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What to expect from Debian/Trixie
Update on 2025-07-28: added note about Debian 13/trixie support for OpenVox (thanks, Ben Ford!)
Topics /
Systems & Performance
The most popular blog posts about systems & performance on Hacker News. 4,387 posts.
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Optimizations can have unexpectedly large effects when combined with caches
This post is about a non-obvious interaction between performance optimizations and LRU/time limited caching.
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Text showdown: Gap Buffers vs. Ropes
I have been working on a hobby project to reimagine the C core of Emacs in Rust. On this journey, I reached the point where I needed some way to represent the text of a buffer. The simplest approach is to just use a large string or array of lines. However these each suffer from poor performance as either the size or…
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Why is Idris 2 so much faster than Idris 1?
I've just released a new version of Idris 2 , which is a significant release in that it's the first one which is able to compile itself. Thus, it's the first one where we can really see how the performance of Idris 2 improves on the performance of Idris 1.
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The simple beauty of XOR floating point compression
I recently implemented a small program to visualize the inner workings of a scheme that compresses floating point timeseries by XORing subsequent values. The resulting visualizations are quite neat…
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I wrote a GameBoy emulator for my hobby OS (2022)
The Nintendo GameBoy is an exceptionally well-documented system, perfect for anybody who’d like to take a crack at emulation. Publicly-maintained resources like the Pan Docs make it both approachable and convenient to get an overview of the GameBoy’s address space layout, to understand the mechanics of hardware…
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ZFS is the FS for Containers in Ubuntu 16.04
Ubuntu 16.04 LTS (Xenial) is only a few short weeks away , and with it comes one of the most exciting new features Linux has seen in a ve...
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Rules of optimization
Rules of optimization: 1) Design for performance from day 1 2) Profile often 3) Be vigilant on performance regressions 4) Understand the data 5) Understand the HW 6) Help the compiler 7) Verify your assumptions Performance is everyone's responsibility https://t.co/CwwJffnHGz
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Every Byte Matters
I have spent a large portion of my career working in Java. In that time, you get used to huge classes. New functionality? Just add a new method and field to the class. The cost of each new field is rarely considered. Performance is often considered from a classic computer science perspective by considering asymptotic…
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Why you can have millions of goroutines but only thousands of Java threads
Many seasoned engineers working in JVM based languages have seen errors like this: [error] (run-main-0) java.lang.OutOfMemoryError: unable to create native thread: [error] java.lang.OutOfMemoryError: unable to create native thread: [error] at java.base/java.lang.Thread.start0(Native Method) [error] at…
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Io_uring is not an event system
I’ve been hearing about io_uring on and off for the last couple of years. Its a relatively new technology in Linux to allow high-performance IO with very few overheads. Whenever its been mentioned, its usually been presented as a new alternative to select, poll and epoll. This led me to believe that it was just the…
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Monarch: Google’s Planet-Scale In-Memory Time Series Database
These paper reviews can be delivered weekly to your inbox , or you can subscribe to the Atom feed . As always, feel free to reach out on Twitter with feedback or suggestions!
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The engineering behind the US Strategic Petroleum Reserve
One of the most fascinating things I’ve learned about recently is the engineering behind the US Strategic Petroleum Reserve. Here are the key requirements it’s designed to meet: Store …
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The Anatomy of a macOS App
How Mac applications evolved from a multitude of resources to a bundle formed from a standard layout of directories, and how they have come to be largely self-contained in macOS 26.
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Firefox's Optimized Zip Format
This post is about minimizing amount of disk IO and CPU overhead when reading Zip files. I recently saw an article about a new format that was faster than zip. This is quite surprising as to my mind, zip is one of the most flexible and low-overhead formats I’ve encountered. Some googling showed me that over past 11…
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Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way
How to use the legendary OS in a (somewhat) practical way
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A BSD person tries Alpine Linux
By Ruben Schade in Eora/Sydney, Australia.
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FreeBSD Jails for Fun and Profit (2020)
Docker has recently stormed into software development. While its concepts are powerful and valuable, similar tools have been used in systems for decades. FreeBSD’s jails in one of those tools which build upon even older chroot(2). To put it shortly, with these tools, you can make a safe environment separated from the…
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Mail Data Loss in macOS 10.15
I’m working on more posts about the Catalina release, but I wanted to start with a short warning. I’ve heard a bunch of reports of data loss in Apple Mail. Thankfully, none seem to be caused by my apps . (Ironically, one of the bugs I’ve encountered is the inability to delete messages via AppleScript.) And, in fact…
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How fast is a macOS VM, and how small could it be?
Latest Geekbench performance figures for macOS VMs, and testing of how few cores and how little memory is really needed: could you run a macOS VM usefully on a MacBook Neo?
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Killing a process and all of its descendants
Killing processes in a Unix-like system can be trickier than expected. Last week I was debugging an odd issue related to job stopping on Semaphore. More specifically, an issue related to the killing of a running process in a job.
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Implementing a GPU's programming model on a CPU
SIMT The programming model of a GPU uses what has been coined "single instruction multiple thread." The idea is that the programmer writes t...
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Why is Python slow
In case you missed it, Marius recently wrote a post on the Pyston blog about our baseline JIT tier. Our baseline JIT sits between our interpreter tier and our LLVM JIT tier, providing better speed…
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Removing newlines in FASTA file increases ZSTD compression ratio by 10x
First released with Zstandard 1.3.2 in 2017, the --long range match finder increases the compressor’s search window to at least 128MiB, improving deduplication inside large files. This optional feature had substantial performance overheads at launch, but various optimisations have since brought its performance within…
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