RFR: 8368740: Serial: Swap eden and survivor spaces position in young generation

Fri Sep 26 07:40:08 UTC 2025

Change the relative position of eden and survior spaces in young-gen so that eden can be expanded to fulfill allocation request in heap-near-full scenario. What is on master doesn't allow eden expansion if there is live objs inside from/to after full-gc.

Test: tier1-8

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Commit messages:
 - sgc-expand-allocate

Changes: https://git.openjdk.org/jdk/pull/27513/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27513&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368740
  Stats: 216 lines in 5 files changed: 64 ins; 61 del; 91 mod
  Patch: https://git.openjdk.org/jdk/pull/27513.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27513/head:pull/27513

PR: https://git.openjdk.org/jdk/pull/27513