Search dba-db2.com
*Use the Comments section for questions
Recent Posts
Linux top greater than 100 percent - CPU
14 October,2013 by Tom Collins
Question: I was using the Linux top command to monitor the CPU activity on a Linux server hosting. To my surprise , I saw the CPU at 202% - what?! How can this be?
top - 16:45:37 up 127 days, 7:27, 1 user, load average: 2.21, 2.23, 2.23 Tasks: 153 total, 1 running, 152 sleeping, 0 stopped, 0 zombie Cpu(s): 24.6% us, 1.1% sy, 0.0% ni, 73.4% id, 1.0% wa, 0.0% hi, 0.0% si Mem: 24684584k total, 16883612k used, 7800972k free, 608548k buffers Swap: 12586936k total, 78384k used, 12508552k free, 14552460k cached PID USER PR NI %CPU TIME+ %MEM VIRT RES SHR S COMMAND 10257 db2inst1 25 0 202 16895:27 39.6 14.2g 9.3g 9.3g S db2sysc
Answer: It is a useful command , but the high number is supposed to be the aggregate of all the cores.
The Linux top command offers a continuous, real time look at the CPU activity.
To see a detailed core breakdown , you’ll need to type “1” after you’ve executed the command “top” .
For example , you may see 202% , but once you’ve typed “1” , you may see 8 cores – with various usage levels at below 100% or lower
top - 13:36:43 up 129 days, 4:19, 1 user, load average: 2.13, 2.16, 2.20 Tasks: 155 total, 1 running, 154 sleeping, 0 stopped, 0 zombie Cpu0 : 0.3% us, 0.3% sy, 0.0% ni, 99.3% id, 0.0% wa, 0.0% hi, 0.0% si Cpu1 : 0.0% us, 0.3% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si Cpu2 : 0.0% us, 0.0% sy, 0.0% ni, 99.0% id, 1.0% wa, 0.0% hi, 0.0% si Cpu3 : 9.0% us, 0.7% sy, 0.0% ni, 90.0% id, 0.3% wa, 0.0% hi, 0.0% si Cpu4 : 0.0% us, 0.0% sy, 0.0% ni, 100.0% id, 0.0% wa, 0.0% hi, 0.0% si Cpu5 : 0.3% us, 0.0% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si Cpu6 : 96.3% us, 3.7% sy, 0.0% ni, 0.0% id, 0.0% wa, 0.0% hi, 0.0% si Cpu7 : 96.0% us, 3.0% sy, 0.0% ni, 1.0% id, 0.0% wa, 0.0% hi, 0.0% si Mem: 24684584k total, 15487164k used, 9197420k free, 648812k buffers Swap: 12586936k total, 78704k used, 12508232k free, 12221548k cached PID USER PR NI %CPU TIME+ %MEM VIRT RES SHR S COMMAND 10257 db2inst1 25 0 209 21499:35 40.2 14.2g 9.5g 9.4g S db2sysc
Read More Linux and CPU
Display Linux CPU information - DBA DB2
Database tuning and Operating System Tuning - DBA DB2
Verify your Comment
Previewing your Comment
This is only a preview. Your comment has not yet been posted.
As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.
Having trouble reading this image? View an alternate.
dba-db2.com | DB2 Performance Tuning | DBA DB2:Everything | FAQ | Contact | Copyright
Posted by: |