💡This article was originally published on LWN at https://lwn.net/Articles/909095/ For better or worse, C is the lingua franca in the world of kernel engineering. The core logic of the Linux kernel is written entirely in C (with a bit of assembly), as are its drivers and

Welcome back to the "What is memory?" blog series. In our last post, we covered a lot of ground on some pretty low-level, complex topics. Let's do a quick review of what was discussed: 1. We learned that a program is executed by something called a

In the last post, we learned that a process is composed of a series of segments, which are loaded into its address space by a dynamic linker/loader. Once a process has been loaded and is ready to run, its address space looks something like this: If you’ll recall

Hi everyone, I'm back, after a somewhat long hiatus of multiple conferences, lots of travel, and getting engaged. I am in the process of writing another article as part of the "What is memory?" series, but in the meantime, I wanted to share another article that

💡This article was originally published by LWN at https://lwn.net/Articles/893024/The classic NUMA architecture is built around nodes, each of which contains a set of CPUs and some local memory; all nodes are more-or-less equal. Recently, though, "tiered-memory" NUMA systems have begun to appear; these

In our last post, we had some fun dunking on my poor, hapless TA. We asked and answered the question, “what is null”, and in answering that question, learned some important lessons about computer systems: 1. Everything is just data and context. When hardware and software components are interacting with

I remember when I was an undergraduate taking my first computer science course. We were learning about the null type in Java, and someone asked the (rather clumsy) TA, “I understand that you can compare an object to null to see if it was allocated, but what actually is null?

I solved a pretty interesting bug in the Linux kernel livepatch subsystem [https://www.kernel.org/doc/html/latest/livepatch/livepatch.html] earlier this year. The issue was this: when rolling out a livepatch to the fleet, we would detect a spike in TCP retransmit events while the livepatch was

In the previous blog post [https://www.bytelab.codes/plugging-into-linux-kernel-upstream-discussions/], we learned how to set up a dev environment to use mutt [http://www.mutt.org/doc/manual/] to subscribe to Linux kernel mailing lists on vger [http://vger.kernel.org/vger-lists.html]. We are now receiving patches for any

As I mentioned in my first blog post [https://www.bytelab.codes/introduction-to-the-blog/], most of my career has been spent in kernel space. I’ve of course done a ton of development work on Linux as a platform, but I started on the Linux kernel team with essentially zero knowledge

Welcome, everyone, to my blog, which I have named Byte Lab. As you may have seen on the About [https://www.bytelab.codes/about/] page, this blog is going to be systems engineering-themed. What this roughly means is that I’ll be talking about anything I find interesting, as it