《操作系统原理与设计 Operating System Principles and Implementation》课程教学课件（英文讲稿）Chapter 3 Process Concepts & Operations（part2）from Kernel's Perspective

OperatingSystemsCh3 - Process Operations-fromkernel'sperspective

Operating Systems Ch3 - Process Operations -from kernel’s perspective

Processin MemoryUserspaceGlobalDynamically-variableallocatedCode+memoryconstantsLocal一variableInvoking systemProcesscalls. E.g., fork(),exec*(), wait().AccessProcessprocess'structureKernel codeinternal(PCB)with systemcallsKernelSpace2

Global variable Local variable Dynamically￾allocated memory Code + constants Process structure (PCB) Kernel code with system calls 2 Process in Memory Kernel Space User space Process Invoking system calls. E.g., fork(), exec*(), wait(). Access process’ internal

Kernel-space vs User-spaceSystemMemoryUser-spacememoryKernel-spacememory3

Kernel-space VS User-space 3 System Memory Kernel-space memory User-space memory

Kernel-space vs User-spaceSystemMemoryKernel-space memoryUser-space memoryUser-spacememoryStoringwhatAccessedby whomKernel-spacememorya

Kernel-space VS User-space 4 System Memory Kernel-space memory User-space memory Kernel-space memory User-space memory Storing what Accessed by whom

Kernel-space vs User-spaceSystemMemoryKernel-space memoryUser-spacememoryUser-spacememoryProcess'memoryKernel data structureStoringKernel codeProgram code of thewhatDevice driversprocessAccessedby whomKernel-spacememory5

Kernel-space VS User-space 5 System Memory Kernel-space memory User-space memory Kernel-space memory User-space memory Storing what Kernel data structure Kernel code Device drivers Process’ memory Program code of the process Accessed by whom