= Java =

== HeapSize ==

https://www.journaldev.com/2856/java-jvm-memory-model-memory-management-in-java

[[Image(https://cdn.journaldev.com/wp-content/uploads/2014/05/Java-Memory-Model-1024x425.png)]]

* 系統預設值
{{{
~$ java -XX:+PrintFlagsFinal -version | grep HeapSize
    uintx ErgoHeapSizeLimit                         = 0                                   {product}
    uintx HeapSizePerGCThread                       = 87241520                            {product}
    uintx InitialHeapSize                          := 197132288                           {product}
    uintx LargePageHeapSizeThreshold                = 134217728                           {product}
    uintx MaxHeapSize                              := 3149922304                          {product}
java version "1.8.0_74"
Java(TM) SE Runtime Environment (build 1.8.0_74-b02)
Java HotSpot(TM) 64-Bit Server VM (build 25.74-b02, mixed mode)
}}}