Process part 3

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Questions and Answers

What is the objective of multiprogramming?

To maximize CPU utilization

What is the cycle of process execution in terms of CPU and I/O?

CPU burst followed by I/O burst

When does the CPU scheduler make scheduling decisions?

All of the above

What is the primary goal of CPU utilization in scheduling algorithms?

To keep the CPU as busy as possible Signup and view all the answers

What does the pthread_attr_setscope function do?

Set the scheduling scope of the thread attributes object Signup and view all the answers

In asymmetric multiprocessing, what role do the other processors play?

Execute only user code Signup and view all the answers

What is the purpose of processor affinity?

Keep a process running on the same processor Signup and view all the answers

Which function is used to set the CPU affinity of a process specified by pid?

sched_setaffinity Signup and view all the answers

What does the CPU_SET() macro do?

Adds the CPU cpu to the set Signup and view all the answers

In multi-processor scheduling, what is SMP an abbreviation for?

Symmetric multiprocessing Signup and view all the answers

What is the purpose of CPU ISSET()?

Returns true if the CPU cpu is a member of set Signup and view all the answers

What distinguishes turnaround time from waiting time and response time in process scheduling?

Waiting time is the total time a process is queued for execution, distinct from turnaround time which includes execution and response time which is time to first action. Signup and view all the answers

What does FCFS scheduling prioritize?

Process with the earliest arrival time Signup and view all the answers

What is SJF scheduling based on?

The length of the next CPU burst Signup and view all the answers

What is significant about Preemptive SJF scheduling?

It executes the process with the shortest remaining CPU time Signup and view all the answers

What does Priority scheduling use to determine which process to execute?

The priority number assigned to each process Signup and view all the answers

What does Round-Robin scheduling allocate to each process?

A small amount of CPU time in a cyclic order Signup and view all the answers

'Nice value' impacts which aspect of a process?

The priority of the process Signup and view all the answers

'Completely Fair Scheduler' (CFS) in Linux handles resource sharing based on what principle?

'Max-min fairness' allocation principle Signup and view all the answers

'getpriority()' and 'setpriority()' system calls are used for modifying what aspect of a process?

'Nice value' Signup and view all the answers

'PTHREAD_SCOPE_PROCESS' in Pthread scheduling refers to what type of contention scope?

Process-contention contention scope Signup and view all the answers

What does 'PTHREAD_SCOPE_SYSTEM' in Pthread scheduling determine about contention scope?

System-contention contention scope Signup and view all the answers

Study Notes

Turnaround time is the amount of time it takes to complete a process, waiting time is the time a process has been waiting in the ready queue, and response time is the time from request submission to first response.
There are 6/45 scheduling algorithms for managing the execution of processes.
FCFS scheduling (First-Come, First-Served) is a non-preemptive algorithm where the process with the earliest arrival time is executed first.
In FCFS, the waiting time for each process is the difference between the total waiting time and the waiting time of the previous process.
SJF scheduling (Shortest-Job-First) is an algorithm that schedules processes based on the length of their next CPU burst.
SJF is optimal for minimizing average waiting time but requires knowing the length of the next CPU burst.
Preemptive SJF is an extension of SJF where the process with the shortest remaining CPU time is executed.
Priority scheduling assigns a priority number to each process, with the highest priority process being the one with the smallest number.
Round-Robin scheduling allocates a small amount of CPU time to each process in a cyclic order.
The time quantum in Round-Robin scheduling determines the size of each time chunk, with larger time quantum resulting in less overhead.
Linux's Completely Fair Scheduler (CFS) allocates the CPU time based on max-min fairness, handling resource sharing among multiple users.
The nice value is a process property that can be adjusted to impact the priority of the process, with lower values resulting in higher priorities.
The getpriority() and setpriority() system calls allow changing a process's nice value, and nice() is a function to increment the nice value.
Thread scheduling distinguishes between user-level and kernel-level threads, with scheduling competition being within the process for user-level threads and among all threads for kernel-level threads.
In Pthread scheduling, the contention scope can be set to either process or system during thread creation.
PTHREAD_SCOPE_PROCESS schedules threads using process-contention scheduling, and PTHREAD_SCOPE_SYSTEM schedules threads using system-contention scheduling.