* if you want to plug in and go, use these flags:
-XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+AlwaysActAsServerClassMachine -XX:+AlwaysPreTouch -XX:+DisableExplicitGC -XX:NmethodSweepActivity=1 -XX:ReservedCodeCacheSize=400M -XX:NonNMethodCodeHeapSize=12M -XX:ProfiledCodeHeapSize=194M -XX:NonProfiledCodeHeapSize=194M -XX:-DontCompileHugeMethods -XX:+PerfDisableSharedMem -XX:+UseFastUnorderedTimeStamps -XX:+EagerJVMCI -Dgraal.UsePriorityInlining=true -Dgraal.Vectorization=true -Dgraal.OptDuplication=true -Dgraal.DetectInvertedLoopsAsCounted=true -Dgraal.LoopInversion=true -Dgraal.VectorizeHashes=true -Dgraal.EnterprisePartialUnroll=true -Dgraal.VectorizeSIMD=true -Dgraal.StripMineNonCountedLoops=true -Dgraal.SpeculativeGuardMovement=true -Dgraal.TuneInlinerExploration=1 -Dgraal.LoopRotation=true -Dgraal.OptWriteMotion=true -Dgraal.CompilerConfiguration=enterprise -XX:+UseG1GC -XX:MaxGCPauseMillis=37 -XX:+PerfDisableSharedMem -XX:G1HeapRegionSize=16M -XX:G1NewSizePercent=23 -XX:G1ReservePercent=20 -XX:SurvivorRatio=32 -XX:G1MixedGCCountTarget=3 -XX:G1HeapWastePercent=20 -XX:InitiatingHeapOccupancyPercent=10 -XX:G1RSetUpdatingPauseTimePercent=0 -XX:MaxTenuringThreshold=1 -XX:G1SATBBufferEnqueueingThresholdPercent=30 -XX:G1ConcMarkStepDurationMillis=5.0 -XX:GCTimeRatio=99 -XX:G1ConcRefinementServiceIntervalMillis=150 -XX:G1ConcRSHotCardLimit=16 -XX:AllocatePrefetchStyle=3

* if you know how to enable usage of large memory pages, add these (windows):
* reference: https://kstefanj.github.io/2021/05/19/large-pages-and-java.html
-XX:+UseLargePages -XX:LargePageSizeInBytes=2m
* on linux
-XX:+UseTransparentHugePages

* if you have little RAM to play with, try these flags instead:
-XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+AlwaysActAsServerClassMachine -XX:+AlwaysPreTouch -XX:+DisableExplicitGC -XX:-DontCompileHugeMethods -XX:+PerfDisableSharedMem -XX:+UseFastUnorderedTimeStamps -XX:+EagerJVMCI -Dgraal.UsePriorityInlining=true -Dgraal.Vectorization=true -Dgraal.OptDuplication=true -Dgraal.DetectInvertedLoopsAsCounted=true  -Dgraal.LoopInversion=true -Dgraal.VectorizeHashes=true -Dgraal.EnterprisePartialUnroll=true -Dgraal.VectorizeSIMD=true -Dgraal.StripMineNonCountedLoops=true  -Dgraal.SpeculativeGuardMovement=true -Dgraal.TuneInlinerExploration=1 -Dgraal.LoopRotation=true -Dgraal.OptWriteMotion=true -Dgraal.CompilerConfiguration=enterprise -XX:+UseG1GC -XX:MaxGCPauseMillis=130 -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=28 -XX:G1HeapRegionSize=16M -XX:G1ReservePercent=20 -XX:G1MixedGCCountTarget=3 -XX:InitiatingHeapOccupancyPercent=10 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=0 -XX:SurvivorRatio=32 -XX:MaxTenuringThreshold=1 -XX:G1SATBBufferEnqueueingThresholdPercent=30 -XX:G1ConcMarkStepDurationMillis=5.0 -XX:G1ConcRefinementServiceIntervalMillis=150 -XX:G1ConcRSHotCardLimit=16 -XX:AllocatePrefetchStyle=3

* the following were listed as "experimental" but could help performance.
-Dgraal.UsePriorityInlining=true -Dgraal.Vectorization=true -Dgraal.OptDuplication=true -Dgraal.DetectInvertedLoopsAsCounted=true -Dgraal.LoopInversion=true -Dgraal.VectorizeHashes=true -Dgraal.EnterprisePartialUnroll=true -Dgraal.VectorizeSIMD=true -Dgraal.StripMineNonCountedLoops=true -Dgraal.SpeculativeGuardMovement=true -Dgraal.TuneInlinerExploration=1 -Dgraal.LoopRotation=true -Dgraal.OptWriteMotion=true -Dgraal.CompilerConfiguration=enterprise