from jmap result, we can see, free heap size(up to 90%) exceed MaxHeapFreeRatio(40%), but jvm still not shrink.
this is jvm info: java.vm.name = OpenJDK 64-Bit Server VM java.vm.version = 25.352-b1 java.runtime.version = 1.8.0_352-b1
VM Flags: Non-default VM flags: -XX:CICompilerCount=2 -XX:CompressedClassSpaceSize=1065353216 -XX:ConcGCThreads=1 -XX:G1HeapRegionSize=1048576 -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=null -XX:InitialHeapSize=2577399808 -XX:InitialRAMPercentage=null -XX:MarkStackSize=4194304 -XX:MaxHeapFreeRatio=40 -XX:MaxHeapSize=6014631936 -XX:MaxMetaspaceSize=1073741824 -XX:MaxNewSize=3608150016 -XX:MaxRAMPercentage=null -XX:MetaspaceSize=536870912 -XX:MinHeapDeltaBytes=1048576 -XX:MinHeapFreeRatio=20 -XX:MinRAMPercentage=null -XX:+PrintGC -XX:+PrintGCDateStamps -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:SurvivorRatio=6 -XX:+UseAdaptiveSizePolicy -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseContainerSupport -XX:+UseG1GC -XX:+UseUTF8UTF16Intrinsics
Command line: -Duser.timezone=GMT+8 -Dfile.encoding=utf-8 -XX:+UseContainerSupport -XX:InitialRAMPercentage=30.0 -XX:MinRAMPercentage=70.0 -XX:MaxRAMPercentage=70.0 -XX:+UseAdaptiveSizePolicy -XX:MaxHeapFreeRatio=40 -XX:MinHeapFreeRatio=20 -XX:+UseG1GC -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/logs/my-heap-dump.hprof -XX:SurvivorRatio=6 -XX:MetaspaceSize=512m -XX:MaxMetaspaceSize=1024m -Xloggc:/logs/gc.log -XX:+PrintGCDetails -XX:+PrintGCDateStamps -Djava.security.egd=file:/dev/./urandom
-XX:+UseAdaptiveSizePolicy -XX:MaxHeapFreeRatio=40 -XX:MinHeapFreeRatio=20
with these arguments, I think jvm should shrink dynamicly according to heap idea memory.
