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The most popular blog posts about systems & performance on Hacker News. 4,390 posts.
Zeroing out a CPU register seems like the simplest and most basic operation imaginable, but in fact x86 CPUs contain a surprising amount of special logic to make this operation run smoothly. The mo…
Sebastian Krahmer of the SUSE Security Team has discovered a local root exploit in systemd v228 . A local user on a system running systemd v228 can escalate to root privileges. That's bad.
Is exFAT as fragile as some say?
In most systems, integers are stored using a fixed binary representation. It is common to store integers using 32-bit or 64-bit words. You sometimes need to convert it to a string. For example, the integer 12345 might need to be converted to the five characters '12345'. In an earlier blog post, I presented the simpler…
From the highly eclectic blog of Mark Dominus
Given that events play such a central role in event-driven architecture, there’s an astonishing lack of agreement on what should be contained in an event. This may be rooted in the fact that, depending on your perspective, events fulfill different purposes.
Windows XP I have a lot of fond memories of Windows XP and after feeling nostalgic, I was happy to find out that it’s relatively easy to take it for a spin on an ARM64 Mac using QEMU. I decided to install XP and an assortment of classic software one final time, taking screenshots of the whole process. This included…
Compilers have a hard time optimizing floating point math. Rust has a new API to fix this.
(This blog entry has been recovered for the sole purpose of repairing a link in Hackernews. This blog entry is otherwise hidden on the website. 2026-04-13)
This is directly inspired by Engineering for Slow Internet. I figured I’d give running with dogshit internet on my desktop and phone a go to see how poorly (or well!) specific applications behave. This is not an in-depth review of the behavior, but just my general impressions running for a few hours on 200kbit…
In late 2002, Byte.com decided to combat falling ad revenue by charging admission to its archives of computing content. I have first-hand experience tring to harvest enough revenue from the Internet to pay operating costs, and fully support Byte's decision to move to a subscription model. However, my BeView columns on…
AWS EC2 Secret sauce. How AWS provisions Windows EC2 in the cloud. Instance Pool.
The Strangler is an extremely effective technique for phasing out legacy systems over time. Instead of spending months getting a new system up to parity with the current system so that clients can…
In other words, the $k$-th element of the output sequence is the sum of the first $k$ elements of the input sequence.
With Computex, there’s been a ton of news about Ice Lake (hereafter ICL) and the Sunny Cove core (SNC). Wikichip, Extremetech and Anandtech among many others have coverage (and there will be …
SunOS is a historical UNIX operating system widely used from the mid 80s into the early/mid 90s. Older versions of QEMU struggled to emulate the SPARC platform that SunOS ran on, but QEMU v7.2 supports SPARC well enough to install and run SunOS without any unusual workarounds.
Despite the fact that it is not a 'real' vulnerability, escaping privileged Docker containers is nevertheless pretty funny. And because there will always be people who will come up with reasons or excuses to run a privileged container (even though you really shouldn't), this could really be handy at some point in the…
Writing Hello World on a homebrew CPU
What is bufferbloat, why is it bad, and what to do about it
How to get the most of Rust while keeping your code portable
So I was optimizing a domain-specific compressor the other day, as one does. One important problem was chunking the input string and optimally choosing the most compact encoding for each chunk (different encodings compress different characters better, so where to split is not immediately obvious). The previous post…
Using CPU % or Energy values in Activity Monitor appears to show that running code on E cores is less efficient than on P cores. Don’t believe a word of it.
[ I wrote this post in mid-2014 for debuggers.co, which seems to have gone at least partly defunct, so I am reproducing it here. That site collected answers from programmers to the prompt “What’s the most interesting bug you’ve encountered?” ]
Someone mentioned cargo-bloat the other day and it reminded me that I have been wanting to measure the code size for generic functions in librsvg, and see if there are improvements to be made.
Recently I’ve been experimenting with freestanding C programs on Windows. Freestanding refers to programs that don’t link, either statically or dynamically, against a standard library (i.e. libc). This is typical for operating systems and similar, bare metal situations . Normally a C compiler can make assumptions…
