Operating System Concepts 1.1 Silberschatz, Galvin …users.cs.fiu.edu/~ege/cop4610/Slides/ch1.pdf · Printer Disk)Significant increase in speed and ... processors share memory and
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What is an Operating System?Mainframe SystemsDesktop SystemsMultiprocessor SystemsDistributed Systems Clustered SystemReal -Time SystemsHandheld SystemsComputing Environments
2. Operating systemcontrols and coordinates the use of the hardware among the various application programs for the various users
3. Applications programsdefine the ways in which the system resources are used to solve the computing problems of the users (compilers, database systems, video games, business programs)
Symmetric multiprocessing (SMP)Each processor runs and identical copy of the operating systemMany processes can run at once without performance deterioration.Most modern operating systems support SMP
Asymmetric multiprocessingEach processor is assigned a specific taskMaster processor allocates work to slave processorsMore common in extremely large systems
Often used as a control device in a dedicated applicationcontrolling scientific experimentsmedical imaging systemsindustrial control systemssome display systems
Well-defined fixed-time constraintshard real-time: all tasks done on timesoft real-time: critical tasks have priority
Hard real-time:Secondary storage limited or absentdata stored in short term memoryor read-only memory (ROM)Conflicts with time-sharing systemsnot supported by general-purpose operating systems
Soft real-timeLimited utility in industrial control of roboticsUseful in applications (multimedia, virtual reality) requiring advanced operating-system features