RFR: 8237842: Separate definitions for default cache line and padding sizes [v2]

[Aleksey Shipilev]

On Wed, 6 Dec 2023 16:47:59 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> My few cents about `x2` ;^) Looking on [JDK-8049737](https://bugs.openjdk.org/browse/JDK-8049737) changes and it is used to make sure that padding is greater then cache line. 

Yes, I think the intent was the same: cater for weird prefetcher interactions.

> In `padded.hpp` we have several macros `DEFINE_PAD_MINUS_SIZE` and `PADDED_END_SIZE` which calculate offset as (default_padding - size) .

Sure, I think this PR covers these paths too, or am I missing something there?

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PR Comment: https://git.openjdk.org/jdk/pull/16973#issuecomment-1843440916