1. OS/2 CS-450-3 Operating Systems Section 3 Fall 2003 By Keith Ancowitz Brian Henderson James Mauss Danielle Miller Kyle Nevins

2. Outline OS/2 History File Management System Memory Management Process Management Scheduler

3. OS/2 Warp History OS/2 1.0 Began as a joint venture with Microsoft to replace the current DOS 3.x system. OS/2 1.1 First implementation of a GUI in the operating system. OS/2 1.3 First version of OS/2 released by IBM without Microsoft’s assistance. OS/2 2.0 First version of the 32-bit system. OS/2 2.1 Released to allow users to have Windows 3.1 compatibility. OS/2 Warp 3.0 First version of Warp to appear. OS/2 Warp Connect P2P functionality and networking support. OS/2 Warp 4.0 Included Java and VoiceType

4. OS/2 vs. DOS File Systems OS/2 v1.2DOS File System High Performance File System (HPFS)File Allocation Table (FAT) Max. Characters in Filename 25511 Filename Format Capable of multiple extensions of varying lengths. This.my.filename 8dot3 (8 character filename and a single 3 character extension) Max. Path Length 26064 File and Dir Tracking Sector LevelCluster Level File Attributes Last Modified, Type of Data Stored, Native Language, etc. Min. Allocation Unit Sector (512 bytes) ≈ file node (FNODE)Cluster (4kb or more) Directory Structure Sorted Binary TreeUnsorted Linear List Caching Technique Store entire file and dir structure in cache File System Update Installable File SystemN/A XCOPY for a 5 MB file 21.6 Seconds39.4 Seconds Build an index of 4600 records in a 2.3 MB file 161 Seconds973 Seconds

5. Installable File System

6.  13 bit number for the segment number  1 bit to tell which table to look in LDT or GDT  2 bits to deal with protection 13 12 Segment Table 10 12 Page offsetPage Number Page Directory Page Table Page Frame Physical Address 32 SelectorOffset + Linear Address Memory Management

7. SMP Symmetrical Multi-Processing Testing Applications Increased Performance for Cheaper “Greatest Advantage” of OS/2 over Windows

8. Process/ Page Life Cycle

9. Process Scheduling RING 3 Scheduling –Four types of threads Normal Level –32 microseconds Time Critical –8 microseconds Idle-time Foreground Server –Priority and Round Robin

10. RING 0 Scheduling –Same Levels –Contexts Init Mode Interrupt Mode –Highest Priority –Dependant on IRQ levels Kernel Mode Process Scheduling