Mac OS X Panther Operating System

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Mac OS X Panther Operating System. Tomomi Kotera CS 550 Section 3 Fall 2003. Presentation Overview. Overview of Mac OS X System Architecture Key technologies CPU scheduling Symmetric Multiprocessing Memory Management Conclusion. Overview of Mac OS X. - PowerPoint PPT Presentation

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<ul><li><p>Mac OS X PantherOperating SystemTomomi KoteraCS 550 Section 3Fall 2003</p></li><li><p>Presentation OverviewOverview of Mac OS XSystem ArchitectureKey technologiesCPU schedulingSymmetric MultiprocessingMemory ManagementConclusion</p></li><li><p>Overview of Mac OS XUNIX-based Operating System with the intuitive user interface called Aqua Classic Mac OS vs. Newer Mac OSFour major successes of Mac OS XPreemptive MultitaskingSymmetric MultiprocessingMemory ProtectionVirtual Memory </p></li><li><p>System ArchitectureFour layers of system softwareApplication EnvironmentsApplication ServicesCore ServicesKernel Environments</p></li><li><p>Preemptive MultiprocessingCooperative multitasking (Classic Mac OS) vs. Preemptive Multiprocessing (Mac OS X)Preemptive MultiprocessingMultilevel Feedback Queue Scheduling Algorithm Round Robin Scheduling Algorithm</p></li><li><p>Preemptive Multiprocessing (cont.)Multilevel Feedback Queue Scheduling Algorithm128 priority levels are divided into four bandsNormal (0-51) System High Priority (52-79)Kernel Mode Only (80-95) Real-Time Threads (96-127)Real-Time Threads are treated differentlyAvoid StarvationThreads migrate within a given band</p></li><li><p>Symmetric MultiprocessingDual processor capabilities Share Memory and I/O busKernel can execute on any processor</p></li><li><p>Memory Protection</p><p>Crush ResistantProcesses are isolated in own memory spacesCannot interfere one anotherIf one applications crashes, the system, and other applications are unaffected - no restarts</p></li><li><p>Virtual MemoryClassic Mac OS uses SegmentationMac OS X adopts Demand PagingLarge, sparse virtual address spacesMapping a page reference to a physical address</p><p>applicationpagerPagefaultresumeAddress spaceFunction call</p></li><li><p>Virtual Memory (cont.)VM Object (Virtual Memory Object)Object-oriented nature of MachContiguous repository for data indexed by byteAll data in an address space is provided through VM objectsTrack and manage the resident and nonresident pages Memory SharingInheritance (shared, copy, none)Copy-on-Write</p></li><li><p>Virtual Memory (cont.)Content of a VM object</p></li><li><p>Virtual Memory (cont.) Second-chance first in, first out (FIFO) AlgorithmThree lists of physical memory pages </p></li><li><p>Virtual Memory (cont.)Continuously check the free listWhen the number of pages in the free list dips below this threshold, remove pages from the inactive list to place them on the free listAlways maintains a few pages on the inactive listOnce the free list size exceeds the target threshold, the pager restsFIFO-like page replacement The inactive list serves as a second chance</p></li><li><p>ConclusionTechnical Success of Mac OS XMarriage of stability, reliability and security of UNIX, with the ease of use of the Macintosh GUI Benefits from UNIX featuresPreemptive SchedulingSymmetric MultiprocessingMemory ManagementTarget both home users and IT professionals</p></li></ul>

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