RFR: 8257145: Performance regression with -XX:-ResizePLAB after JDK-8079555 [v2]

[Dongbo He]

> Hi,
> 
> this is the continuation of the review of the implementation for:
> 
> https://bugs.openjdk.java.net/browse/JDK-8257145

Dongbo He has updated the pull request incrementally with one additional commit since the last revision:

  store the "default size" for the PLAB in the PLABStats

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1474/files
  - new: https://git.openjdk.java.net/jdk/pull/1474/files/1f975aa3..04102cbc

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1474&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1474&range=00-01

  Stats: 11 lines in 5 files changed: 5 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1474.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1474/head:pull/1474

PR: https://git.openjdk.java.net/jdk/pull/1474