html5-img
1 / 7

Quiz

Quiz. a. Why is LOOK better than SCAN? Answer the following two questions using exactly one of the words FCFS, SSTF, SCAN, LOOK, C-SCAN, C-LOOK b. Which algorithm possibly results in starvation? c. Which of SCAN or C-SCAN gives better throughput?. Where is RAID, or is SSTF implemented?.

jamil
Download Presentation

Quiz

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Quiz • a. Why is LOOK better than SCAN? • Answer the following two questions using exactly one of the words FCFS, SSTF, SCAN, LOOK, C-SCAN, C-LOOK • b. Which algorithm possibly results in starvation? • c. Which of SCAN or C-SCAN gives better throughput?

  2. Where is RAID, or is SSTF implemented? • OS* … disk • cheap … expensive • older … newer • serial … parallel (offload work and complexity) • logical … physical • volume: logical disk; may span physical disks, or may have several volumes on a physical disk • OS must keep track of physical disks to do * above. • Third alternative in middle is possible: • OS … controller card (host bus-adapter) … disk

  3. Excerpt from Chapter 13

  4. How Does Plug and Play (PnP) work? • Reassigns port and maskable interrupt to avoid collision with another device. • Port: device register mapped to small amount of memory to provide control information. • (Contrast: Memory-mapped device, where large amount of memory provides data to or from the hardware.) • MIRQ and NMIRQ wires provide interrupt number, telling what interrupt occurred, provided by the CPU. • (Contrast: Interrupt level, which is a priority set by OS.)

  5. Device I/O Port Locations on PCs (partial)

  6. Pentium maskable vs. non-maskable interrupts

  7. Windows XP Interrupt Request Levels

More Related