我有一个 linux 服务器，它一直用完所有内存，我看不到正在使用它的内容。运行top给出以下响应：
Tasks: 103 total, 1 running, 102 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 8000452k total, 6336612k used, 1663840k free, 298784k buffers
Swap: 2187256k total, 0k used, 2187256k free, 4850536k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1847 mwl 20 0 1604m 688m 10m S 0 8.8 1:18.02 java
767 mysql 20 0 301m 101m 7424 S 0 1.3 0:33.11 mysqld
970 www-data …