RFR: 8317542: Specjvm::xml have scalability issue for high vCPU numbers [v2]

[Vladimir Ivanov]

> The synchronization block may be substituted by the 'volatile' variable smaller synchronization block.
> It reduce the total blocking time for the specjvm2008::xml.validation workload and improve the reported score.
> Scores for the 112vCPU on the with 28GB heap increased from 17915.83 to 22943.2.
> Unit tests was not affected:
> Test summary
> ==============================
>    TEST                                              TOTAL  PASS  FAIL ERROR
>    jtreg:test/jaxp                                     516   516     0     0
>    jtreg:test/jdk/javax/xml                             70    70     0     0
> ==============================
> TEST SUCCESS
> 
> The tier1 is OK too.

Vladimir Ivanov has updated the pull request incrementally with one additional commit since the last revision:

  8317542: Specjvm::xml have scalability issue for high vCPU numbers

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/21815/files
  - new: https://git.openjdk.org/jdk/pull/21815/files/b6894386..6bf932ab

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21815&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21815&range=00-01

  Stats: 19 lines in 1 file changed: 1 ins; 15 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/21815.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21815/head:pull/21815

PR: https://git.openjdk.org/jdk/pull/21815