First, system monitoring
1.top: Real-time display of resource usage for each process in the system, similar to the Task Manager for Windows.
1. The first line is the task queue information
12:38:33 |
Current time |
Up 50days |
System run time, format last: minutes |
1 user |
Number of currently logged on users |
Load average:0.06, 0.60, 0.48 |
System load. The three values were 1 minutes, 5 minutes, and 15 minutes ago to the present average. |
2. Second to third behavioral process and CPU information
tasks:29 Total |
Total number of processes |
1 Running |
Number of processes that are running |
Sleeping |
Number of processes for sleep |
0 stopped |
Number of processes stopped |
0 Zombie |
Number of zombie processes |
Cpu (s): 0.3% US |
Percentage of CPU occupied by user space |
1.0% Sy |
Percentage of CPU consumed by kernel space |
0.0% ni |
CPU percentage of processes that have changed priority in user process space |
98.7% ID |
Percentage of idle CPU |
0.0% WA |
Percentage of CPU time waiting for input and output |
0.0% hi |
Percent of CPU time consumed by hardware interrupts |
0.0% si |
Percentage of CPU time that software interrupts consume |
3.45th Behavior Memory information.
4. Process information
Column Name |
Meaning |
Pid |
Process ID |
PPID |
Parent Process ID |
Ruser |
Real User Name |
Uid |
User ID of the process owner |
USER |
User name of the process owner |
GROUP |
Group Name of Process owner |
Tty |
The terminal name of the startup process. Processes that are not started from the terminal are displayed as? |
PR |
Priority level |
NI |
Nice value. Negative values indicate high priority, positive values indicate low priority |
P |
Last CPU used, only meaningful in multi-CPU environment |
%cpu |
CPU time consumption percentage last updated to current |
Time |
Total CPU time used by the process, in seconds |
time+ |
Total CPU time used by the process, Unit 1/100 sec |
%MEM |
Percentage of physical memory used by the process |
VIRT |
The total amount of virtual memory used by the process, in kilobytes. Virt=swap+res |
SWAP |
The size, in kilobytes, of the virtual memory that the process is using, swapped out. |
Res |
The size, in kilobytes, of the physical memory that the process used and was not swapped out. Res=code+data |
CODE |
The amount of physical memory the executable code occupies, in kilobytes |
DATA |
The amount of physical memory that is used by parts other than executable code (data segment + stack), in kilobytes |
Shr |
Shared memory size, in kilobytes |
Nflt |
Number of page faults |
Ndrt |
The number of pages that were modified the last time it was written to. |
S |
Process state. d= non-disruptive sleep state R= Run S= Sleep t= Tracking/Stopping z= Zombie Process |
COMMAND |
Command name/command line |
Wchan |
If the process is sleeping, the system function name in sleep is displayed |
Flags |
Task Flag, reference sched.h |
Linux Basics (iii)