RFR: 8339573: Update CodeCacheSegmentSize and CodeEntryAlignment for ARM

[Boris Ulasevich]

On Mon, 9 Sep 2024 19:12:35 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> > Hotspot performance tests with -XX:CodeCacheSegmentSize=64 and -XX:CodeEntryAlignment=16 options showed the following results:
> 
> Which of these two flags setting improved performance most?

There is a high noise in the benchmark. With 1K of iterations on Neoverse V2 machine the result is:


vm options  | ms/op | % | cache-misses (M) | group0-code_sparsity (K) | L1-icache-load-misses:u (M)
-- | -- | -- | -- | -- | --
default | 635.574 |   | 7193 | 18152 | 10111
CodeEntryAlignment | 633.961 | -0.25 | 7177 | 18156 | 10334
CodeCacheSegmentSize | 633.041 | -0.15 | 7187 | 17919 | 10081
both | 631.687 | -0.21 | 7167 | 17796 | 10287

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

PR Comment: https://git.openjdk.org/jdk/pull/20864#issuecomment-2339014367