%CPU in a multiprocessor system

[gab_in]

Hi,

In some of our cases the %CPU exceeds 100%.Can you please clarify the following queries?

1: What does a % CPU of 450 mean in a multiprocessor system ? The process is using 100% of 4 CPU & 50% of 1 CPU ?

2: What is the maximum value that can be seen in % CPU ?

Thanks in advance
Gab

[gab_in]

would like to update here that this question I am asking about the 'top' output and colume '%CPU'.

Waiting for your reponse.

[Gokul Chandola]

Hi,
There is simple meaning following your 4 CPU utilisation is fully utilized and 1 CPU is 50% Utilized, (there is 5 CPU) for A PERTICULAR TIME.
100% of 4 CPU & 50% of 1 CPU.

You Can check the processes running with "ps" command.

"TOP" is the best monitoring command for Utilization, but you can see the logs for more detail.

Regards,
Gokul Chandola

[Duncan Edmonstone]

>> 1: What does a % CPU of 450 mean in a multiprocessor system ? The process is using 100% of 4 CPU & 50% of 1 CPU ?

Not necessarily... it could mean 9 CPUs are all 50% utilised. It's just a simple addition of the % utilisation of each CPU in the system

>> 2: What is the maximum value that can be seen in % CPU ?

(Num CPUs in System) * 100%

So if your system has 8 CPUs the max is 800%

HTH

Duncan

[Dennis Handly]

And to get more than 100%, the process would have to be using threads.