Top Command Review

Recently in the search for some difficult diseases, the LIUNX related system commands are not very familiar with, or in a netizen to help, found that some of the top command I will not use,

So the top command to review. Use the screenshot below:

Parts of the situation:

3 Users,

Load average: Average length of task, three values 1, 5, 15 minutes ago to current average

tasks: There are 156 processes in total, 1 processes running, 154 processes in hibernation, 0 stop processes, 1 zombie processes

Display separately:

%sy kernel space consumes CPU percent,
%ni processes that have changed priority in the user process space consume CPU percentages,
%id Idle CPU percent,
%wa the percentage of CPU time waiting for input output (I/O),
%hi refers to the CPU processing hardware interrupt time,%SI refers to the CPU processing soft interrupt time,
%st is used with virtual CPUs to indicate the CPU time stolen by the virtual machine.

Above is the overview of top display.

Here is the top command line arguments,

-m parameter display effect:

-H parameter display effect (is to show thread execution of the current process)

Its contents are as follows:

12:38:33	Current time
Up 50days	System run time, format last: Min
1 user	Number of users currently logged in
Load average:0.06, 0.60, 0.48	System load, which is the average length of the task queue. Three values are 1 minutes, 5 minutes, and 15 minutes ago to the current average.

2. The second to third act process and CPU information

When you have more than one CPU, the content can be more than two lines. The contents are as follows:

tasks:29 Total	Total Processes
1 Running	Number of processes that are running
Sleeping	Number of processes to sleep
0 stopped	Number of processes stopped
0 Zombie	Number of zombie processes
Cpu (s): 0.3% US	Percentage of CPU consumed by user space
1.0% Sy	Kernel Footprint CPU percent
0.0% ni	Percentage of CPU in user process space that has changed priority
98.7% ID	Idle CPU percent
0.0% WA	Percentage of CPU time waiting for input output
0.0% hi
0.0% si

3. The 45th Act memory information.

The contents are as follows:

MEM:191272K Total	Total Physical Memory
173656k used	Total amount of physical memory used
17616k Free	Total Free Memory
22052k buffers	Amount of memory used as kernel cache
SWAP:192772K Total	Total Exchange Area
0k used	Total number of swap areas used
192772k Free	Total Free Swap Area
123988k Cached	The total number of buffered swap areas. The content in memory is swapped out to the swap area and then swapped into memory, but the used swap area has not been overwritten, which is the size of the swap area where the content already exists in memory . When the corresponding memory is swapped out again, you do not have to write to the swap area again.

Two. 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 the 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. A negative value indicates a high priority, and a positive value indicates a low priority
P	The last CPU used is meaningful only in a multiple CPU environment
%cpu	Percentage of CPU time that was last updated to now
Time	Total CPU time used by the process, in seconds
time+	Total CPU time used by the process, in units 1/100 seconds
%mem	Percentage of physical memory used by the process
Virt	Total amount of virtual memory used by the process, in kilobytes per KB. Virt=swap+res
SWAP	The amount of virtual memory that the process uses, swapped out in kilobytes.
Res	The amount of physical memory that the process uses, not swapped out, in kilobytes. Res=code+data
CODE	The amount of physical memory that the executable code occupies, in kilobytes
DATA	The amount of physical memory occupied by parts other than executable code (data segment + stack), in kilobytes
Shr	Shared memory size, per kb
Nflt	Number of page faults
Ndrt	The number of pages that were modified the last time it was written to.
S	Process status. D= an uninterrupted sleep state R= Run S= Sleep t= Tracking/Stopping z= Zombie Process
COMMAND	Command name/command line
Wchan	If the process is sleeping, the name of the system function in sleep is displayed
Flags	Task flags, reference sched.h