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

[Amit Kumar]

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

with 

fastlockbench:

|                 | Time (ns/op) [Average] | Performance Improvement |
|-----------------|-----------------------|-------------------------|
| With Patch (+LockingMode=2)        | 18.614                | -                       |
| Without Patch  | 19.116                | -                       |
| Improvement     | -                     | 2.63%                   |


Dacapo:

|                 | Time (msec)            | Performance Improvement |
|-----------------|-----------------------|-------------------------|
| Without Patch   | 118199                | -                       |
| With Patch (+LockingMode=2)      | 120213                | -                       |
| Improvement     | -                     | -1.70%                  |



 Renaissance-jmh (ms/op):
| Benchmark                                           | Without Patch | With Patch (+LockingMode=2) | Improvement (%) |
|-----------------------------------------------------|--------------|-------------|-----------------|
| o.r.actors.JmhAkkaUct.runOperation                  | 1349.563     | 1456.927    | -8.00           |
| o.r.actors.JmhReactors.runOperation                 | 10296.818    | 11605.138   | -12.82          |
| o.r.jdk.concurrent.JmhFjKmeans.runOperation         | 1145.668     | 1390.726    | -21.35          |
| o.r.jdk.concurrent.JmhFutureGenetic.runOperation    | 1952.648     | 1976.534    | -1.22           |
| o.r.jdk.streams.JmhParMnemonics.runOperation        | 2819.193     | 2801.261    | 0.64            |
| o.r.jdk.streams.JmhScrabble.runOperation            | 78.594       | 74.529      | 5.16            |
| o.r.rx.JmhRxScrabble.runOperation                   | 171.220      | 180.978     | -5.70           |
| o.r.scala.sat.JmhScalaDoku.runOperation             | 5841.122     | 3556.529    | 39.15           |
| o.r.scala.stdlib.JmhScalaKmeans.runOperation        | 199.683      | 183.357     | 8.18            |
| o.r.scala.stm.JmhPhilosophers.runOperation          | 14482.716    | 15834.972   | -9.32           |
| o.r.scala.stm.JmhScalaStmBench7.runOperation        | 1567.814     | 1716.439    | -9.46           |
| o.r.twitter.finagle.JmhFinagleChirper.runOperation  | 9477.834     | 9737.119    | -2.73           |
| o.r.twitter.finagle.JmhFinagleHttp.runOperation     | 4381.338     | 4681.571    | -6.85           |


These are the new results I'm getting, seems consistent as well. `-21.35 ` appears to be a lot but not sure if it's of observable category or not.

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

PR Comment: https://git.openjdk.org/jdk/pull/14414#issuecomment-1607892768