RFR: 8323791: Parallel: Using non-atomic for live bytes update during Full GC [v2]

[Albert Mingkun Yang]

> Simple optimization to avoid atomic-operation during Full GC marking.
> 
> Test: Full GC pause length shows ~1% regresion when using single gc-thread and ~20% improvement when using multiple gc-threads using the attached program.

Albert Mingkun Yang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains one additional commit since the last revision:

  pgc-fullgc-livebyte

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17442/files
  - new: https://git.openjdk.org/jdk/pull/17442/files/bc881a83..51605b62

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17442&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17442&range=00-01

  Stats: 7376 lines in 251 files changed: 4497 ins; 1713 del; 1166 mod
  Patch: https://git.openjdk.org/jdk/pull/17442.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17442/head:pull/17442

PR: https://git.openjdk.org/jdk/pull/17442