Journal Entry Week 7

One of the most interesting concepts I learned this week was Processed I/O versus Direct Memory Access. Both are different types of memory transfer, but they differ in the way it works under the hood. Processed I/O involves the CPU directly and its is responsible for moving data between I/0 Devices. Some of these items include disks, keyboards, mice, network cards , and memory. This is not too bad of a process for smaller pieces of data, but in the case a large transfer of data takes place, it can eat up a lot of the CPU's resources; Direct Memory Access on the other hand utilizes specialized hardware to help with data transfers. It takes away CPU overhead for bigger data transfers, so that it doesn't slow down for other tasks that required better responsive ness. Newer devices now utilize DMA and the bus to allow the cpu to process more effienctly 

Comments

Post a Comment

Popular posts from this blog

Journal week 6

 One of the most interesting sections from this week was the topic of semaphores as a synchronization primitive.  Semaphores serve as way to help manage concurrency and work very similarly to locks but rather than just letting one thread access critical sections. Semaphores can allow “n” number of threads through. But by setting s semaphore to a value of 1, it can act just like a binary lock. As threads pass through a semaphore, a counter goes ups and down depending on what integer was initialized. As threads use the semaphore, the value decrements and once it reaches 0, no more threads can make use of the critical section. Once a counter reaches zero, it does the “wait()” operation. As threads finish with the critical section, it lets go of the semaphore and increments the value, allowing another thread to make use of its resources. It can serve as great synchronization tool, when two semaphores are used in tandem.  Another synchronization primitive we learned about was ...
Read more

Journal Entry Week 2

 One of the most interesting things I learned this week was about CPU scheduling. Everyday I use my phones or laptop, I take for granted the amount of processing power that is being the machine! This week the most tedious thing we did was hand calculate turn around time and response time. We also had to assume that there was only one available core, as other resources were not factored into the calculation.  Among the different kinds of scheduling , each of them have their own strengths and weaknesses. For example the Round- Robin scheduling excels at response time but sacrifices turnaround time in the process. By frequently switching to different jobs in small slices, the computer is able to work on all jobs what seems like simultaneously. With responses times at basically zero,  the amount of context switching that the computer has to do may drastically increase the turn around time.  Another scheduling algorithm we applied this week was the shortest Job priority. ...
Read more

CST334 Operating Systems Week 1

This week was kind of an eye opener. Being raised in an era where the internet just started booming, I always saw a computer as a black box. Almost like a modern-day Ouija board; I use the letters on a magic board and I get to see and speak to another person not in the room.  The internet has become the culmination, and as a teenager I used that knowledge to download sketchy mp3 files off a green citrus application.   I never really thought about computers and how an operating system served as an API. As I my make my way through these computer science course, I now see that I stand on the shoulders of giants. I’ve grown a deeper appreciation for all groundwork laid before me. Breaking down everything that an operating system does for the user is incredible. By the use of virtualization, it almost seems like how flawless using a computer uses its resources. From the users perspective, you kind of just expect it work out of the box.  Another Idea that I take for gr...
Read more