Python | os.sched_get_priority_max() method

OS module in Python provides functions for interacting with the operating system. OS comes under Python’s standard utility modules. This module provides a portable way of using operating system dependent functionality.

OS module contains some methods which provides an interface to the scheduler and used to control how a process is allocated CPU time by the operating system.
os.sched_get_priority_max() method in Python is used to get the maximum priority value for the specified scheduling policy.

Note: This method is only available on some UNIX platforms.

Syntax: os.sched_get_priority_max(policy)

Parameter:
policy The scheduling policy whose maximum priority value is required.
Below are the scheduling policy constants that can be used as policy parameter value:

• os.SCHED_OTHER: It represents the default scheduling policy.
• os.SCHED_BATCH: It represents the scheduling policy for CPU-intensive processes that tries to preserve interactivity on the rest of the computer.
• os.SCHED_IDLE: It represents the scheduling policy for extremely low priority background tasks.
• os.SCHED_SPORADIC: It represents the scheduling policy for sporadic server programs.
• os.SCHED_FIFO: It represents First In First Out scheduling policy.
• os.SCHED_RR: It represents round-robin scheduling policy.

Return Type: This method returns an integer value which represents the maximum priority value for the specified scheduling policy.

Code: Use of os.sched_get_priority_max() method

# Python program to explain os.sched_get_priority_max() method

# importing os module
import os


print("Below are the maximum priority\
value for different scheduling policy")

# Get the maximum priority value for
# first In First Out scheduling policy
# os.SCHED_FIFO constant represents
# first In First Out scheduling policy
priority_max = os.sched_get_priority_max(os.SCHED_FIFO)
print("First In First Out scheduling policy:", priority_max)

# Get the maximum priority value for
# round-robin scheduling policy
# os.SCHED_RR constant represents the
# round-robin scheduling policy
priority_max = os.sched_get_priority_max(os.SCHED_RR)
print("Round-robin scheduling policy:", priority_max)


# Get the maximum priority value for
# the default scheduling policy
# os.SCHED_OTHER constant represents the
# default scheduling policy.
priority_max = os.sched_get_priority_max(os.SCHED_OTHER)
print("Default scheduling policy.:", priority_max)


# Get the maximum priority value
# for scheduling policy for extremely
# low priority background tasks
# os.SCHED_IDLE constant represents the
# scheduling policy for extremely low
# priority background tasks.
priority_max = os.sched_get_priority_max(os.SCHED_IDLE)
print("Scheduling policy for extremely\
 low priority background tasks:", priority_max)


# Get the maximum priority value
# for scheduling policy for CPU-intensive
# processes that tries to preserve
# interactivity on the rest of the computer.
# os.SCHED_BATCH represents the
# scheduling policy for CPU-intensive processes
# that tries to preserve interactivity
# on the rest of the computer
priority_max = os.sched_get_priority_max(os.SCHED_BATCH)
print("Scheduling policy for CPU-intensive processes:", priority_max)

Output:

Below are the maximum priority value for different scheduling policy
First In First Out scheduling policy: 99
Round-robin scheduling policy: 99
Default scheduling policy.: 0
Scheduling policy for extremely low priority background tasks: 0
Scheduling policy for CPU-intensive processes: 0

References: https://docs.python.org/3/library/os.html#os.sched_get_priority_max