1, for cpu occupancy
[Root @ localhost utx86] # top-n 1 | grep Cpu
Cpu (s): 1.9% us, 1.3% sy, 0.0% ni, 95.9% id, 0.6% wa, 0.1% hi, 0.2% si, 0.0% st
Explained: 1.9% us is the user take up cpu case
1.3% sy, is the system is using cpu case
2, access the memory occupancy
[Root @ localhost utx86] # top-n 1 | grep Mem
Mem: 2066240k total, 1515784k used, 550456k free, 195336k buffers
3, Linux system, the average load (load average)
Members might have noticed that when the implementation of the Linux system uptime, w and the top three command. In the end the results of the first line will have a load average, and will be followed by three numbers followed, and this is what we are saying today, the system load average.
Average system load definition: at a specific time interval, the average run queue process number. If a process meets the following conditions, then the queue will be in operation:
1. Without waiting for I / O operation results
2. Not to enter the wait state (that is not called 'wait')
3. Not stop (for example: waiting for termination)
For example, we execute the command uptime.
ff @: ~ $ uptime
09:59:28 up 1:13, 3 users, load average: 1.42, 1.38, 1.38
The three figures represent the back of the system in the last 1,5,15 minutes, the average process in the run queue number. In general, as long as each CPU, the number of currently active process that is not greater than 3 on a good performance; if the number of tasks greater than 5 CPU that the machine's performance on a serious issue.
Suppose the above is a dual-core CPU, uptime output, then the number of each CPU on the current task is: 1.42 / 2 = 0.71.