To know the processes that make intensive use of the CPU or memory, we can use the TOP program:

top - display Linux processes
It’s good to know the priority list first:
+ HIGH PRIORITY - LOW PRIORITY |----------|----------|----------|----------|----------|----------| nice value -20 -10 -5 0 5 10 19
renice for running process
To adjust the priority(PR) of a running process, either increase or decrease, you must alter the value (NI) with renice command:
// for example, we open gedit editor and check the process with top: $ gedit

The default priority for gedit is 20. Now I going to increase the priority to -8 as root:
# renice -n 8 -p 18925
nice for new process
The default priority for gedit is 20. Now I going to increase the priority to -5:
# nice -n -5 gedit
