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The document discusses various concepts in operating systems, focusing on processes, threads, and kernel types. It explains process creation, management, and termination, along with threading models such as single-threaded, multi-threaded, and microkernel architectures. Additionally, it addresses the advantages and disadvantages of symmetric multiprocessing and microkernel designs.
Os
- 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 jobUser logs onCreated to provide a service such as printingProcess (parents process) creates another procCalled as process spawning
- 8. Process – The Termination Batch job issues Halt (OS service call for terUser logs offQuit an applicationError 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 opportunityBlocked/Waiting – process cannot execute until some event o
- 11. Suspended Process Processor is faster than I/O so all processes could be waitingSwap these processes to disk to free up more memoryBlocked state becomes suspend state when swapped to diskTwo new statesBlocked, suspend: blocked processes which have been swapReady, suspend: ready processes which have been swapped
- 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 definedA 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 executionSo 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 executionSo 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