• A typical process hierarchy in 4.3BSD UNIX
  • Typical Functions of an Operating-System Kernel
  • Memory Tables
    		•

    Unix foundations




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    process

    The proc

    • Process table
      • Id
      • Location of the kernel address map for the u area
      • Current process state
      • Forward and backward pointers in scheduled queue
      • Sleep channel (7.2.3)
      • Scheduling priority and related (Chapter 5)
      • Signal handling info(Chapter 4).
      • MM info
      • Pointers to link active, free, zombie processes in lists
      • Flags
      • Pointers to keep structures on a hash queue by PID
      • Hierarchy info

    A typical process hierarchy in 4.3BSD UNIX

    • Parent Process ID
    • pointer to parent’s proc
    • Pointer to the oldest child
    • Pointer to the younger sibling

    Typical Functions of an Operating-System Kernel

    Typical Functions of an Operating-System Kernel

    • I/O Management
      • Buffer management
      • Allocation of I/O channels and devices to processes
    • Support Functions
      • Interrupt handling
      • Accounting
      • Monitoring

    Operating System Control Structures

    • An OS maintains the following tables for managing processes and resources:
      • Memory tables
      • I/O tables
      • File tables
      • Process tables

    Memory Tables

    • Allocation of main memory to processes
    • Allocation of secondary memory to processes
    • Protection attributes for access to shared memory regions
    • Information needed to manage virtual memory

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