RFR: 8308479: [s390x] Implement alternative fast-locking scheme [v8]

[Kennke, Roman]

FWIW, I found many of the renaissance benchmarks quite noisy. Might be worth watching them closely, and consider ramping up number of iterations *and* forks. (Also, I found using the jmh-wrapped version much easier to deal with, with that you can achieve the increased iterations and forks with simple -i -wi and -f options)



> Am 07.09.2023 um 22:10 schrieb Coleen Phillimore <coleenp at openjdk.org>:
> 
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> 
> On Fri, 23 Jun 2023 05:44:04 GMT, Amit Kumar <amitkumar at openjdk.org> wrote:
> 
>>> This PR implements new fast-locking scheme for s390x. Additionally few parameters have been renamed to be in sync with PPC.
>>> 
>>> Testing done (for release, fastdebug and slowdebug build):
>>> All `test/jdk/java/util/concurrent` test with parameters:
>>> * LockingMode=2
>>> * LockingMode=2 with -Xint
>>> * LockingMode=2 with -XX:TieredStopAtLevel=1
>>> * LockingMode=2 with -XX:-TieredCompilation
>>> 
>>> Result is consistently similar to Aarch(MacOS) and PPC, All of 124 tests are passing except `MapLoops.java` because in the 2nd part for this testcase, jvm starts with `HeavyMonitors` which conflict with `LockingMode=2`
>>> 
>>> BenchMark Result for Renaissance-jmh:
>>> 
>>> | Benchmark                                | Without fastLock (ms/op) | With fastLock (ms/op) | Improvement |
>>> |------------------------------------------|-------------------------|----------------------|-------------|
>>> | o.r.actors.JmhAkkaUct.runOperation        | 1565.080                | 1365.877             | 12.70%      |
>>> | o.r.actors.JmhReactors.runOperation       | 9316.972                | 10592.982            | -13.70%     |
>>> | o.r.jdk.concurrent.JmhFjKmeans.runOperation | 1257.183                | 1235.530             | 1.73%       |
>>> | o.r.jdk.concurrent.JmhFutureGenetic.runOperation | 1925.158                | 2073.066             | -7.69%      |
>>> | o.r.jdk.streams.JmhParMnemonics.runOperation | 2746.664                | 2836.085             | -3.24%      |
>>> | o.r.jdk.streams.JmhScrabble.runOperation   | 76.774                  | 74.239               | 3.31%       |
>>> | o.r.rx.JmhRxScrabble.runOperation          | 162.270                 | 167.061              | -2.96%      |
>>> | o.r.scala.sat.JmhScalaDoku.runOperation    | 3333.711                | 3271.078             | 1.88%       |
>>> | o.r.scala.stdlib.JmhScalaKmeans.runOperation | 182.746                 | 182.153              | 0.33%       |
>>> | o.r.scala.stm.JmhPhilosophers.runOperation | 15003.329               | 13396.921            | 10.57%      |
>>> | o.r.scala.stm.JmhScalaStmBench7.runOperation | 1669.090                | 1579.900             | 5.34%       |
>>> | o.r.twitter.finagle.JmhFinagleChirper.runOperation | 9601.963                | 10034.404            | -4.52%      |
>>> | o.r.twitter.finagle.JmhFinagleHttp.runOperation | 4403.725                | 4746.707             | -7.79%      |
>>> 
>>> 
>>> DaCapo Benchmark Result:
>>> 
>>> | Benchmark                | Without fast lock (msec) | With fast lock (msec) | Improvement |
>>> |--...
>> 
>> Amit Kumar has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>  suggestions from Martin
> 
> We are considering making Fast Locking on by default for Oracle supported platforms.  Have these performance concerns been addressed?
> 
> -------------
> 
> PR Comment: https://git.openjdk.org/jdk/pull/14414#issuecomment-1710701169



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