????OpenJDK 8 ?ж??? GC??Garbage Collector???????? Parallel GC??CMS ?? G1????????????????????? Java 9 ?н? Java 8 ???? GC ?? Parallel GC ??? G1 ?????????飩??????????????????????л???????
??????????????
???????????????????Σ??????ò????VM??????-XX:+UseSerialGC?? -XX:+UseParallelGC?? -XX:+UseConcMarkSweepGC?? -XX:ParallelCMSThreads=2?? -XX:ParallelCMSThreads=4?? -XX:+UseG1GC????
??????????д?????55?????
????????VM??????-Xmx2048M -server
????OpenJDK?汾??1.8.0_51??????μ?汾??
?????????Linux version 4.0.4-301.fc22.x86_64
?????????Intel? Core? i7-4790 CPU @ 3.60GHz
???????????13???OptaPlanner??滮???????????????????5??????30??????JVM???????????????
????????滮?????漰 IO ???????????????????????????????????????? CPU ????????????????????????????????GC ?????????Щ????
??????????????????????????÷???????á????????????滮????????????????С????????漰????????????????????????????????????????
???????????????????????Щ??????????????????й???????????????? GeneralOptaPlannerBenchmarkApp??
?????????????
??????н??
??????????????????????? GC ?? Java 8 ??? GC??Parallel GC???????????

???????????????????Parallel GC???????
?????????????????

?????????????????

????Java 9 ??????? G1 ??
????????????????? OpenJDK9 ???????????? G1 ?????? GC??????????????????飺
????G1 ?????????17.60%
????G1 ????????????????????????
??????????????Machine Reassignment B10???￡????????????????????G1 ????34.07%??
??????????????????????????ò??????? GC?????????????????????????
??????????棬??????????????????
????G1 ????? GC ?????????????????????????????Щ??????????????????GC ??????????????
????????????????????????????????????н???????????????????????????????????????
????G1 ??????????????? 6GB??????λ????????????? 2GB???????????????Machine Reassignment B10??????????????檔
??????????????? OpenJDK ????????е??????????????????????????????????????????棨????????????????????????????GC????????????????????????????????????
????????
?????? Java 8 ?У??? OptaPlanner ???????????? GC??Parallel GC???????????????