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Systems & Performance

The most popular blog posts about systems & performance on Hacker News. 380 posts.

2025
301

What is gVisor?

It has been a really long time since I last wrote something here as life happens, things get busier, etc etc. I am now trying to get back into writing things down and here we go! So, imagine a tool or a service that allows you to run some arbitrary code via a shell. Either through a ssh or more commonly, via a web…

302

In-Memory Filesystems in Rust

I’ve been working on a CLI tool recently, and one of the things it does is manage files on disk. I have written a lot of file management tests for Bundler, and the two biggest reasons that the Bundler test suite is slow are exec and fstat. Knowing that, I thought I would try to get out ahead of the slow file stat…

303

Unix "find" expressions compiled to bytecode

In preparation for a future project, I was thinking about at the unix find utility . It operates a file system hierarchies, with basic operations selected and filtered using a specialized expression language. Users compose operations using unary and binary operators, grouping with parentheses for precedence. find may…

314

The messy reality of SIMD (vector) functions

We’ve discussed SIMD and vectorization extensively on this blog, and it was only a matter of time before SIMD (or vector) functions came up. In this post, we explore what SIMD functions are, when they are useful, and how to declare and use them effectively. A SIMD function is a function that processes more than… Read

318

Fun with -fsanitize=undefined and Picolibc

Both GCC and Clang support the -fsanitize=undefined flag which instruments the generated code to detect places where the program wanders into parts of the C language specification which are either undefined or implementation defined. Many of these are also common programming errors. It would be great if there were…

322

Not all OCuLink eGPU docks are created equal

I recently tried using the Minisforum DEG1 GPU Dock with a Raspberry Pi 500+, using an M.2 to OCuLink adapter, and this chenyang SFF-8611 Cable. After figuring out there's a power button on the DEG1 (which needs to be turned on), and after fiddling around with the switches on the PCB (hidden under the large metal…

323

Load-Store Conflicts

meshoptimizer implements several geometry compression algorithms that are designed to take advantage of redundancies common in mesh data and decompress quickly - targeting many gigabytes per second in decoding throughput. One of them, index decoder, has seen a significant and unexpected variance in performance across…

324

Systemd can be a cause of restrictions on daemons

You're probably reading this page because you've attempted to access some part of my blog (Wandering Thoughts) or CSpace , the wiki thing it's part of. Unfortunately you're using a browser version that my anti-crawler precautions consider suspicious, most often because it's too old (most often this applies to versions…

327

Matrix Core Programming on AMD GPUs

In this blog post, we walk through how to use Matrix Cores in HIP kernels, with a focus on low-precision data types such as FP16, FP8, and FP4, as well as the new family of Matrix Core instructions with exponent block scaling introduced in the AMD CDNA™4 architecture. Through code examples and illustrations, we…

328

Resizeable Bar Support on the Raspberry Pi

While not an absolute requirement for modern graphics card support on Linux, Resizeable BAR support makes GPUs go faster, by allowing GPUs to throw data back and forth on the PCIe bus in chunks larger than 256 MB. In January, I opened an issue in the Raspberry Pi Linux repo, Resizable BAR support on Pi 5. Unlike most…

329

Siren Call of SQLite on the Server

At Terrateam, we are big fans of Fly.io. The service is hosted there and it’s served us well. Just deploy your TOML file, get your infrastructure, do something else with the rest of your day. One of the interesting sides of Fly is that they invest heavily in server-side SQLite. They’ve written a number of blog posts…