RFR: JDK-8274249: ZGC: Bulk free empty relocated pages [v6]

[王超]

> Similar to JDK-8255237, bulk free empty relocated pages can amortize the cost of freeing a page and speed up the relocation stage.
> 
> The following is the result of specjbb2015 after applying the patch (the tests turn off  the option`UseDynamicNumberOfGCThreads`): the average relocation time speeds up 14%, and the max relocation time speeds up 18%.
> 
> patch:
> [2021-09-18T13:11:51.736+0800][info][gc,stats    ]       Phase: Concurrent Relocate                           0.000 / 0.000       373.180 / 569.855     275.312 / 569.855     275.312 / 569.855     ms
> [2021-09-18T15:30:07.168+0800][info][gc,stats    ]       Phase: Concurrent Relocate                           0.000 / 0.000       381.266 / 577.812     277.272 / 577.812     277.272 / 577.812     ms
> [2021-09-18T17:37:56.305+0800][info][gc,stats    ]       Phase: Concurrent Relocate                           0.000 / 0.000       345.037 / 494.135     259.497 / 506.815     259.497 / 506.815     ms
> 
> 
> origin:
> [2021-09-18T01:01:32.897+0800][info][gc,stats    ]       Phase: Concurrent Relocate                           0.000 / 0.000       429.099 / 662.120     327.213 / 759.723     327.213 / 759.723     ms
> [2021-09-18T03:11:10.433+0800][info][gc,stats    ]       Phase: Concurrent Relocate                           0.000 / 0.000       413.014 / 613.035     307.625 / 613.035     307.625 / 613.035     ms
> [2021-09-18T05:21:12.743+0800][info][gc,stats    ]       Phase: Concurrent Relocate                           0.000 / 0.000       411.745 / 642.242     308.986 / 642.242     308.986 / 642.242     ms

王超 has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:

  Use dynamic allocated array instead of static variable

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5670/files
  - new: https://git.openjdk.java.net/jdk/pull/5670/files/d20be12b..b38e3ab1

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5670&range=05
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5670&range=04-05

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5670.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5670/head:pull/5670

PR: https://git.openjdk.java.net/jdk/pull/5670