RFR: 8370947: Mitigate Neoverse-N1 erratum 1542419 negative impact on GCs and JIT performance [v13]

[Axel Boldt-Christmas]

On Wed, 3 Dec 2025 16:00:05 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Evgeny Astigeevich has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 19 commits:
>> 
>>  - Fix linux-cross-compile build aarch64
>>  - Merge branch 'master' into JDK-8370947
>>  - Remove trailing whitespaces
>>  - Add support of deferred icache invalidation to other GCs and JIT
>>  - Add UseDeferredICacheInvalidation to defer invalidation on CPU with hardware cache coherence
>>  - Add jtreg test
>>  - Fix linux-cross-compile aarch64 build
>>  - Fix regressions for Java methods without field accesses
>>  - Fix code style
>>  - Correct ifdef; Add dsb after ic
>>  - ... and 9 more: https://git.openjdk.org/jdk/compare/3d54a802...4b04496f
>
> src/hotspot/share/asm/codeBuffer.cpp line 939:
> 
>> 937:     // Move all the code and relocations to the new blob:
>> 938:     relocate_code_to(&cb);
>> 939:   }
> 
> Here and later, the preferred style is:
> 
> Suggestion:
> 
>   // Move all the code and relocations to the new blob:
>   {
>     ICacheInvalidationContext icic(ICacheInvalidation::NOT_NEEDED);
>     relocate_code_to(&cb);
>   }

Go ahead and use @shipilev suggested change. Following the code style of the surrounding code is usually my preference as well. 

_The style comments we had earlier all applied to the ZGC code which has a certain style._

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PR Review Comment: https://git.openjdk.org/jdk/pull/28328#discussion_r2587712509