1.
Group Member:
Alauddin Maulana Hirzan B031310530
Muhammad Syaifur Rohman B031310522
Aditya Pradana B031310
Wendy Sarasjati B031310528
Soraya Arum B031310
BITS 1213 Operating System

2.
Main Menu
- Process
- Thread
- Symmetric Multi Processing
- Microkernel

3.
Process - Intro
A process is the "heaviest" unit of kernel scheduling. ProcessResources include memory, file handles, sockets, device han

4.
Process – Cont'd
Process:- Also called a task- Execution of an individual program- Can be traced list the sequence of instructions that executeProcess, on the other hand, includes:- Current value of Program Counter (PC)- Contents of the processors registers- Value of the variables- The process stack (SP) which typically contains temporary data s- A data section that contains global variables.

5.
Identifier
State
Priority
Program Counter
Memory Pointer
Context Data
I/O Status Info
Accounting Info
…....
Process – Cont'd
While program is executing, this process can be c
Stored in data structure known as Process Cont
PCB is created for each process
The creation and management of PCB is done by

6.
PROCESS STATES
lThe Creation and Termination of ProcesseslA Two-State Process ModellA Five-State ModellSuspended Processes

7.
Process – The Creation
Submission of a batch jobUser logs onCreated to provide a service such as printingProcess (parents process) creates another procCalled as process spawning

8.
Process – The Termination
Batch job issues Halt (OS service call for terUser logs offQuit an applicationError and fault conditions

9.
Process – The Two State Model
l- Process may be in one of two stateslRunninglNot-running

10.
The Two State Model – Cont'd
Dispatcher cannot just select the process that has been in th
Solution: split Not Running into two states:Ready – prepare to execute when given opportunityBlocked/Waiting – process cannot execute until some event o

11.
Suspended Process
Processor is faster than I/O so all processes could be waitingSwap these processes to disk to free up more memoryBlocked state becomes suspend state when swapped to diskTwo new statesBlocked, suspend: blocked processes which have been swapReady, suspend: ready processes which have been swapped

12.
Suspending Reason

13.
Process Control – Modes of Execution
User mode
Less-privileged mode
User programs typically execute in this mode
System mode, control mode, or kernel mode
More-privileged mode
Kernel of the operating system

14.
Process Control – Process Creation
Assign a unique process identifier
Allocate space for the process
Initialize process control block
Set up appropriate linkages
Ex: add new process to linked list used for scheduling queue
Create or expand other data structures
Ex: maintain an accounting file

15.
Process Control – Switch a Process
Supervisor call
Requests I/O operation such as file open
Trap
error occurred from last instruction
may cause process to be moved to Exit state
Interrupt
event that is external to the running process such as completion of I/O

16.
Type of Interrupts
Clock interrupt
process has executed for the maximum allowable time slice
I/O interrupt
I/O action has occurred
Memory fault
memory address is in virtual memory so it must be brought into main memory

17.
Execution of the Operating System
Non-process Kernel (old)
execute kernel outside of any process
operating system code is executed as a separate entity that opera
Execution Within User Processes
operating system software within context of a user process
process executes in privileged mode when executing operating sy
Process-Based Operating System
major kernel functions are separate processes
Useful in multi-processor or multi-computer environment

18.
Single Thread VS Multi Thread

19.
Single Thread
Single threaded means there is only one thread within the processSingle threaded results in system idle time and user frustration. Fo

20.
Multi Thread
In a multithreaded environment, a process is definedA virtual address space that holds the process image. Protected access to processors, other processes (for inter-p

21.
Thread – Cont'd
Sometime there is an application that needed to run several task in

22.
Thread - Introduction
“One example of multithreading is when you are downloading a viYou can imagine multitasking as something that allows processesWhen multiple threads are running concurrently, this is known as m

23.
How Multi Thread Works
The multithreading can help because usually a normal HTTP executionSo in practice when you have 1 request in which you need to fetch an i

24.
Thread – Cont'd
Sometime there is an application that needed to run several task in

25.
How Multi Thread Works
The multithreading can help because usually a normal HTTP executionSo in practice when you have 1 request in which you need to fetch an i

26.
Type of Multi Threading
Many To One
In the many-to-one model, many u
Thread management is handled b
However, if a blocking system cal
Because a single kernel thread ca

27.
Type of Multi Threading
One to One
The one-to-one model creates a separate kernel thread to handle each
One-to-one model overcomes the problems listed above involving block
Linux and Windows from 95 to XP implement the one-to-one model for

28.
Type of Multi Threading
Many to Many
The many-to-many model multiplexes any number of user threads onto a
Users have no restrictions on the number of threads created.
Blocking kernel system calls do not block the entire process.
Processes can be split across multiple processors.

29.
Advantages
a. Responsive . Interactive applications to remain responsive even though theb . Resource sharing . Threads share memory and resources with other threadc . Economical . Making a process requires allocating need memory and resoud. Utilization of multiprocessor architectures . Advantage of multithreading can

30.
Disadvantage
a. Kernel threads are generally slower to create and m
b. Transfer of control from one thread to another within

31.
Symmetric Multi Processing
Symmetric Multiprocessing is a computer architecture of multiproc
Unlike asymmetric processing, any idle processor can be assigned

32.
Symmetric Multi Processing Cont'd
Symmetric multiprocessing systems are tightly coupled multi

33.
Symmetric Multi Processing Cont'd

34.
How SMP Works
In a symmetric multiprocessing environment, the CPU's share the same memo
Programs running on symmetric multiprocessing systems may experience a p
The effect in most applications is not so much a performance increase as the

35.
How SMP Works Cont'd
Symmetric multiprocessing systems allow any processor to work o

36.
Advantages
Symmetric multiprocessing is one of the cheapest ways to improve hardware performance. This
Symmetric multiprocessing is relatively easy to implement.
In situations where more than one program executes at the same time, a symmetric multiproces

37.
Disadvantages
On personal computers, symmetric multiprocessing is less useful for applications that have not
It is useless if the system rarely runs more than one process at a time.

38.
Microkernel - Introduction
Kernel is a computer's core program that manages I/O requests from so

39.
Type of Kernel
Monolithic Kernels
Microkernel
Hybrid
Exokernel

40.
Type of Kernel
Monolithic Kernels
Microkernel
Hybrid
Exokernel

41.
Microkernel Cont'd
Microkernel is the near-minimum amount of software that can provide the mechanis
A microkernel that is designed for a specific platform or device is only ever going to h

42.
Microkernel Cont'd
Microkernel is the near-minimum amount of software that can provide the mechanis
A microkernel that is designed for a specific platform or device is only ever going to h

43.
Advantages
Service separation has the advantage that if one service (called a server) fails others can still w
Only that driver need to be restarted rather than having the entire system die. This means more
Different services are built into special modules which can be loaded or unloaded when needed
Message passing allows independent communication and allows extensibility
The fact that there is no need to reboot the kernel implies rapid test and development.
Easy and faster integration with 3d party modules.

44.
Disadvantages
Memory foot print is large
Potential performance loss (more software interfaces due to
Message passing bugs are not easy to fix
Process management is complex

45.
Microkernel Diagram

46.
Microkernel Diagram Cont'd

47.
References
lhttp://en.wikipedia.org/wiki/Thread_(computing)
lhttp://ashishkhandelwal.arkutil.com
lhttp://www.cs.uic.edu/~jbell/CourseNotes/OperatingSystems/4_Threads.html
lhttp://www.slideshare.net/sartakov/01-intro1-14682045
lhttp://beckellroom.blogspot.com/2009/01/pengertian-tentang-kernel-kernel-adalah.html
lhttp://www.8bitavenue.com/2012/11/microkernel-vs-monolithic-os-architectures/
lhttp://en.wikipedia.org/wiki/Kernel_(computing)#Monolithic_kernels
lhttp://en.wikipedia.org/wiki/File:OS-structure.svg