RFR: 8336685: Shenandoah: Remove experimental incremental update mode [v4]

[Y. Srinivas Ramakrishna]

On Thu, 25 Jul 2024 21:39:06 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> We've reason to believe that this mode is very rarely used and its maintenance has become a burden for future development.
>> 
>> ## Testing
>> * hotspot_gc_shenandoah
>> * dacapo
>> * diluvian
>> * extremem
>> * hyperalloc
>> * specjbb2015
>> * specjvm2008
>
> William Kemper 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 eight additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'openjdk/master' into remove-incremental-update-mode
>  - Simplify final mark now that incremental update mode is removed
>  - Remove unintentional new line
>  - Remove last vestiges of incremental update mode
>  - Missed test, remove actual IU barrier flag
>  - Remove missed iu_barrier usages for C1
>  - Update test (all barriers can be enabled now for all modes)
>  - WIP: Remove incremental update mode

I'd left my review comments instead of flushing them yesterday. Not sure if they are still relevant, but here they go... fwiw.

src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp line 339:

> 337:   product(bool, ShenandoahIUBarrier, false, DIAGNOSTIC,                     \
> 338:           "Turn on/off I-U barriers barriers in Shenandoah")                \
> 339:                                                                             \

Not your change, but these doc comments should really say `"Enable blah-blah ..."` rather than `"Turn on/off blah-blah..."`.

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

PR Review: https://git.openjdk.org/jdk/pull/20316#pullrequestreview-2198135931
PR Review Comment: https://git.openjdk.org/jdk/pull/20316#discussion_r1690703426