CPU, Memory usage in Linux from /proc
 

Hello,

I want to calculate '% of overall cpu usage' and '% of cpu used by a process' at the point of time. The computers is Linux (Assuming kernel above 2.4.3). So how should I calculate these?


And same for physical memory. I got the overall memory usage (from /proc/meminfo). But am not sure how to calculate it for a specific process. I calculated it for a number of process like:-

Took total memory size(MemTotal) form /proc/meminfo and RES size of process (VmRSS) from /proc/[process_id]/status

Then I am doing "(VmRSS/MemTotal)*100". Is it correct calculation for memory usage of a process? I think this will not add up the data/stack in the memory created by the process. So if I need to calculate total used memory of process what things I need from /proc?

I dont want to use 'top' command.

Sabyasachi.

So don't use the 'top' command. But do look at the source code for the 'top' command, to see how William LeFebvre did what you want to do.

http://www.fysh.org/~chris/top/

Hope this helps.