Blog posts
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Quotes from “My life story” by Veritasium
During some down time this evening, I watched the below YouTube video clip filmed and produced by Veritasium and I absolutely loved hearing about his journey, especially about how becoming a father has fundamentally changed the way he views his time. Because I’m in a similar boat: My life looks nothing like it did a…
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Introduction to virtualization (notes)
As system designers, our goal is to design a “black box” system that create an illusion that our users have full and independent access to the underlying hardware of the system. This is merely an abstraction since we are building multi-tenant systems with many applications and many virtual guest machines running on a single piece…
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Daily Review – Day ending in 2020/09/07
Yesterday Writing Blogged and published an entry describing my naive scheduler for project 1 Emotions I disassociated and my mind wandered into its “own world” after my wife Jess asked me to watch Elliott later that afternoon. I think part of the reason why I got so worked up had less to do with her…
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A naive round robin CPU scheduler
A couple days ago, I spent maybe an hour whipping together a vary naive CPU scheduler for project 1 in advanced operating systems. This naive scheduler pins each of the virtual CPUs in a round robin fashion, not taking utilization (or any other factor) into consideration. For example, say we have four virtual CPUs and…
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Distancing oneself from a difficult problem
I fixed a silly bug just now and wrote working code that can pin multiple virtual CPUs to the physical CPUs. Identifying the bug in my code was another classic example of how I needed to distance myself from the problem. Instead of staying up late into the night (late is now 09:30 pm on…
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Weekly Review – Week ending in 2020/09/06
Writing I’m getting much more comfortable with publishing blog posts that are not completely polished. The fear of letting the world see less my less the perfect propose is utter non-sense. In fact, writing and publishing frequently offers two benefits. The first is that the sheer act of writing and setting words on (digital) paper…
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Advanced Operating Systems (Project 1) – monitoring CPU affinity before launching my own scheduler
Project 1 requires that we write a CPU scheduler and memory coordinator. Right now, I’m focusing my attention on the former and the objective for this part of the project is write some C code that pins virtual CPUs to physical CPUs based off of the utilization statistics gathered with the libvrt library (I was…
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Daily Review – Day ending in 2020/09/04
Yesterday Writing Blogged and published an entry for my daily review Blogged and published an entry explaining the libvrt’s bit map data structures that map virtual CPUs to physical CPUs Music Noodled around on the guitar, playing chords in a minor key up the neck (need to start structuring and mixing up my practice sessions…
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Making sense of libvrt bit map when calling virDomainPinVcpu
On my iPad this morning, I doodled the above figure to help me better understand how I should be calling the function virDomainPinVcpu (as part of project 1 for my advanced operating systems course). The function requires two parameters which I found a bit confusing: a pointer to the cpu map (i.e. bit map) and…
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Daily Review – Day ending in 2020/09/03
Writing Blogged and published an entry for my daily review Blogged and published an entry on L3 Microkernel Mental and Physical Health At the park, ran around in circles while holding Elliott in my arms … that sort of counts as exercise, right? Music Nothing at all Graduate School Migrated from my Virtualbox environment to…
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L3 Microkernel
I learned that with an L3 Microkernel approach, each OS runs in their own address space and that they are indistinguishable from the end-user applications running in user land. Because they run in user land, it seems intuitive that this kill performance due to border crossings (not just necessarily context switching, but address space switching…
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Daily Review – Day ending in 2020/09/02
Writing Blogged and published an entry for my daily review Blogged and published an entry that shows the steps for building librty’s documentation from source code (since the manual no longer exists on the official website) Mental and Physical Health Met with my therapist, who I see every week (except last week since I had…
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How to build the libvrt documentation from source
If just download the libvert application development guide, click here. How to build the documentation The libvrt developer documentation link is broken (i.e. HTTP 404). But I need the development guide for my advanced OS course so I downloaded the repository and built the documentation from source. If you want to do the same…
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Why do people fall prey to pyramid schemes?
YouTube’s recommendation engine suggested that I watch a video called “The Cult of Dan Lok”. Mind you, I never even heard of Dan Lok but my intuition lead me to believe that he runs some sort of pyramid scheme. Surprise surprise: he does. Anyways, in the video below, a student of Dan Lok describes how…
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How to launch and ssh to a KVM instance
This posts assumes that you’ve already synced the OS images on to your virtual box. If you haven’t, check out this blog post. While launching a new virtual machine for project1, I kept on running into variants of the following error: vagrant@ubuntu-bionic:~$ sudo uvt-kvm ssh aos_vm1 ubuntu@192.168.122.183: Permission denied (publickey). To get this to work,…
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Daily Review – Day ending in 2020/09/01
Yesterday Writing Blogged and published an entry for my daily review Blogged and published an entry that snapshots my understanding before starting on project 1 of advanced operating systems: writing a scheduler and writing a memory coordinator Music E-mailed the singing instructor that I’ve been seeing for the last couple years, informing her that lately…
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Syncing releases with uvt-simplestreams-libvrt
If you are executing uvt-simplestreams-libvrt you’ll need to execute the command with sudo and exercise patience (i.e. be okay with waiting 3 minutes while program runs without outputting any informational message to the standard output) No logging to standard output/error I had to exercise some patience when executing the command uvt-simplestreams-libvrt sync, the command that…
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A snapshot of my understanding before beginning project 1 (scheduler, memory coordinator)
Project 1 was released last evening at 08:59 PM PST and this morning, I decided to start on the project by reading through the overview and get the lay of the land. For this project, we’ll need to deliver to operating system components: a scheduler and a memory coordinator (not even sure what that means…
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Daily Review – Day ending in 2020/08/31
Yesterday Most interesting part of yesterday was a 1 on 1 video Chime chat that my co-worker scheduled with me. What started off with me stepping through our code base (for a set of features I added to the dataplane) morphed into a lengthy discussion around mental health and burning out and the idea of…
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Advanced Operating Systems – OS Structure – Exokernel
Unlike the SPIN OS Structure, exokernel approaches extensibility by decoupling the authorization to hardware from its actual use, by using something called secure bindings. OS libraries will request secure bindings, the Exokernel returning an encrypted key that grants that particular service to specific resources. One other way that the exokernel manages these underlying OS services…
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Advanced Operating Systems: The SPIN Approach
What did I learn? What are the main takeaways? The concept of border crossing pops up over and over again. This is a new term I never heard of prior to this class. The term is almost synonymous to a context switch but it is subtly different in the sense that a context switch (switch…
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Daily Review – Day ending in 2020/08/30
Yesterday Writing Wrote and published an article on Time Management Tip #1: Pomodoro Technique. How I use the technique and how I’ve adjusted it to fit my needs. Music Had my bi-weekly virtual guitar lesson with Jared. This was the first lesson back, after he took a 1.5 month sabbatical, a vacation he deserves and…
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Weekly Review – Week ending in 2020/08/30
Writing Developed a manageable cadence of blogging a single blog post every day, most of them daily reviews or notes taken during advanced operating systems Writing the daily reviews (each entry eats up about 15 minutes of my morning) help me not only plant my two feet in the ground and settle for the day,…
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Selecting research papers to read for Advanced Operating Systems
For advanced operating systems course, us students are required to sign up for (at least) two research papers that we summarize. Although two papers doesn’t sound like much, many former students of the course suggested ignore the other research papers and instead, focus on watching the lectures (which do cover the papers, sort of), banging…