The mark phase took 422 ms, the sweepphase took 37 ms, and the compact phase took 0 ms.
mark阶段422 ms, sweep阶段37 ms, compact阶段0 ms。
2
In sweepphase, all the objects that have been allocated but are no longer referenced are identified.
在清除阶段，识别所有已经分配但不再被引用的对象。
3
In the sweepphase, the JVM goes through the heap and removes all the objects that still have the mark bit in place; these objects are no longer referenced or used.