   uintptr_t           metadata() const;
> 235:   void                set_metadata(uintptr_t value);
> 236:   volatile uintptr_t* metadata_addr();

If I remember this correctly metadata could be two different things, but with 
the lock in the markWord gone, it can now only be one thing.  But I guess that 
one thing is the hash code as uintptr_t ?
Is metadata_addr() used?

src/hotspot/share/runtime/objectMonitor.inline.hpp line 88:

> 86:   set_metadata(hdr.value());
> 87: }
> 88: 

Is there also a set_metadata() that should be removed?

-------------

PR Review: https://git.openjdk.org/jdk/pull/32471#pullrequestreview-4995670129
PR Review Comment: https://git.openjdk.org/jdk/pull/32471#discussion_r3832190455
PR Review Comment: https://git.openjdk.org/jdk/pull/32471#discussion_r3833133580
PR Review Comment: https://git.openjdk.org/jdk/pull/32471#discussion_r3833136505

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