LINUX System : Lecture 6 Bong-Soo Sohn Lecture notes acknowledgement : The design of UNIX Operating System

Architecture of the UNIX libraries system call interface file subsystem process control subsystem inter-process communication scheduler memory management hardware control hardware buffer cache device drivers character block user Level kernel Level hardware Level trap user programs 좌측에 파일서브시스템과 우측에 프로세스 서브시스템이 가장 핵심되는 축이 된다. 3종류의 레벨로 나뉘어져 있다 – user level, kernel level, hardware level

Libraries (1) process control libraries system call interface user programs libraries trap user Level kernel Level system call interface file subsystem process control subsystem inter-process communication scheduler memory management buffer cache device drivers character block hardware control kernel Level hardware Level hardware

File Subsystem (1) process control libraries system call interface user programs libraries trap user Level kernel Level system call interface file subsystem process control subsystem inter-process communication scheduler memory management buffer cache device drivers character block hardware control kernel Level hardware Level hardware

File Subsystem (2) Managing files Allocating file space Administering free space Controlling access to files Retrieving data for users Interact with set of system calls open, close, read, write, state, chown, chmod …

Buffering Mechanism (1) user programs libraries trap user Level kernel Level system call interface file subsystem process control subsystem inter-process communication scheduler memory management buffer cache device drivers character block hardware control kernel Level hardware Level hardware

Buffering Mechanism (2) Interact with block I/O device drivers to initiate data transfer to and from kernel.

Process Control Subsystem (1) user programs libraries trap user Level kernel Level system call interface file subsystem process control subsystem inter-process communication scheduler memory management buffer cache device drivers character block hardware control kernel Level hardware Level hardware

Process Control Subsystem (2) Responsible for process synchronization. Interprocess communication (IPC) Memory management Process scheduling Interact with set of system calls fork, exec, exit, wait, brk, signal … 파일시스템과 프로세스 컨트롤 시스템간의 서로 연계되는 때는 프로그램 실행을 위해서 메모리에 프로그램을 로딩할 때이다.

Process Control Subsystem (3) Memory management module Control the allocation of memory Scheduler module Allocate the CPU to processes Interprocess communication There are several forms.

Hardware Control (1) process control libraries system call interface user programs libraries trap user Level kernel Level system call interface file subsystem process control subsystem inter-process communication scheduler memory management buffer cache device drivers character block hardware control kernel Level hardware Level hardware

Hardware Control (2) Responsible for handling interrupts and for communicating with the machine.