Linux View CPU Status

1, Htop

2. Top

Content Explanation:

PID: ID of the process
USER: Process Owner
PR: The priority level of the process, the smaller the higher the priority is executed
Ninice: Value
VIRT: Virtual memory consumed by the process
RES: The physical memory occupied by the process
SHR: Shared memory used by the process
S: The state of the process. s for hibernation, R for running, Z for Zombie, n for the process priority value is negative
%CPU: Process Consuming CPU utilization
%MEM: The percentage of physical memory and total memory used by the process
Time+: The total CPU time that is consumed after the process is started, which is the cumulative value of the CPU usage time.
Command: Process start name

3,Cat/proc/stat

4.

Pmap

Depending on the process, you can view the memory used by the process-related information (the process number can be viewed by PS) as follows:
$ pmap-d 5647

Ps

As shown in the following example:
$ ps-e-O ' pid,comm,args,pcpu,rsz,vsz,stime,user,uid ' where Rsz is the actual memory
$ ps-e-o ' pid,comm,args,pcpu,rsz,vsz,stime,user,uid ' |  grep Oracle | Sort-nrk

Where Rsz is the actual memory, the above example is implemented by memory sort, from large to small

View memory under Linux We generally use the free command:
[[email protected] tmp]# free
              total       used        free     shared    buffers     Cached
Mem:        3266180    3250004      16176           0     110652    2668236
-/+ buffers/cache:     471116    2795064
swap:      2048276      80160    1968116

Here is an explanation of these values:
Total: The amount of physical memory.
Used: How large is used.
Free: How much is available.
Shared: The total amount of memory shared by multiple processes.
Buffers/cached: The size of the disk cache.
Third line (-/+ buffers/cached):
Used: How large is used.
Free: How much is available.
There is not much to explain in line four.
Difference: The used/free of the second line (MEM) differs from the third row (-/+ Buffers/cache) used/free. The difference between the two is that the first line is from the OS point of view, because for the os,buffers/cached are all belong to be used, so his available memory is 16176KB, the used memory is 3250004KB, which includes, the kernel (OS) uses + Application (X, ORACLE,ETC) uses the +buffers+cached.
The third line refers to the application from the point of view, buffers/cached is equal to the availability of the application, because buffer/cached is to improve the performance of the file read, when the application needs to use memory, buffer/cached will be quickly recycled.
So from the application's point of view, available memory = System Free memory+buffers+cached.
As in the above example:
2795064=16176+110652+2668236

Next, explain when the memory will be exchanged, and by what side. When the available memory is less than the rated value, a meeting is exchanged.
How to see the rating:
Cat/proc/meminfo

[Email protected] tmp]# Cat/proc/meminfo
memtotal:3266180 KB
memfree:17456 KB
buffers:111328 KB
cached:2664024 KB
swapcached:0 KB
active:467236 KB
inactive:2644928 KB
hightotal:0 KB
highfree:0 KB
lowtotal:3266180 KB
lowfree:17456 KB
swaptotal:2048276 KB
swapfree:1968116 KB
Dirty:8 KB
writeback:0 KB
mapped:345360 KB
slab:112344 KB
committed_as:535292 KB
pagetables:2340 KB
vmalloctotal:536870911 KB
vmallocused:272696 KB
vmallocchunk:536598175 KB
hugepages_total:0
hugepages_free:0
hugepagesize:2048 KB

Results viewed with free-m:
[Email protected] tmp]# free-m
Total used free shared buffers Cached
mem:3189 3173 16 0 107 2605
-/+ buffers/cache:460 2729
swap:2000 78 1921

Linux View CPU Status