RFR: 8310031: Parallel: Implement better work distribution for large object arrays in old gen [v7]

Tue Sep 19 08:26:43 UTC 2023

On Mon, 18 Sep 2023 16:54:28 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

> Basically you need a 2nd card table to collect the dirty marks, don't you?

Yes, sth alone that line; that's what I meant by "Recording to-be-redirtied cards requires some extra memory".

> So the precise card marks are actually used with the proposed patch. In the worst case (only the first card of each stripe is dirty) this does not help though.

Yes, this is my understanding -- in some scenarios, it degenerates into imprecise card scanning. OTOH, parallel processing large-obj-array and precise card scanning are two orthogonal aspects anyway.

Using the latest revision, I don't observe any regression in the attached bms.

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PR Comment: https://git.openjdk.org/jdk/pull/14846#issuecomment-1725047188