RFR: 8306920: G1: Calculate garbage bytes for evacuation failed regions from marked live bytes

Thu May 25 11:59:55 UTC 2023

On Wed, 24 May 2023 09:38:23 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> but currently is calculated in post evacuation phase 2

Which task specifically in phase 2? I thought it's `RestoreRetainedRegionsTask` that calculates garbage-bytes/live-bytes, which lives in phase 1.

> there is no (problematic) overlap with its use during marking

Even if it's correct, I find it a bit hacky to reuse marking-related data structure like this, `add_to_liveness` uses `_mark_stats_cache`.

(`G1CMBitMap` is also used outside conc-mark, but I'd say that it should be brought up to the heap-level; bitmap, mirroring the whole heap, is not really tied to conc-mark.)

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PR Comment: https://git.openjdk.org/jdk/pull/14118#issuecomment-1562776398