Linux Top command

The top command is a common performance analysis tool under Linux that shows the resource usage of each process in the system in real time.

Top is a dynamic display process where the current state can be refreshed continuously with the user key. If the command is executed in the foreground, it will monopolize the foreground until the user terminates the program. More accurately, the top command provides real-time status monitoring of the system's processor. It will show the CPU's most "sensitive Task List. This command can be used by CPU. Memory usage and execution time to sort tasks, and many of the features of the command can be set through interactive commands or in personal customization files.

Top-14:25:37 up 1 day, 19:55, 8 users, load average:0.07, 0.12, 0.10
tasks:177 Total, 1 running, 176 sleeping, 0 stopped, 0 zombie
%CPU (s): 0.5 us, 0.5 sy, 0.0 ni, 99.0 ID, 0.0 wa, 0.0 hi, 0.0 si, 0.0th
KiB mem:1017356 Total, 934552 used, 82804 free, 14108 buffers
KiB swap:1038332 Total, 479540 used, 558792 free. 272768 Cached Mem
PID to Signal/kill [Default PID = 7]
PID USER PR NI VIRT RES SHR S%cpu%MEM time+ COMMAND
7 Root 0 0 0 0 S 1.0 0.0 0:29.67 rcu_sched
2621 hello1 0 309304 23264 10468 S 1.0 2.3 2:11.07 Compiz
13686 hello1 0 562744 91148 20172 S 1.0 9.0 0:21.82 Firefox
15975 Hello1 0 5424 1352 968 R 1.0 0.1 0:00.02 Top
1 Root 0 4464 1352 536 S 0.0 0.1 0:02.59 Init
2 Root 0 0 0 0 S 0.0 0.0 0:00.00 Kthreadd
3 Root 0 0 0 0 S 0.0 0.0 4:02.96 ksoftirqd/0
5 root 0-20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:+
8 Root 0 0 0 0 S 0.0 0.0 0:00.00 RCU_BH
9 Root RT 0 0 0 0 S 0.0 0.0 0:00.12 migration/0

The first line is the task queue information, the average load;

Second to third behavior process and CPU information when there are multiple CPUs, the content may be more than two lines.

45th Behavior Memory information, where buffer is used as the amount of RAM for the kernel cache, the cache buffers the total amount of swap, the contents of the memory are swapped out to the swap, and then swapped into memory, but the used swap is not yet overwritten, the value is that the content already exists in memory The size of the swap area. When the corresponding memory is swapped out again, it is no longer necessary to write to the swap area. Swap, swap area capacity;

US: Represents the percentage of CPU occupied in our space; SY: Represents the percentage of CPU occupied in the kernel space; ID: Represents the percentage of idle CPU; WA: Represents the percentage of CPU consumption waiting for input input.

Linux Top command