RFR: 8357959: (bf) ByteBuffer.allocateDirect initialization can result in large TTSP spikes [v2]

Wed May 28 16:43:50 UTC 2025

On Wed, 28 May 2025 16:24:13 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Thanks for the insight on value of chunk size. And agreed on static final part, I’ve made it a `private static final `constant
>
>> In the past, the bulk put/get when swapping also used 1MB as the threshold because of TTSP
> 
> Oh, TIL. Do you have a pointer where that was? I searched around and cannot find it. We should probably put the constant in the similar place.

We have https://github.com/openjdk/jdk8u/blob/master/jdk/src/share/classes/java/nio/Bits.java#L776-L779, at least. Not sure if there are others.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25487#discussion_r2112333241