On Tue, 11 Aug 2026 08:44:57 GMT, Fredrik Bredberg <[email protected]> wrote:
>> The main objectives for this PR are: >> 1) Compact Object Headers needs the Object Monitor Table to work. >> 2) Both Compact Object Headers >> ([JDK-8360700](https://bugs.openjdk.org/browse/JDK-8360700)) and Object >> Monitor Table ([JDK-8379782](https://bugs.openjdk.org/browse/JDK-8379782)) >> are now enabled by default. >> 3) If we always use the Object Monitor Table, we will free up lots of bits >> in the markword, that could be of use to others (read GC). >> 4) If we don't need to maintain any "monitor pointer in the mark word" >> code, we will simplify the code base. >> >> Therefore this PR will remove the `UseObjectMonitorTable` flag and related >> code. >> >> Note that this PR only removes the most obvious use of the >> `UseObjectMonitorTable` in the code base. This is to ease the burden on the >> reviewers. [JDK-8389938](https://bugs.openjdk.org/browse/JDK-8389938) has >> been created to finalize the work by removing the less obvious code, like no >> longer used mark word code in different GCs. >> >> The code has passed tier1-7 testing on supported platforms and smoke testing >> using QEMU on `RISC-V`, `PowerPC` and `s390`. >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Fredrik Bredberg has updated the pull request with a new target base due to a > merge or a rebase. The incremental webrev excludes the unrelated changes > brought in by the merge/rebase. The pull request contains three additional > commits since the last revision: > > - Updated after review > - Merge branch 'master' into 8389325_remove_use_object_monitor_table_flag > - 8389325: Remove the UseObjectMonitorTable flag and related code I found a couple more things to remove. src/hotspot/share/runtime/synchronizer.cpp line 2174: > 2172: if (!UseObjectMonitorTable) { > 2173: // Do the old inflate and enter. > 2174: monitor = inflate_into_object_header(object, cause, locking_thread, > current); I think you can remove the method inflate_into_object_header since it was added for the non-OMT case. src/hotspot/share/runtime/synchronizer.cpp line 2207: > 2205: } > 2206: > 2207: ObjectMonitor* ObjectSynchronizer::read_monitor(markWord mark) { Shouldn't this version of read_monitor be deleted too? ------------- Changes requested by coleenp (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/32257#pullrequestreview-4905704683 PR Review Comment: https://git.openjdk.org/jdk/pull/32257#discussion_r3757511704 PR Review Comment: https://git.openjdk.org/jdk/pull/32257#discussion_r3757527996
