assign one process to one core and how calculate runtime for process

Hi guys,

excuse me for my bad english.
:))
my OS: ubuntu
2 question:
1.How I can assign a process to one core?

2. How I can calculate runtime for a process, but my concern is other process interrupt CPU and i can't calculate real runtime.

thanks

When a process is suspended because of scheduling, when its next time slice comes up, it will be reassigned to the next available core; however, you can set the affinity of a process to a specific CPU or core. Here is a link with information that may help: Linux Setting processor affinity for a certain task or process