RFR: 8310031: Parallel: Implement better work distribution for large object arrays in old gen [v5]

Tue Sep 12 08:08:38 UTC 2023

On Tue, 12 Sep 2023 07:38:53 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Note the ~2s increase in `GC(1)` young-gc pause.

My adhoc explanation would be the same as for the regression with just 1 gc thread running BigArrayInOldGenRR.java mentioned in the PR synopsis: splitting the array scan is less efficient. The cost for doing it can be higher then the gain if there is just 1 or 2 gc threads to benefit from the sharing. I'm still surprised that it happens with 2 gc threads. I will look into it after replying to all comments by Thomas and Roman.

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PR Comment: https://git.openjdk.org/jdk/pull/14846#issuecomment-1715210126