[lilliput-jdk17u:lilliput] RFR: 8319799: Recursive lightweight locking: x86 implementation [v2]

[Roman Kennke]

On Thu, 18 Apr 2024 13:51:32 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

>> Backports https://github.com/openjdk/jdk/commit/7f6bb71eb302e8388c959bdaa914b758a766d299
>> 
>> Implements the x86_64 parts of recursive lightweight locking.
>> 
>> Unclean, mostly because of biased locking.
>
> Roman Kennke has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove superfluous loading of mark-word

> Looks okay, but I have a minor comment.
> 
> It looks like `lightweight_lock` does not need pre-loaded header anymore. Yet, some uses of it still load the header. I see the original commit moved header loading to `!LM_LIGHTWEIGHT` branches: [openjdk/jdk at 7f6bb71#diff-4ce1e880593668bead8462bc6b550bb21e11ad7dd1d8a43d77d5dac7510ba9c3L63](https://github.com/openjdk/jdk/commit/7f6bb71eb302e8388c959bdaa914b758a766d299#diff-4ce1e880593668bead8462bc6b550bb21e11ad7dd1d8a43d77d5dac7510ba9c3L63)
> 
> Seems like at least here we load the `hdr`: https://github.com/openjdk/lilliput-jdk17u/pull/84/files#diff-4ce1e880593668bead8462bc6b550bb21e11ad7dd1d8a43d77d5dac7510ba9c3R73-R74

Indeed, good catch. I removed that extra load and checked other places for similar oversights, but everything else seems ok.

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PR Comment: https://git.openjdk.org/lilliput-jdk17u/pull/84#issuecomment-2063935681