[master] RFR: Lilliput om world

[Axel Boldt-Christmas]

On Fri, 31 May 2024 20:46:25 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> Added a diagnostic option UseObjectMonitorTable to maintain performance of LM_LIGHTWEIGHT locking which is now defaulted to on in mainline.
> 
> Incorporated Axel's patch to support other platforms with UseObjectMonitorTable (branch to slow path).
> 
> Tested tier 1-4 on x86.  Fails both versions of this test, but not locally:  runtime/cds/TestDefaultArchiveLoading.java.
> 
> tier1 aarch64 in progress.

I like this change and the restructuring. 👍

src/hotspot/share/runtime/synchronizer.cpp line 427:

> 425:       // Recursive lock successful.
> 426:       current->inc_held_monitor_count();
> 427:       return true;

This needs a CacheSetter

Suggestion:

      CacheSetter cache_setter(current, lock);
  
      // Recursive lock successful.
      current->inc_held_monitor_count();
      return true;

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

PR Review: https://git.openjdk.org/lilliput/pull/181#pullrequestreview-2093593729
PR Review Comment: https://git.openjdk.org/lilliput/pull/181#discussion_r1624279436