物理内存

• Structure is not freed from physical memory until you call the
  结构才能从物理内存中释放。
• A report server monitors the use of physical memory
  报表服务器监视的是物理内存的占用情况。
• Very little physical memory is available
  可用的物理内存非常少。
• Containing the number of bytes of physical memory for the computer
  包含计算机物理内存字节数的
• Gets the total amount of free physical memory for the computer
  获取计算机的空闲物理内存总量。
• When this number is larger than the amount of physical memory , the
  如果该数字大于物理内存量，则
• You also need enough free physical memory to run the jvm
  还需要有足够的空闲物理内存来运行jvm 。
• Is used to get the total physical memory
  在linux中，可以使用系统调用sysinfo来获取全部的物理内存：
• Plenty of physical memory is available
  可用的物理内存很多。
• Available physical memory is neutral
  可用的物理内存适中。