问题
I can set the Java Heap Size minimum and maximum by passing the parameters -Xms and -Xmx, respectively.
I understand that the maximum flag is necessary to limit the space, but what's the reason for setting a minimum initial heap size? If the maximum is big enough, the space will increase? Or do i miss something?
回答1:
Minimun size is set so that the JVM doesn't have to "resize" the heap space if it starts off too small.
回答2:
Java will start with the minimum heap size and will try to avoid enlarging the heap by garbage collecting.
So if the steady-state memory size of your app is larger than the default heap minimum heap size, you may do a lot of pointless GC on the way to that size. Setting the min size to that size will avoid the pointless GC.
回答3:
You can set the minimum heap size if your application needs a certain amount to run. If you set the maximum heap size, the jvm isn't supposed to exceed it.
来源：https://stackoverflow.com/questions/8085949/whats-the-reason-to-set-a-minimal-java-heap-size