You are using a 1 GHz system with paged virtual memory for doing a real-time application. No other application is running on the system.
View the step-by-step solution to:

Question

You are using a 1 GHz system with paged virtual memory for doing a real-time application. No other application is

running on the system. A real time application is one where each task must be finished within a guaranteed time bound. In this particular real-time application, there are many tasks; each runs the exact same code but with different data each time. Each real-time task reads 20 bytes from an I/O device, performs some processing on it, and writes the updated 20 bytes of data back to the I/O device. I/O reads or writes are performed at 20 MB/sec. The code to process the 20 bytes has a total of 10 loads and stores, and takes 10000 cycles when all memory accesses are cache hits. These loads and stores can access anywhere in virtual memory. The system transfers control to another task with an overhead of 1000 cycles.

Every memory access takes 25 ns and every disk page transfer from the virtual memory swap space takes up to 2 ms. In the worst case a load or store could require 4 memory accesses and 2 disk transfers. How many real-time tasks can be guaranteed to run on this system per second in the worst case? (Assume the worst-case virtual memory behavior)

Recently Asked Questions

Why Join Course Hero?

Course Hero has all the homework and study help you need to succeed! We’ve got course-specific notes, study guides, and practice tests along with expert tutors.

  • -

    Study Documents

    Find the best study resources around, tagged to your specific courses. Share your own to gain free Course Hero access.

    Browse Documents
  • -

    Question & Answers

    Get one-on-one homework help from our expert tutors—available online 24/7. Ask your own questions or browse existing Q&A threads. Satisfaction guaranteed!

    Ask a Question
Let our 24/7 Computer Science tutors help you get unstuck! Ask your first question.
A+ icon
Ask Expert Tutors You can ask You can ask ( soon) You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors