To set scheduling policy to SCHED_FIFO, enter:

chrt -f -p [1..99] {pid} 

To set scheduling policy to SCHED_RR, enter:

chrt -r -p [1..99] {pid} 

So to answer question 3, we should verify the scheduling algorithms available and the priorities using the chrt -m command and then use any scheduling algorithm that suits our need. To set different priorities, we could use the commands as above.

Question 1

It is possible for an user to use real time priority for a process as well. This configuration could be set from /etc/security/limits.conf file. I see the below contents in that file.

# /etc/security/limits.conf # #Each line describes a limit for a user in the form: # #<domain> <type> <item> <value> 

If we check the item section, we see the below entry which enables to set a real time priority for the users.

# - rtprio - max realtime priority 

Question 2 and Question 3

To set scheduling policy to SCHED_FIFO, enter:

chrt -f -p [1..99] {pid} 

To set scheduling policy to SCHED_RR, enter:

chrt -r -p [1..99] {pid} 

So to answer question 3, we should verify the scheduling algorithms available and the priorities using the chrt -m command and then use any scheduling algorithm that suits our need. To set different priorities, we could use the commands as above.