Operating Systems Principles

Harry Xu

Operating Systems Principles

Computer Science department

Harry Xu

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from 15 users


Overall 3.2
Easiness of class 2.4
Workload 1.6
Not Clear
Clarity of professor 2.5
Not Helpful
Helpfulness of professor 2.8


  • Uses Slides
  • Tolerates Tardiness
  • Useful Textbooks
  • Appropriately Priced Materials
  • Often Funny


Spring 2019

Grade distributions are collected using data from the UCLA Registrar’s Office.

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Quarter Taken: Winter 2020 Submitted April 1, 2020 Grade Received: A

Reasons to ditch lecture: It was very badly paced, because Xu tends to ramble about ?? (Idk because I didn't pay attention for the 3 weeks I did go) especially when students asked questions.

Reasons to read the wonderful, hilarious, eloquent, and most notably widely available, FREE, and ONLINE textbook instead: Very easy to read, you will actually learn, the footnotes have jokes, probably the best textbook you will read in the entire CS curriculum

Quarter Taken: Winter 2020 Submitted March 26, 2020 Grade Received: A-

As nice and approachable as Harry was, I didn't really gain much from having him as a professor. By week 5, nearly half the class (myself included) stopped attending lecture. My personal reason for this was that the textbook, Three Easy Pieces, explained OS concepts far more concisely and accurately than Harry could. He was consistently behind schedule, which made some of the projects unduly difficult. Thankfully, my TA was great about guiding us through the projects without directly telling us what to do (shoutout Shaan). Honestly, if lectures were removed and all my learning was exclusively from the readings/slides, my understanding of the course material wouldn't change all too much.

Quarter Taken: Spring 2019 Submitted July 16, 2019 Grade Received: A-

Good News: If you can, definitely take him. BAD NEWS: Zhaoxing Bu graduated so RIP future CS111 students.
This guys is one of the nicest professor you can have in any cs classes. I mean yes he is new and sometimes he gets all confused, but you can pretty much self-study everything based on the slides and textbook(which is free). He reuses projects and slides and course schedules from previous professors and he hands the projects entirely to the TAs. The projects take a shiiiiiiiit ton of time so don't expect to have a lot of free time during the weekends. For us we are lucky because we have Zhaoxing Bu to hold our hands and guide us through the projects step by step but as I said he graduated so whooopsies. But in case he gets tired of working at Google and decides to redo his PhD, definitely go to his section no matter what. His tests are not so hard compared to other professors' tests(which are INSANELY hard) but considering the extensive amount of material covered in this course it is a pain nonetheless. Overall this is a hard class but you will learn a lot. And he is a great guy so definitely take him on any course if you can.

P.S. because he is such a great guy he pretty much says yes to all of your demands. During the midterm there was a small confusion on his slides that led some students to give wrong answers. So when students asked him on this he just decided to give full score on that question (a 15 points question) to everyone who submitted a regrade request regardless if the mistake was because of the confusion or just a regular fuck-up. How about that huh.

Quarter Taken: Winter 2020 Submitted March 25, 2020 Grade Received: A+

Harry is a bad professor. It's really obvious he cares little about teaching, and he lectures like he wishes he weren't there. Harry stole slides from previous professors (Reiher), presenting them word for word. Furthermore, he lectures as though he's never seen the slides in his life. Harry reads off the slides word for word, adding little to no additional information than what the slides provide. I can't understand why I'm spending money and time learning about operating systems from Harry, when I could be learning more as a broke high school dropout with a laptop. Additionally, he copied a significant amount of the midterm from a previous midterm, which may have been the reason why the median was in the 90s. While this did make the midterm extremely easy, it also further proves the point that Harry does not care. I could say the same thing about every project, but it seems like the projects have been the same for many quarters, which is a failure of the 111 course itself (writing new assignments obviously takes some time, but updating them once in a while doesn't seem unreasonable). Additionally, Harry's scheduling was atrocious. On the two lectures prior to the midterm (around week 4/5), we had covered half of what was planned. Luckily, Harry rushed through the slides, skipping whatever he felt like so that he could 'catch up'. Regardless of whether this was caused by poor planning, or a lack of motivation to teach the class, I think that incidents like these are inexcusable. Frankly, CS 111 with Harry was difficult for the wrong reasons. We use resources from other professors, we have no motivation to do learn much from this class, and nobody can say what Harry contributes to their education. Not even the grading can be taken seriously, since everyone has aced every single assignment and exam. We'd all be a lot happier (Harry included) if he never taught again. In the event that he does, I recommend for him to be better at pretending to care, or at least to put in a little more effort.

Quarter Taken: Winter 2020 Submitted March 27, 2020 Grade Received: A-

Everything I learned is this class was solely due to the readings and the projects. I did not learn anything from Harry. His lectures were dull and entirely failed to engage me. He doesn't explain the concepts well and he isn't the best at answering questions.

With that being said, this class was not that bad. The midterm was pretty easy and the questions were rather straightforward. As long as you are able to do well on the projects and actually do the readings, you can get an A. There is a decent amount of work (readings + weekly projects), but honestly the class is easier than 35L and the material you are learning is more interesting.

Harry isn't the best pick for this class, but in the end you can pretty easily learn everything on your own.

Start the projects early.

Quarter Taken: Spring 2019 Submitted June 26, 2019 Grade Received: N/A

Xu is a new professor at UCLA so he uses Reiher's slides and doesn't seem too familiar with them. Lectures are sometimes confusing and I find it hard to pay attention to him. The entire course website is copied from Reiher's (so same readings) and the links didn't work. He did not reply to questions on Piazza but the TA's did... most of the time.
With all that being said, he's probably the easiest professor for this class. The midterm was similar to Reiher's, but the final was very different. He gave a pretty comprehensive list of areas he'd test for for the final and I crammed for it but I feel like I shouldn't have done that because the final was totally different from what I expected anyways. It's easy in the sense that you can get away with not really reading the entire textbook (which to my understanding is a requirement to do well in other professors' classes). But you need good intuition with the material.
Overall, the professor is a nice guy.
Like other reviews for CS111, I recommend going to Zhaoxing Bu's discussions if you want to do well, but not necessarily to learn.

Quarter Taken: Winter 2020 Submitted March 13, 2020 Grade Received: B-

There were honestly a lot of missteps in this class. But Harry Xu undeniably cares—a lot—about his students. That's really all I have to say. Take it with him if you can.

Quarter Taken: Winter 2020 Submitted Sept. 13, 2020 Grade Received: A-

Honestly CS 111 is never a very easy class, but taking it with Prof. Xu makes it a little better, since the exams are not that hard. But one thing worth notice is that Harry reused his old midterms (which are actually available in the test bank), making the exams in some degree unfair and many students having crazy high scores in the midterm. Projects are A LOT OF WORK- basically no weekend. Just pray you get a helpful TA... And for the pace of the class, yes, that's a big problem. Harry fall behind his schedule 2 weeks or so, so when the quarter approaches the end, ummm..., things went fast.

Quarter Taken: Winter 2020 Submitted May 8, 2020 Grade Received: A-

I actually really liked this class, certainly better than any Eggert-taught class I've taken (though I think that's more of a personal preference). Sure, the projects were a lot of work, but that's what you expect from CS 111. I really appreciated how the lectures were generally pretty easy to follow and to understand - him posting his slides certainly helped. The only problem with this class that I have is the down curving. I got a 94.78% and got an A-. Apparently the cut-off was 95% and there was no rounding. Ah well.

Also, the textbook is phenomenal! Highly recommend you read it, especially since it's available for free online.

Quarter Taken: Winter 2020 Submitted March 30, 2020 Grade Received: B+

Going to lecture is basically useless; discussions are helpful for the weekly projects though. I thought the assigned textbook readings were decent, but I don't think the professor has read them, so it's not really useful for the exams or anything. IMO the projects are way easier than 35L because the specs are very clear about what you have to do.

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  • Uses Slides
  • Tolerates Tardiness
  • Useful Textbooks
  • Appropriately Priced Materials
  • Often Funny

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